Let me start by saying I have the June 2012 firmware on my Classic...
Today I changed my EA setting from 1.4 to .2 amps after reading some information from the battery manufacturer. I also changed max. absorb time from 4 to 6 hours. The Classic went to float after about 3 hours of absorb time with these settings. I didn't think the amps got down to .2 before the transition so I forced absorb. It was then bouncing between 1.0 and 1.4 but went to float after roughly 15 minutes which is my minimum absorb time. Then I forced absorb again with the same result. The current never got down to .2 and 6 hours didn't pass so I'm trying to figure out why it kept going into float. The lowest I saw was .8 or .9 amps for a second.
I'll experiment more tomorrow but I expect to see the same results.
As a side note I ended up deciding I will change the EA setting to .7 because I have determined my Classic reads about .5 amps too high on the display. If I account for that then .7 should be a good setting to net out at .2. Possible enhancement...maybe we could get an offset for the amps out which would then adjust the watts reading for those of us that have done some experimenting and feel comfortable with this?
One more thing. Since the current bounces around when it's absorbing does the Classic look at the lowest current or the highest current or the average to make it's determination of when it transitions to float?
I think that 0.2 amps is going to be too low because the average battery current must drop below that voltage and NOT
go above that voltage for about 90 seconds.
As soon as the battery voltage (average, reading on the MNGP), rises above your EA setting, it's going to take it
another 90 seconds below that setting to go to float.
Also, on the max absorb time thing, try changing the minimum absorb time to something longer. Remember
that the Classic starts out at minimum time and counts down to 0 from there if it went straight to absorb.
If it is in bulk, it counts up towards the max absorb time and THEN counts down to 0 from that time
when it finally gets to absorb. Your batteries may already be charged or close to it so it may be counting
from minimum absorb time so it will go to float faster because of that unless the battery voltage
drops below EA setting for 90 seconds in which case it will go to float faster.
But, 0.2 amps for EA is just too low for the Classic to be able to go below for that usage.
You may also have DC loads that require current from the Classic that can keep it from
dropping below 0.2 amps. Current bounces around somewhat so that alone may keep
it above 0.2 amps at times and resetting the EA timer/counter.
Later, the minimum and maximum absorb time is going be one number and NOT count up from
a minimum time count if in bulk. It will just count down from max and when battery voltage
drops below absorb set point, the counter will just stop until the battery voltage gets back to
the absorb set point.
There will be a way to make it do what it does now, (count up and down) but it will be smarter.
Hopefully this code will be coming out in a week or two.
How large is your battery bank in Amp-Hours ?? 0.2 amps seems a bit low for a typical
bank.
boB
Odyssey recommends .001C for ending amps with no more than 8 hours of absorb time(or 4 hours absorb if there is no EA setting). C in this case is 136 amps. I rounded up from .136 to .2. I agree that it may be hard for the Classic to stay below .2 for 90 seconds but if I set it to .7 then it should be ok?
I'm a little confused on the counting up and down thing. I thought if the max. absorb was set at 6 hrs. that it would either count up or down once it hit my absorb set point and when it reached the 6 hr. time it would go to float if it hadn't hit the EA setting before that time. I guess I'll have to pay more attention to this but if it's about to change then I won't worry about it too much.
Tomorrow I'll increase the min and max absorb time and try things again.
Hi Wx..
Boy, .001 X C is an amazingly LOW EA value.
And, did you add a second battery vs your signature?
Here, have reloaded the FW in each CC, did the VMM, and now, EA seems to work fine.
boB, man, the logs on the Classic are very cool! Tons of info. Have not run an app yet, but it is quite easy to confirm that EA is working well. Great job on the Classic, and it just gets better and better!
Thanks, Vic
Vic, I've got two 68ah agm batteries. I do have that listed in my signature but maybe it's confusing the way I typed it. I agree that .001C is very low but these batteries seem to be a little different than most. They also want .4C bulk current for deep cycling applications. That would be 54 amps for these two small batteries. A lot more firepower than I have.
WX, OH, yea, it's right there -- 2! Thanks for reading it to me.
Yea many batts say they want tons of charge current. Am not familiar with the ones you have, will look them up on line. Thanks Vic
Vic, attached is the link to the technical manual for the batteries. I have the DieHard version but I've read they are re-badged Odyssey batteries. I believe mine are the same as the PC1500's
http://www.odysseybattery.com/documents/US-ODY-TM-001_0411_000.pdf
I just checked the Classic absorb timer and it has 1:45 left. I set the minimum at 1 hr this morning and the maximum at 7:30. Based on the timer and the fact that it's been in absorb for 1:45 so far today the Classic is apparently planning a 3:30 absorb time. Based on my settings I can't figure out why. I then bumped up the minimum to 4 hrs and the max to 8:30 and the absorb timer didn't change.
I just reset the Classic since I'm leaving for a couple of hours and set the min. to 3 hours and the max to 8:30. I then checked the timer and it was counting down from 5 hours. So I accomplished what I wanted which was to keep it in absorb while I am gone but why did the timer then go to 5 hours when that wasn't either of my settings after I reset the unit?
Quote from: Wxboy on September 25, 2012, 12:03:13 PM
I just checked the Classic absorb timer and it has 1:45 left. I set the minimum at 1 hr this morning and the maximum at 7:30. Based on the timer and the fact that it's been in absorb for 1:45 so far today the Classic is apparently planning a 3:30 absorb time. Based on my settings I can't figure out why. I then bumped up the minimum to 4 hrs and the max to 8:30 and the absorb timer didn't change.
I just reset the Classic since I'm leaving for a couple of hours and set the min. to 3 hours and the max to 8:30. I then checked the timer and it was counting down from 5 hours. So I accomplished what I wanted which was to keep it in absorb while I am gone but why did the timer then go to 5 hours when that wasn't either of my settings after I reset the unit?
Not sure exactly how it is set but when you reset or force bulk from the tweaks menu, the timer should be filled with the minimum absorb time and
if it is in bulk at that time, the timer should count up towards maximum.
5 hours is inbetween 3 hours and 8:30 hours. 5 hours would be 3 hours plus 2 hours. Maybe it was bulking for 2 hours when you saw the 5 hours on the timer ??
When the new software comes out, the typical situation will just be to start at the maximum absorb time and spend no longer than that
in actual absorb. It will only count down to zero while the battery voltage is sitting at the absorb set point voltage.
If you still want it to do sort of what it is doing now, it will be able to do that, but be a bit smarter and not just count UP towards the
higher time value UNLESS a minimum amount of battery current and some set voltage below the absorb voltage set point (or lower)
is satisfied. This will keep the timer from adding extra absorb time when the battery voltage is very near the absorb set point
but not quite there because of either large loads or cloudy day or combination of both.
The REAL way to end the absorb time is of course to watch the current INTO the battery terminals while its voltage is at the
absorb voltage. That will be available when the networked battery monitor is used. Coming up.
boB
Quote from: boB
The REAL way to end the absorb time is of course to watch the current INTO the battery terminals while its voltage is at the
absorb voltage. That will be available when the networked battery monitor is used. Coming up.
boB
Oh, you dogs! Just had to make one more piece of nifty indispensable equipment long overdue in the off grid market. Someday, we'll look back and laugh at all those arguments about how many hours to spend in absorb. I will be a very early adopter of this thing when it comes out!
Quote from: boB on September 24, 2012, 09:56:45 PM
If it is in bulk, it counts up towards the max absorb time and THEN counts down to 0 from that time
when it finally gets to absorb.
I've been trying to follow this discussion, but still not sure I understand :D
Does this mean that the "maximum absorb time" setting, actually means "maximum time for (bulk + absorb)" ?
Quote from: stephendv on October 02, 2012, 08:05:32 AM
Quote from: boB on September 24, 2012, 09:56:45 PM
If it is in bulk, it counts up towards the max absorb time and THEN counts down to 0 from that time
when it finally gets to absorb.
I've been trying to follow this discussion, but still not sure I understand :D
Does this mean that the "maximum absorb time" setting, actually means "maximum time for (bulk + absorb)" ?
Well, hang on to your hat, Stephen ! We're about to make it a bit more complicated but at the
same time either easier OR better, depending on which method you choose to use to determine
Absorb time.
New software coming up soon with the VariMax feature EXCEPT that it will be simple and VariMax
disabled by default...
Instead of going over it again, here is what I typed up on the NAWS forum not too long ago...
http://www.wind-sun.com/ForumVB/showthread.php?17101-Rolls-Surrette-absorption-time/page3
Quoting myself from that page....
Well, when I say "much better", I mean that feature can be made to work better but still not nearly as good as a real battery current monitor to tell
the CC to go from absorb to float. This is just an option but I believe there is merit for it. I call it VariMax and will be an option in
the next version of Classic code. The up-count timer will be disabled by default but I couldn't just remove that old method completely !
The idea is to let the absorb time increase when bulk time increases ONLY if the battery current when in bulk is above some adjustable preset
value ~AND~ the battery voltage is below the absorb setpoint by an adjustable preset voltage, THEN the counter can count up.
Otherwise, the timer will just stop accumulating absorb time when the battery voltage is not sitting at the absorb voltage.
By default, the current would be higher than the CC can ever put out, (say, 101 amps), and that disables the up-count of the absorb time.
Then, the absorb time will just be a preset time like 2 hours. Of course, when the battery voltage is below the absorb set-point voltage,
the counter will stop counting down towards zero which it needs to do. The battery voltage should be held at that absorb voltage in order
to count as actually being in the absorb charge stage. This VariMax method can even be improved some more but this should be good
enough I think.
I hope this doesn't confuse people too much but I think it's an OK way to keep that feature but also can help keep batteries from
boiling away unnecessarily when the power production is iffy. VariMax may also keep the counter from counting up to maximum
in the morning just because there isn't enough sun power to really be called "bulk" charging with such little available power/current.
boB
Thanks bob, looking forward to the next firmware release!
In the meantime, I've increase the "maximum absorb time" limit to 7 hours to account for bulk phase too.
So, regarding EA on one Classic;
Had switched this Classic's Mode = Off for four days. Then returned to the site, and switched the Mode = On, late Thursday afternoon. Min Absorb Time=00:00, Max time=4:20, EA=14.5. Returned to the site Saturday. Bulk time was about 1:20, Absorb about 1:20. The ending current from the Log was about 27.7 A (calculated from last logged Pwr in Abs). Loads are very light.
Looks to me that this was the Absorb time=Bulk time scenario. I was hoping that setting Min time to 00:00 and setting a reasonable EA value would avoid any possibility of having A time=B time.
I had been "certain" that I had seen EA work correctly with the above settings, when doing daily recharge with an EA of 14.5 and Min Abs time=00:00.
So on Saturday, set a Min time for Absorb, Forced Bulk, and it took about three additional hours to get the EA close to the correct range as had been set for EA previously.
SSOOOooooo, I do not understand just why this is happening. Had noticed in the past, that EA did not always seem to be the Abs terminator -- seems unpredictable to me. And the bank has generally been getting undercharged on average. EA is really by far the best method for charging the banks here. If I were at this site every day, it would be NBD. But, am not. I could guess on a Abs time, and measure the SGs every time at the site, and make up any undercharging manually, or reduce time to accommodate overcharge, and so on.
BUT, what is the guaranteed method of completely disableing A=B time?? Does this require using the new FW?
What is the method to guarantee that EA is ALWAYS used, unless Max Abs time has been satisfied?
On the MX-60 EA is always dominant unless Max time satisfied, IF, Min time = 00:00, and a reasonably high EA is set. This is the way the current MX charged system always works. And this approach works wonderfully well.
Curious, Thanks, Vic
EDIT: And sorry, this msg seems a bit more strident than intended, but will just say sorry, rather than trying to edit the post. Love MN, just am confused with too little time to devote to understanding this right now. THANKS, VB
Hi Vic...
I just tried Ending Amps here. 12V battery and no other loads and Absorb was sitting around
3.0 amps. 2:00 hours Absorb time and no minimum time because I had VariMax disabled.
Anyhow, I had the EA set for 2.5 amps and it did not go to Float after quite a while.
I then brought EA up to 3.5 amps and 60 seconds later it was in Float with still an hour and 1/2 to
to from time only.
I think this is the mode you want to use.
The old method where Absorb time = Bulk time was what that was meant for and with Vari-Max
that can still happen sort of, but most people I think just want their absorb time to go for the
Absorb time they set it for. I think that gone are the days of 00 minimum and preset maximum
time in most cases. But then the EA appears to work fine too to stop the Absorb early.
In your case, was the battery voltage sitting at Absorb when the battery amps was below the
EA value ?
I would use this latest code with the VariMax mode. No, actually, I would wait until tomorrow
when we put up the newest beta code with the Follow-Me feature ! It's much cooler !
boB
Hi boB,
" -- Was CC at Absorb V and charge I below EA setting", NO.
Bulk time lasted about 1:20, Absorb time was about 1:20.
Min Abs time was 00:00, Max time was 4:20.
EA was set to 14.5 A. At the end of Abs, charge I was about 27.7 A. The last Logged Absorb power was about 1635 Watts.
EA appears to have been ignored, but logged data seems to strongly say that Bulk time had ended Absorb. EA was FAR from being met.
The CC had finished its Abs with a time of 1:20, and was in Float upon my arrival at the site. To get down to the correct Ending current for the bank, an ADDITIONAL three hours of Absorption time was required. So, IMHO, the CC did not use the EA value, and it is strongly implied that it used Absorb time = Bulk time.
That is all. We are still in A/C season here. This adds unpredictability to the required charge time.
I have gone back to Min and Max Abs time for now, BUT this may be what causes A=B time mode, I really have never known just how A=B mode is triggere,. but this is what i would love to avoid, as it requires daily attendance and monitoring of just what did happen, and often would require daily changes to Abs settings, and possibly manual Force Bulk etc. This daily attendance just does not work right now.
This batt bank is seven years old, and we have become friends. I do not want to hurt my firend. There is one lagging cell, which needs to be replaced, otherwise I would leave the CC off for a week at a time, and just recharge manually every week ... and so on.
I may need to snag an additional Classic for the residence here, so I can watch its daily cycling. The remoteness of the site with the Classics makes me want to not adopt Beta FW, at least until it has been rung out by others for a week or two -- for now, I am a late adopter.
Thanks boB & MN, Vic
Quote from: Vic on November 05, 2012, 12:30:54 PM
Hi boB,
" -- Was CC at Absorb V and charge I below EA setting", NO.
Bulk time lasted about 1:20, Absorb time was about 1:20.
Min Abs time was 00:00, Max time was 4:20.
EA was set to 14.5 A. At the end of Abs, charge I was about 27.7 A. The last Logged Absorb power was about 1635 Watts.
AHA ! I think I see the problem !
If the battery output current was 27 amps at the end of absorb, then the EA setting of 14.5 amp is set too low by at least
13 amps. The battery current must drop BELOW the EA (14.5) set point AND the battery voltage must be AT (or real close
to) the Absorb voltage... Both conditions must be met in order for the EA to end the Absorb time early.
As for max and min time, I would just find out what the EA drops down and levels out to after your friend says
that its' absorb cycle is done then maybe add just a little bit more time to allow for extra loads. THEN, if the
EA requirement can be met, your friend can go to Float and the job will be done for the day.
Personally, I think I would use the newer mode where you put in an absorb time (not minimum or maximum) using
the newest software with VMX (VariMax disabled) and then let the EA do its thing to end that time early if possible.
You will really want a battery monitor when we get ours going. That's the real way to use EA but as long as
your DC loads are small enough where you know your EA can work OK, then you should be fine now.
boB
OK, Ryan set me straight on what you were asking...
If you do not want the Absorb time to just go only as long as the Bulk time did,
set the MINIMUM absorb time to the shortest amount of time you want it go
go for.
The Absorb counter STARTS at your minimum absorb time and counts UP until it
reaches the Absorb voltage and then starts counting down to zero (0) time and
that is why it is absorbing for as long as it is bulking... But usually the bulk
time will be longer because there is less power available earlier in the day and
it will just count up for quite a while the way the old software worked.
boB
Hi bob, (Ryan),
Well for the systems here EA on the CC is fine, and really the ONLY way to reliably recharge these banks. Both of these systems have used MX-60s since inception. The most remote system has had the MX replaced by two Classics a number of months ago.
The EA function on the MX worked very well. EA on system 1 is set to 16 Amps EA, as there are, on average somewhat more loads on this system. This is the setting that fully recharges the battery every day. The SGs are just where they need to be.
The remote site with two Classics also needs to use CC EA as the terminator of Absorb. Its ideal setting is 14.5 Amps. With generally light, but variable loads, EA is really essential, unless one wants to change the Abs time every day or two, and I cannot do that.
On the MX-60, the ABSOLUTE way to use EA, to the exclusion of all else, other than Max Abs time, was to Set Min time to 00:00, Max time longer than one believes the bank would ever need, and then the MX would always use CC EA to end Abs. This is the way that the banks were always recharged when using the MX CC. Due to widly varying loads CC EA does work quite well.
I will admit that it can require load shedding as manually monitored actual battery charge current begins to approach the correct value, and so on.
YES, a real Bat Mon mated with the Classic CC would be better.
I had thought that I had seen EA work, but it may have just been a coincidence that it happened to be about the correct CC charge current, when the time combo timed-out ...
I HAVE guessed the correct time parameters of this system to get the bank fully charged on a few days in the past. BUT, I DO need a CC EA function. It can be from an MX, until things settle out. It is really the only way that these banks really get fully charged, with very little overcharge. And if over/undercharge is noted, then EA gets tweaked a bit, as SGs get monitored frequently.
OK, BUT, as I read it, there may not be any way for EA to be the Abs termination with the 6-29-12 FW (?). As I read your post boB, seems that there will always be the interaction on Min time and what Bulk time happened to be on a given day, even if Min was 00:00, and there was a reasonable EA value set?? If that is the case, EA would seem to be a don't care.
SRI to be ssooooo tedious. Thanks, Vic
I believe that the problem in your scenario is that you have minimum absorb time set too low.
Set minimum and maximum to a high amount of time and let the EA do the ending of absorb.
Try it on your home system and see if that doesn't work. It may be that 6-29-2012 did not
work correctly ?? Now I better go look...
OK, looking...
Looks like 6-29-2012 code should be good for EA.
You can verify that EA is working by setting the EA to something above whatever amps your Classic
is putting out in Absorb (with more time to go on the counter) and see if it goes to Float after
one (1) minute. I would set it around 1/2 amp above just to make sure the Classic doesn't see
some amp-jitter.
boB
OK Thanks boB,
The home system is charged by the MX-60, so I cannot try this just now.
Certainly, the MX seems to require Min time = 00:00. It has been my feeling that is the 00:00 setting for Min that tells the MX to use EA.
Of course, the MX has nothing to do with the Classic's EA function.
Will try it within a few days. Some of my misunderstanding is that in the case that you describe, then, Min Time is not Min Time, but is NOT ignored by the Classic, I guess.
I do hope that EA will be dominant, where Absorb is terminated ONLY by EA, or Max Abs Time, and ignore Min time, and have nothing whatsoever to do with Bulk time for the present charge cycle.
Thnak you very much, Vic
Quote from: boB on November 05, 2012, 05:48:06 PM
I believe that the problem in your scenario is that you have minimum absorb time set too low.
Set minimum and maximum to a high amount of time and let the EA do the ending of absorb.
boB
OK, Thanks boB. Was at the site a few days ago. Tried your suggestion, and the approach of increasing Abs time higher than the EXPECTED time required to reach the EA value SEEMED to allow EA to WORK OK.
But, just to try to be clear;
It would be very advantageous to me, to have a way to set EA which completely IGNORES ANY Abs TIME SETTING, or a way to set EA that ONLY LOOKS AT Max Abs time.
To me, having to guess how much time JUST MIGHT BE REQUIRED to reach EA seems to have little or nothing to do with the Ending Current into the bank. From years of experience with the friendly banks here, EA is THE best way to end Abs. If that EA value is never reached, then the bank did not reach full charge, and the amount of time it took for the bank to not become fully recharged is of no consequence (to me). And the need to guess a time that will always exceed time required time is something that seems to me to just get in the way. EA in my situation of variable, but light loads much of the time dictates that EA is the best approach, to the exclusion of ALL else. Absorption time, for me, ideally should have nothing to do with the function of EA. Having EA OR Max Abs time setting terminate Abs is OK, but Max time is not necessary (IMHO) ... but I'll take EA OR Max Abs time (setting).
While I am not a control freak, I would love to feel that I have control over the way EA behaves, and it appears that there is a time variable (Min Time) that has the unpredictable variable of the amount of time spent in Bulk.
The fact that a Min time setting will always have Bulk time added to it also makes testing less predictable, because when the CC is in Float, and one wants to SEE how the CC behaves during the transition from Abs to Float by Forcing Bulk, the Bulk time of often a minute or two, and this is bound to change the Min time from the way it was when the inital charge cycle of that day. This seems to make it impossible for one do duplicate just WHAT FUNCTION actually did terminate Abs on the initial charge for the day.
Done belaboring the point for now. Thanks! Vic
Quote from: Vic on November 10, 2012, 03:02:03 PM
It would be very advantageous to me, to have a way to set EA which completely IGNORES ANY Abs TIME SETTING, or a way to set EA that ONLY LOOKS AT Max Abs time.
You can make EA be the only thing that makes it go to Float by setting the Absorb time to the highest it will go which
I think is around 18 hours. Then, EA will be the only thing that makes it go to Float.
EA does ignore absorb time. EA does not "look" at any timers at all. If EA is satisfied, (60 or 90 seconds), it forces
a Float from absorb. Time has nothing to do with that unless absorb time is set too short. I thought you wanted
absorb time to force a float in case EA wasn't going to work.
So, I would say that you want to set the minimum and maximum absorb time REAL long... If you have the latest
software, don't even use the minimum absorb time.... Just absorb time which is what is available if VMX is not
enabled. If the older software before VariMax, just set minimum and maximum to a very long long time like
17 or 18 hours and then EA will be what forces it to go to Float.
boB
Hey Vic,
Don't worry with Min and Max Time, on mine mini is set to 30mn and max to 4hr. EA value always stop absorb.
I've added 1.1kw to my 2.1kw array two days ago, and I've noticed that my end current is now 2A higher than it was with my 830AH/48V bank this summer (7.6A). I don't understand exactly why, maybe someone has an idea.
For now my EA is 9.6A + loads and it works fine with the 6-29-12 FW.
Try to set it to 30mn Min and 6hr Max or more, it should work. Time has nothing to do with EA.
Good luck,
Erik
Hi boB, Erik,
OK boB, will increase the Min and Max times during the next site visit and see how we do.
Air Conditioning season ended last week, so that part of variable loads is done for this year, which will help things.
Eirk, often, as short Bulk and Absorb does the trick, but at times, with greater DOD, Absorb = Bulk time will yield a too short Abs, as will Min Abs time + Bulk time, but will increase min and max times, and monitor results.
Thanks for the info. Vic
Hi Vic,
From what I understand, your problem could only come from a very little DOD every day. It can't come from Max time because EA would stop your Absorb before max time is reached if set to 6hr or more.
In your case, Min time could be a problem if your bateries are near full every day. I don't think 0 mn is a good min time value for you maybe 30mn/1hr could work better. But if you want to be sure EA will be the only way to control the absorb, why don't you set your time to Min time/5hr58 and Max time 6hr ??? ? This way, you'd be sure only EA could stop your Absorb.
Try it, you have nothing to loose. Hope this help.
Good luck,
Erik
Hi Erik,
Sorry, had thought that I'd replied to this ...
The ONLY reason that had been using 00:00 Min Time, is that this is what was required on the MX-60 for it to use EA OR Max time. Had guessed that this would also be the case for the Classic, given the genes in each of these CCs. And, guess that am hung up on how important TIME is, vs Current. When EA works, the time is not relevant to me -- Min or Max, but I will take Max time if forced to, and Min almost = to Max should be fine, guess ...
Thanks, Vic
Quote from: Vic on December 04, 2012, 04:07:46 PM
Hi Erik,
Sorry, had thought that I'd replied to this ...
The ONLY reason that had been using 00:00 Min Time, is that this is what was required on the MX-60 for it to use EA OR Max time. Had guessed that this would also be the case for the Classic, given the genes in each of these CCs. And, guess that am hung up on how important TIME is, vs Current. When EA works, the time is not relevant to me -- Min or Max, but I will take Max time if forced to, and Min almost = to Max should be fine, guess ...
Thanks, Vic
Ahhhh.... Consternation, turned to lucidation !
Excellent, Vic.
Glad you got it now.
boB
Hi boB,
Yea thought I got it some time ago, but today did see something curious ...
Went to the remote site with Classic CCs today.
Was surprised to find the single Classic that does all the charging in Float at about 10:30 AM. Mostly cloudy day.
Looking at the Log, see Bulk Power levels slowly ramping up then remaining around 585 Watts -- about 11-12 A on this 48 V system. Noted that at 10:11 AM, CC was delivering 583 Watts, then at 10:21, the CC was in Float, delivering 87 W. No recorded Absorption stage ...
There were 1.6 Kwh delivered today at time of arrival, rough normal amount is about 2.1 Kwh, although this does vary, primarily due to run time of a small 120 VAC referigerator.
Running the 6/29/12 FW for both the Classic and MNGP.
Min TIme 2:44, Max Time 4:20, EA 16.1A.
Looking at the SGs, the bank was mostly charged, so looks like the Bulk was good, just needed an Absorption.
Have there been any changes to the way Max, and Min Times work, or how EA functions between this older FW and the present Production FW?
Before leaving the site, set EA to 00:00 or 00:01 -- whatever is the lowest, and set Min Time to about 1:30, Max 1:31 which are probably too long. Will need to return tomorrow to try to guess a new time.
Guess that due to the high SOC at the start of today's charge (and on almost all other days as well), that the slow lowish average current Bulk eventually got to Absorb, and Absorb current was below EA, so went to Float essentially instantly ... ???
So, what am I doing wrong? Had expected that the Classic would do the Absorb, because believe it finished the Bulk, would expect that EA would NOT be satisfied in this situation, as charge current never exceeded EA.
Thanks, Vic
Quote from: Vic on December 04, 2012, 06:35:58 PM
Guess that due to the high SOC at the start of today's charge (and on almost all other days as well), that the slow lowish average current Bulk eventually got to Absorb, and Absorb current was below EA, so went to Float essentially instantly ... ???
So, what am I doing wrong? Had expected that the Classic would do the Absorb, because believe it finished the Bulk, would expect that EA would NOT be satisfied in this situation, as charge current never exceeded EA.
Thanks, Vic
The first (top) sentence I understand. That makes sense. When the voltage is at absorb and the current is LESS THAN the EQ setting,
then it will go to Float early.
The second sentence I don't understand... " EA would NOT be satisfied in this situation, as charge current never
exceeded EA"
When the voltage is at absorb and the current is LESS THAN the EQ setting, then it will go to Float early.
There has been a very slight change regarding the latest firmware or two regarding this and for good reason, mainly having
to do with when using multiple charging sources...
That is, the minimum EA setting now goes to zero (0.0) amps... This is actually "DISABLED"....
Problem before was that IF another classic (or any charging source) is holding the battery at or above Absorb voltage,
then the OTHER Classic will NOT be outputting much or any current BUT it will be at Absorb voltage and that will
satisfy EA requirements ! That is a no-no because that Classic isn't doing ANY work, possibly.
So if that OTHER classic sees the voltage at Absorb and its current is reading 0.0 amps, that is less than 0.1 amps.
If you have two or more Classics networked with Follow-Me in the system, the OTHER Classic, with amps less than
EA setting and seeing the voltage at Absorb would go to Float and take the Classic to Float with it.
Thanks to Chris Olson for finding that one.
So, now, 0.0 amps is a special case which actually disables going to Float when those parameters are satisfied.
I am surprised that the MX60 did not show this problem, at least while I was working on it.
boB
Hi boB,
Thanks,
Regarding the MX-60, it may show this same issue, BUT the MX-60 charged system experiences greater DOD, and has about 60% of the PV that the system that I described above, so today the MX-60 charged system dragged along in Bulk all day, almost made it to Absorb but did not get there.
In considering the situation with the Classic charged system, it is NBD, really. The bank got mostly charged. And, probably will not get fully charged tomorrow, BUT it might, as the bank will need more charge tomorrow, which will be another dark day, so may spend some time in Abosrb. NBD. This system really needs to be recharged once in 3-4 days due to its light useage. The main issue to me is the lack of my understanding of just how the charge cycle works. Have spent many years watching the MXed bank charge, but its nature is different due to SOC and PVi input, so, my expecation is not meeting reality.
However, there is an extension of this same issue -- the direction from which EA is approached. The Classiced system had EA approached from below -- a current less than the EA setting. The fact that this lower than EA current (eventhough the charge current was NEVER above the EA setting) satisfies EA and causes transition to Float is the same thing that makes ReBulk NOT WORK from Float in most situations. If one wanted to RB from Float, one would need to create some substantial loads on the system, such that the output current from the Classic is greater than the EA setting. If this is not done, it appears that RB does NOT work, because it spends milliseconds or less in Bulk when trying to do a RB, because EA has been satisfied perhaps before the Classic even tries.
This, too, is NBD, but if the Classic was sensitive to the direction from which the EA value was approached, RB would do its intended function, as would the Bulk-Float transition noted above.
This RB issue is the same in the MX. It appears to the system operator that RB does NOT work. But in reality, it does not work when a reasonable EA value is set, when in Float, with light loads on the inverters. Again, NBD. I did not know why RB on the MX-60 did not appear to work for years, years and years, until stumbled onto it with the Classic.
No wonder it takes a long time to get complex real-time control systems like the Classic into the market. And this is just one micro small thing, of which there are thousands and thousands for you folks to figure out and make work.
Thanks, yammering almost done. Vic
Quote
Guess that due to the high SOC at the start of today's charge (and on almost all other days as well), that the slow lowish average current Bulk eventually got to Absorb, and Absorb current was below EA, so went to Float essentially instantly ... ???
Just trying to get my head around how this could be a real issue if at all.
My system has low DOD weekdays and I have my EA set to end my absorb and trigger float. Through experimenting with a a very low EA setting (1A) and watching my pack at the same time knowing my loads. I have found a EA setting (16.5A) it works well for my pack. I have used this setting for the past 30 days and its been very reliable.
My understanding of the issue described in the quote above is.
Say my classic charger managed to reach absorb voltage and enters absorb but at the time it reached absorb the maximum available output of the PV was less than 16.5A due to very dark/cloudy conditions that the End amp criteria would be met and I would go to float even though the battery has spend little time at absorb.
My thinking of what saves this from actually happening in reality is 16.5A wouldn't not be enough amperage to hold my battery's at 60V ( my packs absorb voltage) for the required 60 -90 seconds to trigger EA. Instead it would trigger back to (bulk) due to voltage dropping under 60v.
Due to the nature of how battery's work. The only time 16.5A is enough amps to hold the pack at 60v is when the pack is 100% SOC so its fine to go to float if it dose.
I don't so how end amps could be triggered when the pack is not full unless you have a way to high end amps setting say 25A for me instead of 16.5A
I could be wrong or missing something :-\
Kurt
Quote from: offgridQLD on December 04, 2012, 11:57:41 PM
Quote
Guess that due to the high SOC at the start of today's charge (and on almost all other days as well), that the slow lowish average current Bulk eventually got to Absorb, and Absorb current was below EA, so went to Float essentially instantly ... ???
Just trying to get my head around how this could be a real issue if at all.
My system has low DOD weekdays and I have my EA set to end my absorb and trigger float. Through experimenting with a a very low EA setting (1A) and watching my pack at the same time knowing my loads. I have found a EA setting (16.5A) it works well for my pack. I have used this setting for the past 30 days and its been very reliable.
My understanding of the issue described in the quote above is.
Say my classic charger managed to reach absorb voltage and enters absorb but at the time it reached absorb the maximum available output of the PV was less than 16.5A due to very dark/cloudy conditions that the End amp criteria would be met and I would go to float even though the battery has spend little time at absorb.
My thinking of what saves this from actually happening in reality is 16.5A wouldn't not be enough amperage to hold my battery's at 60V ( my packs absorb voltage) for the required 60 -90 seconds to trigger EA. Instead it would trigger back to (bulk) due to voltage dropping under 60v.
Due to the nature of how battery's work. The only time 16.5A is enough amps to hold the pack at 60v is when the pack is 100% SOC so its fine to go to float if it dose.
I don't so how end amps could be triggered when the pack is not full unless you have a way to high end amps setting say 25A for me instead of 16.5A
I could be wrong or missing something :-\
Kurt
There is no problem or trickery here. If it takes less than the EA setting to keep the batteries at the Absorb voltage, then the batteries are full.
It doesn't matter if the current comes up from below EA while the voltage rises to Absorb or if the current comes down from above EA while the voltage rises to reach Absorb.
In the first case, where the current and voltage is rising, the batteries were likely almost full already and the available power was low to start with (clouds or whatever)... In the second case where the current is falling and voltage is rising, the batteries probably needed a full charge and there was plenty of power/energy to charge the batteries.
As long as the EA setting is correct for the DC loads on the system, it works fine.
When using EA to end the Absorb and go to Float, it will work as long as the DC loads on the battery are not higher than expected. Even if the loads are higher, it is OK as long as the Absorb time isn't way too long. If this high DC load issue happens only once in a while, then that's great.
boB
QuoteWhen using EA to end the Absorb and go to Float, it will work as long as the DC loads on the battery are not higher than expected. Even if the loads are higher, it is OK as long as the Absorb time isn't way too long. If this high DC load issue happens only once in a while, then that's great.
Great that's just how I was thinking it was.
The only time I have seen a issue switching to float with EA is like you say unexpected large DC loads.
I remember one morning i was watching the remote software I could see the amps dropping of below the EA trigger point. My wife at the same time started doing the dishes (obsessed with rinsing every single cup spoon and knife individually) Making the 500w pressure pump cycle on and off every 20 seconds as she rinsed >:(. A simple request from me to stop rinsing for 90 seconds and the classic then had a 90 second window of base loads to trigger end amps and switch to float.
95% of time there is a small 90 second or more window of time where things settle back to predictable base loads and EA works fine. :)
Kurt
Quote from: offgridQLD on December 05, 2012, 01:04:49 AM
QuoteWhen using EA to end the Absorb and go to Float, it will work as long as the DC loads on the battery are not higher than expected. Even if the loads are higher, it is OK as long as the Absorb time isn't way too long. If this high DC load issue happens only once in a while, then that's great.
A simple request from me to stop rinsing for 90 seconds and the classic then had a 90 second window of base loads to trigger end amps and switch to float.
HAHA ! That's great ! I can just see you telling her to stop washing the dishes while you wait and watch your CC go to Float !
Thanks for that one, Kurt !
boB
Well, before posting any of this Bulk-Float observation, did reflect on it for some number of hours.
In the seven years of watching these two system manage recharge each one using EA as the terminator, just have never, ever seen the above behavior - not ever.
There is a camp of folks who believe that a FULL recharge requires a certain time being spent with the charge voltage being held at a reasonable Absorption V. I am in this camp. The Absorption stage is noted as finishing the last 10-15% of the recharge, and is important in helping mix the electrolyte in FLA banks.
The recharge cycle noted above appeared to be just a small bit short of full, but the numbers are quite small, and it is difficult to measure small SG differences, but from experience, the bank looked slightly undercharged.
With larger banks, is becomes easier to notice effects of discharges and charges from several prior days. I was simply unable to access the previous day's Log data via the MNGP ... it simply would not display. Do not use the App to display logged data, as there is no computer at this site. Had wondered if the previous day or two, the bank was a bit overcharged, perhaps allowing the bank V in Bulk to rise to Vabs at a lower-than-normal current ... the date/time data is correct ... dunno.
On the flip side of believing that perhaps the EA value needs to have been exceeded in order for EA to end Absorb, realize that on days of low solar power availability, one can grind along all day in Bulk, almost reaching Vabs, but not quite, and this can really overcharge the bank.
But, still, believe that the set EA value should really be exceeded during the charge cycle for a given day, in order for EA to terminate Absorb. This would could also allow ReBulk to work when the CC is in Float with light loads (current delivered by the CC below the EA setting), and as of now RB does nothing in the above situation when EA is "enabled" -- it appears that RB command was totally ignored.
And so on. This is NBD, just something that have not ever seen with the venerable MX CCs. Using CC EA is always a compromise, as varying loads do affect the real charge current delivered INTO the battery bank. But batteries are teriffic integrators, and all that is needed for battery health is the average recharge, not just one on a single day. Thanks, Vic
Quoteis important in helping mix the electrolyte in FLA banks
I was under the impression EQ would get this mixing done.
On a weekday when my bank is usually only 95% SOC in the morning. Due to very light overnight consumption. I see 1hr or so at bulk returning around 2.5kwh or so into the battery then I hit absorb voltage 60v and I'm usually pumping 30A into the pack at the start of absorb but it take little time perhaps 1hr for the amps into the battery to drop to the 16.5A EA setting triggering float.
I feel the battery is getting 100% charged but the question of electricity stirring- gassing due to being held at a high absorb voltage for a particular length of time its beyond me :-* 1hr of electrolyte mixing at absorb voltage or say 2 or 3hrs mixing i haven't ever seen any study's to determine the difference. i do know they get a good mix up when you do a EQ.
Factory specs for absorb on my battery's is reasonably high at (60v) so they do get some mild gassing - stirring during the absorb even if it is only for 1hr or so.
Kurt
Hi Kurt,
Well, I did not mean to say or imply that the Absorption stage was soley to mix the electrolyte, but the gassing during Absorb does mix the electrolyte, and it is an important function that ocurrs during that last part of a charge cycle.
EQ is a very active mixer, but is usually done infrequently (if one is lucky).
Thanks, Vic
Vic, I think I know what you want added to normal old Ending Amps method of operation...
When the battery voltage rises to the absorb voltage and the battery current is already
under the EA setting like in your post, below, you would like it to take longer than
60 or 90 seconds. THAT would be your MINIMUM absorb time. Am I right ???
To my knowledge, there should not be any more time required in absorb as long as
the current that it takes to be AT the absorb voltage is below the EA setting, but I
understand what you are talking about I'm pretty sure.
Not a bad idea really. Just not sure if it's absolutely necessary.
Who knows ? It might even get in there at some point.
Thanks for the idea.
BTW, today I tested the EA along with the ReBulk and they both appear to
work fine. Remember that the ReBulk will not take effect in Float but will
require the CC to be in "FLOAT MPPT" with the battery voltage below the
actual Float set point.
Or, maybe you meant something else instead ??
boB
Quote from: boB on December 06, 2012, 03:30:09 AM
Vic, I think I know what you want added to normal old Ending Amps method of operation...
When the battery voltage rises to the absorb voltage and the battery current is already
under the EA setting like in your post, below, you would like it to take longer than
60 or 90 seconds. THAT would be your MINIMUM absorb time. Am I right ???
To my knowledge, there should not be any more time required in absorb as long as
the current that it takes to be AT the absorb voltage is below the EA setting, but I
understand what you are talking about I'm pretty sure.
Not a bad idea really. Just not sure if it's absolutely necessary.
BTW, today I tested the EA along with the ReBulk and they both appear to
work fine. Remember that the ReBulk will not take effect in Float but will
require the CC to be in "FLOAT MPPT" with the battery voltage below the
actual Float set point.
boB
Hi Bob, Thanks for thinking about and considering the low current EA situation.
Agree, I would like to see much more time than 60-90 seconds spent in Absorb in this situation. Min Absorb setting should be Fine. And, also agree that it is not absolutely necessary. Daily full recharge is not necessary. But, when there are a number of days in a row with fairly low PV (or other RE) power input, it may be helpful to get some real Absorb time for the batteries. The situation with this bank is not too common, so am not asking for you to build something just for my situation.
Regarding Re-Bulk when EA is ENABLED, with the 6-29-12 FW, RB seems to work like I'd like to see it work -- from Float --, only when current delivered by the CC exceeds the EA setting. This is from Float, not FloatMPPT.
While, I am not a real Control Freak, I would like RB to do a real RB when I ask the CC to do it. This is often done when one is trying to see just how something does work, or that something resulted in the battery not being fully charged, and one needs to take another shot at it on a given day. If the initial Bulk had been done, the Bulk part of RB will only last a few minutes, and not harm the bank by beating on it too hard in a single day.
To me, even if EA is enabled, and one asks the CC to RB, I'd like to see the CC do a RB from Float, even if the CC output current is well below the EA setting. When there is ample PV input, if only the CC would TRY to do the RB, the current would rise well above the EA setting, and all would be well.
Regarding RB working from Float-MPPT, seems to me at that point, an RB is moot, as there is not enough current available to even maintain Vfloat, is it not??
It is true that there are several ways to cause another Bulk/Absorb for example, sertting Vfloat to the desired Absorption V, but then it is up to the operator to terminate this new cycle, by resetting Vfloat to the real desired V. And there is always shutting off the PV and Batt breakers, and re-powering IIRC, and think that there is another way that you may have described which creates a second Solar Day on the same date ... But, to me RB should DO an RB when requested by the user, and doing it from Float would be good. I CAN turn on some heaters to get the CC output I above the EA setting, and, am certain that this has worked with the older 6-29 FW, from Float with less than EA current.
Another NBD thing, but to me as it is, when using EA, RB just appears to NOT work. (I had felt the RB on the OB MX-60 simply was broken, as have never seen the MX RB, probably since I always use EA on those, too).
OK, enough, THANKS! None of this stuff is to get too wound up over, just little things. Vic K6IC
This opinion is from someone who is still very much a rookie in the world of all things associated with batteries, charging, solar and off grid. But I am a fast learner and climbing my learning curve as fast as I can.
Everything that Vic posted is what I assumed was the way it worked when I started trying to learn/program the charge parameters on the CC.
ReBulk: If I (or anyone) goes into the menu and manually ask for a Re-Bulk, that is what should happen. At that point the operator is taking over from the logic/algorithims, or any programing in the CC. One would only go to that menu and do a rebulk for a specific reason; to put more juice into the batteries... now. The owner/operator does though have to take on and accept the responsibility to monitor and turn off the manual Re-Bulk.
On the EA front I am leaning towards Vic's thought process here but because I am so new I am not as versed as he is. I do know that when I have a number of days with light use the voltage rises quickly and I am not in absorb very long (EA met) but when the SG is measured the batteries are a little on the low side. This is where I think there would be a benefit to getting more than a couple minutes of Absorb.
You are confusing ReBulk with Force Bulk. If you Force Bulk manually that's exactly what happens the CC starts a new Bulk charge algorithm. ReBulk is an automated way to do this. It is a battery voltage lower than float. What happens is if the cc goes to float and a load or clouds intervene and the battery voltage drops to or below the ReBulk setpoint the cc will start a new bulk charge.
Ryan
That is why I wrote the first sentence in my post. :-[
I guess I got confused when Vic talks about "To me, even if EA is enabled, and one asks the CC to RB, I'd like to see the CC do a RB from Float, even if the CC output current is well below the EA setting." I guess I am not sure what this is then....
And the learning continues.
If the ReBulk set point voltage is at or above the Float voltage, then there is no reason to have a Float voltage.
Set the Float voltage above the ReBulk voltage in that case.
The Float voltage must be at least one tenth (0.1) volt below the Absorb voltage. Normally they will be quite
a bit more different than this.
Making the EA time be variable is a possibility here though.
boB
Quote from: Halfcrazy on December 07, 2012, 01:47:21 PM
You are confusing ReBulk with Force Bulk. If you Force Bulk manually that's exactly what happens the CC starts a new Bulk charge algorithm.
Just lost a post ... otra vez ...
Ryan, YES, you are absolutely correct.
While I DO know how ReBulk works, I WAS definitely using the WRONG term for the command that I was referencing.
So, First am very sorry to go on and on, whining about something while using the wrong term for the command.
SO, was referring to the command in the Tweaks menu called Force Bulk.
Speaking of Force Bulk -- FB --, it is this command that appears to be sensitive to EA being enabled, and when in Float with CC output currents below the current setting for EA that the CC appears to ignore the FB command. It must be that the CC does not even try to start a new Bulk, because if it did, in almost all situations, the CC output current would rise well above the EA value when there is reasonable sun available. It appears that the Force Bulk command is just ignored. Assume that perhaps the FW looks for an EA value, and if this is satisfied, the new Bulk is not begun - guessing of course. Could also be that the new Bulk is started but the FW notes that the CC current is at/below the EA value, although one might think that there would be the 60-90 second dwell time ... and so on. Dunno.
SORRY for using the wrong term, and wasting valuable mental bandwidth of Forum members and MN Engineering and Tech.
Thank You for the help, Vic