Recommendation for New Batteries?

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Re: Recommendation for New Batteries?

Postby troll334 on Wed Jul 01, 2015 10:19 am

New Bank - Sanity Check
Hey Folks, it's been a while. My apologies for not contributing; I felt inadequate; but now...I've got some real-world experience under the belt. Perhaps I can now help some folks!
I'm on a new bank after almost 5 years! Duracell (East Penn Deka 6V 230Ah) in case anyone's interested. I thought I'd throw this out there for a sanity check:
First, the recently decommissioned bank (24V) started dropping, almost immediately, to 24.8V under load (just after Mr. Sun went down). Although the no-load surface V was 25.8 I just knew I had hopelessly sulfated the heck out of 'em. This behavior had been happening for the last year. As well, during the years of SG testing, I'm certain I laid the tip against some vaseline and hence polluted the cells (light film noticable on surface). Oh, the single load is a standard fridge (1A run on AC side, about 6A on DC side). The bank was (and is) sourcing about 660Ah (690Ah new bank; so they say). I also noticed a .3A flow differential between strings on charge and discharge. Still have it with the new bank so I must have a resistance issue with wiring/connections. The new bank has been in a production mode for two weeks now. All cells reading 1.28 just into float. In fact, the following morning, SG readings are 1.275 (happy dance).
Last, upon receipt and wiring up the new bank, keeping the loads on-grid, I performed a full charge on day 1 then an EQ on day 2 (then topped off the cells). End amps for day 1's absorb was 6A while End amps for day 2's EQ was between 5-6. I am now no longer being lazy, laying the hydrometer on the batts between readings and am also douching with clean distilled after each use.
I've set the MX-60 to absorb for 3 hours and an auto-EQ every 30 days (absorbed for 4 hours until yesterday; don't wanna cook 'em more). As I write this and monitor remotely, I see 28.7 @ 9A (90 minutes into absorb). The Ah taken out overnight is typically around 60Ah. Constant monitoring and recording the characteristics, as I continue to do, may lead me to EQ at different intervals but for now, I know I need to EQ more than just a few times / year like I did with the deceased bank. To help diagnose the flow differential between strings, I'm going to move the interconnects (three at a time) between strings to see if the problem follows. I've already ohm'd out each interconnect but the res on my multimeter doesn't go beyond 10th's; I see no difference with that.
My bulk rate (max recorded) seems to be 40A although the PV string and the MX can source 62A; acceptance on the new bank is sweet (yes, I've set the MX to allow more than 60). I know as time goes on the batteries will likely take more than 40A during bulk (aging, etc.); but for now, the demand just doesn't seem to exist (the charge curve is textbook).
Any thoughts or opinions?
Thanks!
mike
troll334
OutBack Whiz
 
Posts: 47
Joined: Mon Jan 23, 2006 3:56 pm
Location: Fort Lauderdale, FL
My RE system: VFX3524, MX60, Mate, Hub4, 1570W STC, TriMetric TM2020, 16.5 KWh Deka GC15 Flooded.
Supporting one standard fridge for now. Bring on the hurricane; I'm ready w/ Outback!

Re: Recommendation for New Batteries?

Postby billjustbill on Sat Feb 27, 2016 2:31 pm

I'd like to hear how things are going or how they went with your (and other posters',too) decisions for batteries since the was started so long ago... :grin:

I'll have a new array up in the next four to six months. It's a ground array for a 4kw system using two GVFX3524.

I'm really considering a forklift beast, 24v battery. Would you share your insight and any experience with this type of battery for solar ?

Thank you,
Bill
Be Not the First on Which the New is Tried,
Nor the Last to Lay the Old Aside
billjustbill
Member
 
Posts: 23
Joined: Sun Dec 19, 2010 10:07 pm
Location: Texas
My RE system: Beginning to assemble parts for a 3.5kw system with 30 Kaneka fixed panels and building a large tracker wit 12 Kyocera 135 panels. The focus is to be as much off the grid as possible with two GVFX3524 from an eight batteries for a 24v U.S. Battery 840ah bank.

Re: Recommendation for New Batteries?

Postby troll334 on Fri Aug 05, 2016 5:51 pm

Hey Bill,
Sorry for the huge delay...
Not that it matters now, but I'm very happy with the performance of my system including the current bank. I've had this (my third) bank of batts for 14 months now. Things are really looking good. I'm still only allowing about 15% DOD (overnight load; single fridge). Most days, I attain a full absorb cycle (min 3 hrs). This appears to be the 'sweet-spot'. I'm performing an EQ charge every 30 days. This keeps S.G. uniform among the 36 cells and yields between 1.27 and 1.3 (depending on S.O.C. of course). I'm having to water every couple-3 months to the tune of about 2 gallons (for the 12 batts); never dropping below 3/8" above the plates. I learned that lesson, the hard way, with the first bank 10 years ago. My only complaint, those d@mn clouds! :lol: Hey, I'm in the Sunshine State; yeah right ](*,) . I have no experience with any batts other than the little 6V wet-cell blocks. Again, sorry for the delay. Back to college (at 53) to keep my job; just in time to retire!
Hope all is well with your config.
Best regards,
mike
troll334
OutBack Whiz
 
Posts: 47
Joined: Mon Jan 23, 2006 3:56 pm
Location: Fort Lauderdale, FL
My RE system: VFX3524, MX60, Mate, Hub4, 1570W STC, TriMetric TM2020, 16.5 KWh Deka GC15 Flooded.
Supporting one standard fridge for now. Bring on the hurricane; I'm ready w/ Outback!

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