Trojan T-125's finally gone
Well almost. After 14 years a heavy use, usually 25 to 50 or more discharges to 25 percent SOC each year they are finally ready to get recycled. This year I couldn't get the voltage up past a...
Forum Discussion
ktmrfs wrote:
...
for the 10 years I had them I was prudent but not anal about maintaining them. I have a trimetric monitor and on most outings they would get down to anywhere from 25% to 40% SOC (60-75% DOD). I was running a dorm fridge, cpap and furnace off them in a homebuilt small toyhauler. Then I'd hit them with the generator and a PD45A charger till they got to about 80%SOC, and repeat. Once home I'd let them get to as close to 100% as I could, but the PD will only get to 14.6V less than what trojan wants.
...
Those are deep discharges!
Roughly how many times a year would you go down to 50% or below?
You've prompted me to take another look at some battery's life cycle charts.
I can't find Trojan's cycle life graph for the T-125, but the T-105RE can do over 1000 cycles when pulled down to 20% SOC.
So you could, theoretically, do 20%SOC 100 times a year over ten years (with no other use). Most people don't even use their batts 100 times a year.
Maybe I'm being too anal about my self-imposed 50% limit. But my cheaper batts (US2200 and Duracell GC2s) aren't near as good as the T-105RE. The US2200 has about the same number of cycles (1150) but that's when pulled down to only 50%. There's only 675 cycles at 20% SOC.
Still, maybe I shouldn't freak out if SOC drops below 50% a few times a year.
Thanks for your report!
