Battery AHr Rating: How to Convert 1 AHr rating to 20 AHr rating
I have access to a used utility (C&D 4LCY7 SAN) battery bank that is currently being replaced after 8 years of service powering switchgear protective relays just because they are 8 years old. The SpGr looks pretty good, the individual cell voltages look good. The configuration consisted of 15 each 8VDC 212 AHr @1Hr rating, weight=310 lbs each. The batteries were originally wired in series for 120vdc. I intend to pick and choose the 12 best batteries from the group of 15 each and make 2 banks of 48V for my solar system. I currently use 3 banks of 8 each 3 year old Trojan T-105 6VDC batteries for 48V which will be replaced by the used battery banks. How would the 212 AHr rating @ 1 Hr compare to the Trojan 225 AHr @ 20 Hr rating? Just looking at the 310 lbs for the C&D batteries vs 62 lbs for the T-105 Trojan tells me they should have more capacity. What is the calculation to convert 1 Ahr rating to 20Ahr rating. The C&D batteries are lead acid type. The used C&D batteries have probably only been cycled to low 12 times in the 8 years during a power outage and have also not been in a controlled environment. Another question is how many years should T-105's last not in a controlled environment in South Texas?
(5.1kw Solar/SMA SunnyBoy 5000 GT String Inverter),( 5.4kw Solar/GT Aurora 300 MicroInverters), (3kw Solar/Xantrex XW6048 Hybrid Inverter with Xantrex XW60-150 MPPT Charge Controller with 3 strings T-105 Batteries (48VDC)), (32 SqFt Solar Drain Back Water Heater), (10kw Bergey Wind Turbine/12kw GT PowerSync Inverter).