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@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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