Test Results-Used T-1275s
(Test Results in a later post in thread page 2) What does the peanut gallery think is the proper SG on a well-used battery? I can never figure out if it is 1.275 but on a reduced capacity, or if ...
Forum Discussion
Thanks, Mex. OK I finished the load test (not lab standards!) and decided to quit when voltage just turned to 11.7 from 11.8 under a 19a load at the time.
(Usually, I find that you can go to 11.6 with the 20 hr rate and it will bounce back within the hour to a steady voltage you can use for a rough SOC. The 20hr rate on the 300AH (as new) bank is 15a. So I was maybe quitting too soon. Batteries were disconnected from all loads and were back to 12.09 in half an hour. Again maybe quit too soon. (Trojan says 12.1v is their 50%)
Trojan says 50% is also 1.172 and I was at 1.175 with ambient 70F. However that article said you can't use SG for SOC on an old battery, but you can use the voltage for SOC of whatever remaining capacity it has.
Whatever, Trimetric accumulated AH was 127AH from when started. So capacity is at least 254/300 = 85%. I think it must be higher from quitting too soon and also maybe from not being quite full at the start either. I will pretend they are at 262 or 87%. (The golf car dealer thought they were about 86% using their running time test)
Anyway, it seems these are a safe to use pair of batteries with more capacity than a pair of 6s (262 vs 230 say) They have been running the rig for a few days now as the only batteries and they also hold up well under occasional 100a loads running the kettle, toaster, MW. Obviously they won't last another ten years, but should do a year or two just RVing instead of being in a golf car.
If I wire them up with my four 6s as a bank I will have 262 + 232 + 226 = 720 AH. Ridiculous! :) That's almost as many as Mena has. I'll have to get a bigger microwave.
(Usually, I find that you can go to 11.6 with the 20 hr rate and it will bounce back within the hour to a steady voltage you can use for a rough SOC. The 20hr rate on the 300AH (as new) bank is 15a. So I was maybe quitting too soon. Batteries were disconnected from all loads and were back to 12.09 in half an hour. Again maybe quit too soon. (Trojan says 12.1v is their 50%)
Trojan says 50% is also 1.172 and I was at 1.175 with ambient 70F. However that article said you can't use SG for SOC on an old battery, but you can use the voltage for SOC of whatever remaining capacity it has.
Whatever, Trimetric accumulated AH was 127AH from when started. So capacity is at least 254/300 = 85%. I think it must be higher from quitting too soon and also maybe from not being quite full at the start either. I will pretend they are at 262 or 87%. (The golf car dealer thought they were about 86% using their running time test)
Anyway, it seems these are a safe to use pair of batteries with more capacity than a pair of 6s (262 vs 230 say) They have been running the rig for a few days now as the only batteries and they also hold up well under occasional 100a loads running the kettle, toaster, MW. Obviously they won't last another ten years, but should do a year or two just RVing instead of being in a golf car.
If I wire them up with my four 6s as a bank I will have 262 + 232 + 226 = 720 AH. Ridiculous! :) That's almost as many as Mena has. I'll have to get a bigger microwave.
