[RE-wrenches] How Best to Load Test 2 V Cells

Wed Jul 14 16:15:58 EDT 2021

Hi Jeff

If it’s the energy cell xlc from Outback then it shows an eq requirement. 

If not that battery, most industrial quality VRLA  I’ve seen have a eq requirement, conditioning charge or something similar. 
And the lowering of capacity is common from experience. 

Question
What equipment/brand  is charging it?

Jay

Peltz power

> On Jul 14, 2021, at 1:49 PM, Jeff Clearwater <jeffc at villagepowerdesign.com> wrote:
> 
>  Thanks Dave - yes I've done whole pack load testing.  The deal with this pack though is that it is so remote and the expense of "just replace the pack" in terms of shipping and labor is extreme - (tiny Bahaman island with only regular small boat access}
> 
> And if it was toward the end of the pack's life anyway I'd not mess around - but with only 600 well documented cylces on a $25K pack - and with probably half that again in shipping and labor to replace - I'm needing to carefully document the lagging cells for either a warranty claim or at least to make good decisions going forward.
> 
> It's easy to access the cells as this is an EnergyCell AGM stack with easily accessible terminals and removable terminal bars.
> 
> If we replace we'd go LFP - on the order of 100 KWHrs.  So no small decision for the customer - so worth the testing.
> 
> Thanks!
> 
> Jeff Clearwater
> Village Power Design
> www.villagepowerdesign.com
> 
> 
> 
>> Dave Angelini Offgrid Solar July 14, 2021 at 10:32 AM
>> I can ask my battery guy! He is the best with AGM and a dealer for full river and concord. He does this alot! Saves a bunch. He always says that most of the warranty is just a full/corrective charge and 80% are good. Undercharging is the problem. Very very few are overcharged. His words! I just replace the bank, no time to play with this stuff.
>> 
>> However, I just do the same thing I do with any bank of individual batteries. I put a large load on the bank with the inverter and look at each cells voltage. You may have done this... 
>> 
>> The hard part is, depending on the make, is pulling the cell and doing a full charge and EQ if it is the make that allows it.
>> 
>> The other hard part is just getting batteries these days. I just heard Trojan is 8+ months out. You know what Steve from RollsSurrette has said. 8 weeks I think.
>> 
>> The easy part, what make is your cell?  
>> 
>>  
>> Dave Angelini Offgrid Solar
>> "we go where powerlines don't"
>> http://members.sti.net/offgridsolar/
>> e-mail offgridsolar at sti.net
>> text 209 813 0060
>> On Wed, 14 Jul 2021 10:16:31 -0700, Jeff Clearwater <jeffc at villagepowerdesign.com> wrote:
>> 
>> Jeff Clearwater July 14, 2021 at 10:16 AM
>> Hey Good Folks,
>> 
>> I've got a 2300 AH AGM pack of 2 Volt cells that is showing signs of premature aging (only 600 cycles) and I need to test the AH capacity of each cell to help the customer make decisions going forward of whether to replace individual lagging cells or the whole pack.
>> 
>> What equipment have folks used to do AHour tests on 2 Volt 2300 AH cells?  I've done plenty of load testing on 6, 12, 24 and 48 volt packs as a whole but am not sure what's my best approach is for 2 volt individual tests.
>> 
>> I know I could put a  resistance load and then use an AHour integrator unit - but does anyone know of what unit and what resistive load I'd use at 2 volts?  That would be a large device at that voltage to get any appreciative wattage! - I'd like to do a 10 hour test at most.
>> 
>> I see 2 V test units on the web but they only appear to be hooked up for a small amount of time - so they can't be testing full to empty discharge AHours.  
>> 
>> Thanks!
>> 
>> Jeff Clearwater
>> Village Power Design
>> www.villagepowerdesign.com
>> 
>> 
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