[RE-wrenches] Test procedure for Concorde batteries

[Ray Walters]

Hi Gary;

I think it would be a waste of time to load test a sealed battery that 
is 9 years old.  Even at only 20% discharge, that battery only has 2800 
cycles.  At 80% discharge, its 550 cycles.  The daily system cycle is 
probably roughly a 10% cycle, coupled with the frequent deep cycles.  We 
have been seeing 5 to 7 years in GTB systems with regular sealed 
batteries.  Even in float mode, they don't last forever.
Also the customer has already done a basic load test, and the battery is 
failing.  Its only a matter of time before you start seeing cell 
failures, and then the system won't even work when the grid is up.
I'd just replace the set on your next trip.

R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760

On 9/1/2016 2:00 PM, jerrysgarage01 wrote:
> Wrenches
> You can do a carbon pile test but the best way is testing under 
> several conditions. Here is an option real easy and maybe faster, put 
> a volt meter on each battery under constant charge conditions, higher 
> volts on one battery meens high resistance in battery, low volts meens 
> low resistance, either extreme can be an issue.  Then let sit for at 
> least an hour with no load and check the volts, next put a fixed load 
> on the system, again a volt meter check each battery,  here you may 
> find a lower reading then the rest, there is the problem, now replace 
> the entire bank not just the single battery. This is an easy test and 
> the customer can see it easily too.
> Jerry
>
>
> Sent via the Samsung Galaxy S™ III, an AT&T 4G LTE smartphone
>
>
> -------- Original message --------
> From: Gary Bassett
> Date:09/01/2016 2:51 AM (GMT-10:00)
> To: "RE-wrenches (re-wrenches at lists.re-wrenches.org)"
> Subject: [RE-wrenches] Test procedure for Concorde batteries
>
> We have a grid tied battery backup system that uses 8 Sun Xtender 
> PVX-2120L batteries, about 9 years old. The grid has been going out 
> frequently – about 4 times in the past 3 weeks. When the grid goes 
> out, the battery voltage gets too low and shuts the system down pretty 
> quickly. One of the times, this happened within 4 hours. We want to 
> test the capacity of the batteries and we have a testing procedure 
> from Concorde that seems like it would take a lot of time. Is there a 
> quick way to test the battery capacity?
>
> Gary
>
>
>
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