Hello guys,
First post on this forum.
Could someone tell me if the End Absorb issue has been fixed, or if it will be fix only in the next firmware?
Thanks,
Erik
Hi Erik,
I am just a Classic user. I've seen nothing regarding enabling the EA function.
The last FW posted on the MN site is dated 4-29-12:
http://www.midnitesolar.com/firmware.php
It is quite possible that the EA function will be included with a major FW revision ... again, I know nothing specific. Would love to have that function, too.
Vic
Hi Vic,
Thanks for your answer.
I've seen on a post that Bob was talking to fix this problem in May.
Of course, it's not easy to manage a battery bank (830Ah @ 48VDC) with only the Absorb time and light discharge in Summer.
My BMK shows 10-15A positive every sunny day even if I set it with just 1 hour of Absorb time and steady loads (freezer and refrigerator).
Hope it's going to be fixed soon, may be Bob could tell us when he thinks that we could have this revision ;).
Erik
The EA has been fixed and will be part of the next release in hopefully, just a few days. Less than a week I'm pretty sure.
There were a few little things that needed some attention and we were waiting for those changes to be done before releasing
the next. We could have just released the fixed EA but we don't like to release lots and lots of versions if we can
help it as we need to test each one pretty thoroughly first. Bugs always seem to show themselves as the software
gets more complicated. It just seems to turn out that way.
boB
Hello Bob,
Happy to hear that this will be fix soon, I have two Classic 200 to install in the next weeks and it would be great to have EA and Time in order to be sure my custommers not overcharge a little every day.
I understand that you could not release a lot of version for just a few change.
Vic, did you mount your Classic with 300VDC breakers or did you keep it under 150VOC?
It's not easy here in Quebec to find 60 or 80A 300VDC panel mount breakers, don't know why at this time my supplier just want to sell 300VDC din rail breakers. Bob, is there a reason? Personnaly, I prefer to install all Classic breakers in panel mount slots and to keep din rail slots for loads, BMK, AGS.
At least, is it safe to use two 60A 150VDC (Panel mount) to make a 300VDC breaker?
Thank for your answer.
A+,
Erik
Hi boB,
Thanks for the info on the EA update. Boy, as an end-user, I prefer to have somewhat fewer updates. Have a Hammie Radio, where there was an update every few days or so, and it was almost impossible to keep up. AND, it kinna made the radio appear a bit "unstable". So think that you are doing the correct thing, not even counting the need for you folks to do all the testing on a new rev.
Erik, you are a true Musher -- 50 dogs in waiting.
On the Voc, have not done any system with Voc over 140-ish V at this point, so 150 VDC breakers have been fine. Agree, I prefer the Panel Mounts over the DIN Rails for CC PVin and Batt breakers.
Here in USA, the HomeBrewed 300 V breaker from two 150 volters, ganged would not fly technically, but may work well. Bet Robin has thoughts on that. Altho, many AHJs miss the fine detail, but that is a crap shoot on what one AHJ might notice.
Anyway thanks boB, for the info on EA, am charging the lap-top now! Vic
Hi Vic,
In the past we had up to 90 sled dogs around the cottage, we lived off grid far north ten hour from Montreal. It was great! We had to drill hole with chainsaw two feet width in the ice to have water in winter. I bought my first solar panel and pump at this time... ;D
With an old Trace DR we were able to run a few appliances and tools, it was heaven...
Thanks guys
A+,
Erik
Erik. Vic, boB
I too get (+) positive amps on the BMK everyday. They seem "hollow" because as soon as the sun goes down, the BMK very quickly goes to 100% then slowly starts it's nightly drop. I never really understood what is going on...
So, when we get the new release with EA, is the game plan to watch the BMK hit 100% and check the SG to make sure it's up to spec. then adjust the EA to stop the absorb at that point? In theory it should work both winter and summer correct? Or is this something that need attention a couple of times a year?
BTW, I have three dog's that would piss in the house if they could when the snow fly's... Their legs are so short their junk drags and I kind'a see their point though...LOL (Two Chihuahua's and a JRT)
Regarding Ending Amps Absorb to Float transition, just realize that the Classic does NOT know that actual current in to the battery itself as there may be other loads across the battery taking current from the Classic.
I Love the dogs !
boB
I was thinking about this the other day. Seems End Amps is not a very useful measurement for anyone who is powering any sort of house with variable loads off grid. Yet it also seems that End Amps is a better way to determine the end of an Absorb cycle than voltage.
I know the list of requested improvements is never ending, but wouldn't it be a relatively simple thing to have a charge controller look at a shunt across the main bus and compare that amp reading to the charging amps to determine actual end amps into the battery?
Hi Guys,
Totally agree with VolvoFarmer. Of course, EA is not perfect but it could help to be more accurate, it couldn't be worst than just using a fixed Absorb time (1 or 2hr) in summer.
Paul, in Summer you could try to lower your Absorb to 57.6/58.4, 1 1/2hr (check your SG) and set it to 58.8/59.2 2hr-2 1/2hr for automn/winter.
Bob and Paul, if you like dogs and need a breath of fresh air take a look at : http://www.chiensdetraineauquebec.com/commun/album/Baie_James/index.html
A+,
Erik
Quote from: Volvo Farmer on June 27, 2012, 08:22:29 AMbut wouldn't it be a relatively simple thing to have a charge controller look at a shunt across the main bus and compare that amp reading to the charging amps to determine actual end amps into the battery?
I have no idea how simple that would be. FWIW, Outback systems can do that. I think I read somewhere on this forum that Midnite plans to do this also. --vtMaps
Quote from: SolarMusher on June 26, 2012, 07:55:16 AM
At least, is it safe to use two 60A 150VDC (Panel mount) to make a 300VDC breaker?
You mean wire them in series? I don't think so. They would have to trip simultaneously to be safe. In reality, one will trip before the other and would then have to interrupt the entire 300 volts. --vtMaps
Hi Erik,
Just saw this Panel Mount Breaker from MN that is available in 60 A and 80 A 300 volt sizes:
http://www.midnitesolar.com/productPhoto.php?product_ID=271&productCatName=Components - Breakers&productCat_ID=16&sortOrder=14
EDIT: OK, guess that I do ont know how to do a direct link to an individual item on the MN site, so use the above link and select " Components - Breakers " and locate this item:
MNEDC60-300, MNEDC80-300
(perhaps the link is too long ... VB)
Retails at $40 US.
And YES, vt, that was the "ganged" reference in the fifth REPLY was meaning. But, looks like MN has done it, and it is ETL listed.
Have fun Mushing, Erik. Vic
vf,
For my personal off-grid systems, use EA any time I can. And its suitability depends on the nature of the loads on the battery bank at the time where Asorb should be ending.
There are not many choices in just how to end the Asorb stage -- TIME is one, as the VOLTAGE is fixed due the the setting in charger voltage menu ... EA is the other, but the CC cannot know how much current is going into the batts, and how much is Inverter (and perhaps other) loads.
IMHO, the most problematic loads are those that are large, and run for a long time period. Also, larger battery banks are better able to deal with the effects of these loads (generally), as a larger bank responds more slowly to the CC staying in Asorb too long, resulting from a largish load causing the CC to believe that the BATTERY is accepting all of the current sent toward the batteries.
Intermittant largish loads, like an A/C or heat pump cycling is usually not a problem here, if it cycles on and off, every few minutes. A hair dryer could be a problem if it runs for 20 minutes, or so. Pumping water from a deep well into a large-ish storage tank would be a problem, as this can easily require hours of run-time of a large pump load, quite possibly causing a CC to hang in Asorb hours too long.
vt, I am certain that the OB CCs CANNOT measure an external Shunt (in the neg lead of the battery bank) directly. The EA function on Net battery charge current in the OB system, requires their Battery Monitor -- FNDC, and the correct Mate to Monitor and End the Asorb on Net charge current. Know that you know this, as you were invlolved in discussions on the OB site and one other, and you pointed out some errors in my posts -- just trying to make clear the requirement for additional hardware/FW on the OB system.
Believe that MN has made clear their plans to have a BM function in their product line in the future.
It WOULD be conceivable that a CC could have the ability to monitor an outboard shunt in the negative battery lead, allowing the CC to EA on actual Net battery charge current. Vic
Quote from: Vic on June 27, 2012, 12:13:21 PM
IMHO, the most problematic loads are those that are large, and run for a long time period.
Right ! If one had big loads that just came on once in a while, then EA could work in-between times when
those loads are off.
Erik, is that your team of dogs in that link ?? Beautiful !!
boB
LOL...I'm so frigg'n out of my league on this topic. Man, all I wann'a do is get the most out of these batteries by not going too far either way from their comfort zone. Overall, I keep all loads low to moderate and cut off the fingers of those who refuse to comply.
Not sure now which way to go, is there a simple way to decide, EA's or TIME, without having a doctorate in CC's and FLA"s :-\
Quote from: plongson on June 27, 2012, 08:09:30 PM
LOL...I'm so frigg'n out of my league on this topic. Man, all I wann'a do is get the most out of these batteries by not going too far either way from their comfort zone. Overall, I keep all loads low to moderate and cut off the fingers of those who refuse to comply.
Not sure now which way to go, is there a simple way to decide, EA's or TIME, without having a doctorate in CC's and FLA"s :-\
Time is how this has been done for many many years now instead of EA telling it to go to Float.
This is because around 2 hours is typically what it takes for the EA to come down to the right value after
the batteries have been discharged. If the batteries have not been discharged very low, then it will
take less time and that is why the EA is nice. BUT, this is why we try to Absorb for less amount of
time if it took less time for the batteries to come out of Bulk MPPT charge stage.
The problem is that early in the morning, you will have less sunlight and that means less power going into
the batteries and so the amount of time it takes for that Bulk stage is almost always longer than
it would be if you started out right in the middle of the day with full charging gusto power and current.
I have a way around this, but it will be a little while before the Classic will have this algorithm
put into practice in the real software.
So, to sum it up, it is OK for the Absorb charge stage to take longer than necessary. But in those cases
where say, 2 hours is two long because the batteries weren't all that discharged, you just have to
watch the water level to make sure they don't go dry or below the top of the battery plates.
That is normally just fine for flooded batteries... (NON- AGM/GEL batteries that is...)
P.S. It i still OK for AGM/GEL batteries to have the longer Absorb time too as long as the
temperature compensated voltage limits are adhered to. This is why there is a MAX and MINimum
Temp-Comp voltage upper and lower limit in the T-Comp menu.
boB
Thanks boB,
Great explanation and I'm getting a better understanding of how to properly keep these buggers charged. Up to now, I've been mostly obsessed with undercharging but now I see the problem with overcharging. It's a thin line but it's clearer with your help.
Paul
Hi boB,
Thank for taking time to explain how you see the Absorb process, it's clear now.
Yes, it's my dogs during an adventure trip on James Bay icefield (Waskaganish to Wemindji in Cree territory) in the north of Quebec.
Sadly, these pictures were made in 2003/2004 and I've lost most of them. If you like dogs, you know what I mean. There's nothing like sled dogs. More pictures on http://www.crocblancaventure.com/traineau-a-chiens-quebec/album.html
Thanks for your great support
A+
Erik
Paul,
I like very much your CC and FLA doctorate ;D
Just think, when we have to explain CC and FLA to our custommers who want logical thought... ::)
We all try to give our best.
A+
Erik
Regarding the 300 volt breakers/ The parts we have made for us are internally ganged to trip at the same time. If the voltage you are trying to interrupt is 200 volts or above at any sort of real current, the two individual bereakers will not work. They will weld themselves closed when attempting to pen. They must be internally ganged. I'm glad you found the 300V panel mount breakers on our wbsite. In the near future yu will als find an 80 and 100 amp din rail 150V breaker. These are in the works now. Price should be about $34.00 just like the 300V breakers. They do require additional busbars though so may cost a couple bucks more.