[RE-wrenches] Testing AGMs

[Ray]

I agree, I usually steer full time off grid customers away from AGM, but 
for remote sites that might not be attended for months at a time, AGMs 
do have a purpose.  We've had good luck with Full River. Load testing is 
one really long way to test; I usually just have the customer do load 
testing with the system and the Trimetric or other SOC meter.  Run a 
good charge cycle, then turn off the solar for a couple of days, and see 
what kind of capacity is left.  Also always good to check voltages of 
all the batteries, and see if there are weak or dead cells.  Dead cells 
show up pretty easily, they will test 1.5 to 2 volts lower.

My latest toy purchase was a FLIR camera, it has been extremely 
helpful.  You can literally see the dead cells within the packs. They 
show up noticeably warmer than surrounding cells.  If you see anything 
like that, you know the pack is probably toast.  Finally, a really good 
test is how old they are.  If they are rated at 300 cycles to 80% DOD 
battery and they are 5 years old, they're probably gone as well.  Most 
AGMs do not have long cycle lives. Folks don't call to complain about 
batteries unless they're not working right.  I listen to my customers; 
they know better than anyone when the system isn't working the same, and 
after checking for new loads, and proper charge settings, its almost 
always batteries.

Ray

Remote Solar



On 2/24/18 5:20 PM, Dave Angelini Offgrid Solar wrote:
> Load test and compare with another known good battery. I also steer away
> from AGM's.  --Dave
>> Wrenches,
>> We have a client with a string of sealed L16s and he believes he may have
>> a weak or failed cell.
>>
>> What’s the best way to test or check these batteries, since there is no
>> electrolyte to draw out.
>>
>> We don’t install many AGMs, in fact, steer the client away from them,
>> usually.
>>
>>
>>
>>
>> Jeremy Rodriguez
>> Solar Installation And
>> Design Expert
>> All Solar, Inc.
>> 1463 M St
>> Penrose Colorado 81240
>>
>> Sent by Jeremy's iPhone. Sorry for typos and shorthand!
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