Simple answer and explanations

[plongson]

Is there some documentation or perhaps a .pdf covering the newer elements, Varimax , End-Amps and other CLASSIC features?

I was searching through old threads and got a bit of a clue, but one could read for hours on the subject. I'm running v1043 and plan on updating this weekend and perhaps modifying some charge parameters (or at least investigating them).

What I'd like is
1.) An explanation of what the feature is and how/why it is applied and the advantages of its use.
2.) A basic setup example.
3.) A one-stop technical white paper would be fabulous.

I know these topics have been covered in the forum but I just don't have the time to search. My schedule only allows me to focus on the system "just here and there" and it is on "autopilot" mostly. It's really running great, but I'd naturally like to optimize it if possible.

As always, we all appreciate the work you guys do and know you are probably buried with work. All one has to do is look at the support and responses in the forum to be really impressed.

THANKS!!!

Paul

Thanks

[TomW]

Paul;

I am in the same boat you are. I read most of what is here but the Classics' abilitiis  have grown and morphed over time. The documentation lags a bit.

I have not done much customization because I am confused and way behind the curve on all that this beast can do.

I suspect the Midnite guys are overwhelmed on keeping up the documentation on the ever evolving Classic. I used to write Avionics test and certification documentation and know it can be a full time job keeping up on new updates and upgrades and another full time job doing the writing.

I have just accepted the default setup so far and hope to get involved with its more involved abilities as I get more comfortable with it.

Patiently awaiting the information those hard working guys will eventually get published.

Had a nice, cool, sunny day yesterday and saw 1364 watts (93+%) of rated power from our 1500 watt array through the classic. I love it!

Tom

[plongson]

Ya, the Classic REALLY is an amazing piece of work and workmanship. Something MidNite can be very proud of. I sure could use a detailed tech manual though...

Paul

[Halfcrazy]

I do apologize I am WAY behind on the manuals. I will throw a big thank you out to Tom he has helped a ton moderating here that has made some extra time for me to work on this. I have done a video on VariMAX but never gave much thought to End amps. I do plan on a major work session very soon where I will hammer on documentation.

Thank you for the continued patience on my Slacking on the manuals. Winter is about to set in here and I will have lots of time to set by the wood stove and type and think  Of course I also decided to install Ubuntu on my laptop so now I am stretching my brain power a bit

Ryan

[Robin]

Ryan, you might want MidNite to buy you Dragon to help get the manuals updated quicker.

[SolarMusher]

Quote from: SolarMusher on November 17, 2012, 06:01:10 AM

Hi boB, Ryan,


Quote

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.



What would be a good current value to let the absorb time increase with new Varimax FW? That's what I'm not sure to understand.
Example: I have now 3.2kw PV/60A to 830AH/48V batteries (25% DOD, classic 200), could 30A (10am) be a good preset Bulk current to allow the Absorb time to increase? If not, what should be a good bulk current value to begin in this case? Of course C/10, but it's not possible to start a bulk charge on solar at full power. So what, C/5? C/2?
I understand that you want to let Absorb increase only when a minimum bulk current is avalaible and to control Absorb (fixed time) when cloudly with less current to not overcharge. But maybe you could give real math/examples/details for some of us who are not expert.
Thanks
A+
Erik



You have a 48V battery so I would bring that relative battery voltage down at least 1.0 volt... Maybe lower, like, -1.5 volts
below Absorb set point.

On the amps, it needs to be lower than what you normally get out of your system into the batteries but higher than
what you get out of the system early in the morning.  Almost anything should do, like say, 10 amps maybe ??

Maximum time is whatever time you normally want for Absorb time.
Minimum time...  If your system has the chance getting to Absorb soon because the batteries are
already charged and that normal Absorb time is too long for that situation, this is where VariMax
comes in.  In that case, just set the minimum Absorb time to something smaller than your normal
2 hours, say, 1/2 hour ?

Try that for starters.

boB

Paul,
Here is a basic set up posted by boB in "Varimax help" thread.
Erik

[plongson]

Erik, Thanks for the info!

On Saturday I loaded the latest non-beta v.1070 for the Classic. I searched all over the program and never found the Vari-Max feature, I had other issues that kept me busy. I ran a permanent Cat-5 to the router for the status panel etc.

The biggest thing kicking my butt again is the SG on these frigg'n Surrettes. I know it's winter, but damn they sure are a challenge.

When they went into float sometime in the afternoon, I had at least half that were 1.260 some at 1.250 and two were at 1.240/1.245. I did a 4 hr EQ over Thanksgiving on the genset at 64v but even then not all came up to 1.260. I did a short 1 hr EQ on Saturday as well.

I have been absorbing at 59v for 3 hrs and have very low use during the week. I bumped up the absorb to 3.5 hours/59v and hope this improve.

just when I think I have things under control this crap happens...Is it possible the Surrettes are just a pain in the @^#??

[dbcollen]

The closest I could get my surrettes (s530 and s460) were between 1.265 and 1.275, I never got them to be even. I haven't checked sg in a couple years    I may find time to check it in the next few days. I will report the results.

[Halfcrazy]

I do know the Surrettes tend to like Looonnnnnggggggg Absorb times. In an off grid setup I would be tempted to stretch the Absorb way out there. I have no first hand experience but I recall people talking about the Surrette battery wanting like 5-6 hours of Absorb time. You may want to Call the crew over at Surrette and see what they suggest and also see what they consider acceptable variance on SG?

Ryan

[plongson]

If you run the Surrette formula for absorb that is on the Rolls site, the AB time almost is more than available sunlight. I think I'm gonna take your suggestion and really bump up the time on AB. I'll keep and eye on it and see what happens.

BTW...just for my information, how will running up the AB effect the bulk time? I've read reply's here to Vic but I'm still not clear how the two interact.

I have a thought in my head but I'm not going to muddy the waters here if you can give me the Cliff Notes version.

Right now, I'm using about 1 gallon of water/month on 16 (ea) L-16's just for reference.

Paul

[Vic]

Hi Paul,

Well,  my opinions;   In the late Fall  and Winter months,  it is OK to increase the Absorb voltage,  somewhat.   It will result in more water useage,  but will pack more charge into the batteries in the limited time that most of us have.  You might try 59.5  or even a bit more.  Setting up the time as well will help,  as you have nothing to lose.

Know that you are using the RTSes on each charge source,  as you should.   We use 5 mv/cell,  which is probably just a bit too high,  but this will just increase the cold charge V a bit over the ideal,  which should be OK in your situation - opinion.

Would bet that if the batteries are not getting  enough absorption time/V to quite finish the charge on one day,  that the Bulk on the following day would be a bit longer.

It is not really necessary to do a complete recharge on each day,  but many say that doing so several times per week should be fine.  This would require some manual intervention to try to get that extra charge,  using most of the  available CCs.

Recall that Surrette has increased their spec for SG variation within a bank to something like 20 points.  The "rule" on EQ is usually;  EQ until the SG of the lowest cell's  SG stops rising,  but continue about 60 or so minutes after that.  As you know Paul,  the SGs are a bit sensitive to temperature,  and cell temps rise during EQ - especially at 64 V (temp comped) so you may need to T comp the SG values during/just after an EQ.  AND,  I would temp comp the EQ voltage,  given your climate,  although your garage may well be heated a bit.   You may need a bit more EQ time,  from the looks of things.  Just my opinions.  Keep Warm,  Vic

[plongson]

Thanks Vic, I have the RTC for the Classic on the side/center of a battery in the middle of the bank but have never adjusted that setting other than what is default in the Classic setup. Is that correct or should it be adjusted? Not too sure on this one...

As far as a 20 pt spread, I'm within that range, not by much but within. Like you guys mentioned, I'm going to bump the time and voltage and watch it. I'm on a job this week and won't be back to make changes until the first of next week.

I have "problem cells" and know before I even draw a SG sample who is going to be low. One battery acts great overall, and another just wants to be a punk. With so many right on the mark, I think it's more a Surrette issue than an maintenance issue.

I have few things I would sure "Do Over" now I know more about what I'm doing here, and one of them would probably use a different brand of battery...

[SolarMusher]

Allo Paul,
I had had a problem with brand new S-530 and had to deal with Surette.
Surrette told me to EQ 64V for 48hrs at low charge (5Ah per 100AH capacity). Put your batteries with low SG in the same serie and EQ 64V only this serie. Set the Magnum charger to 40% (24A) only and managed temp.
After 48hrs, some cells were still 1.240/ 1.250, Surrette had prefered to change all this string x8.
They told me that after charging these S-530 for 15hrs more they were all fine with 1.275 SG.
I didn't see it 
My advice: do not hesitate to charge, charge and charge (slow, slow) Rolls batteries as long as possible!
You can find varimax in CHARGE----CHARGE TIME------VARIMAX (above your left button) 
Erik