I am working to fine tune my charging cycle for my 8 ea. EnergyCell 200RE batteries (two strings @48V) and have a few questions. At present, I only use a generator to charge the batteries - no other charge sources are connected.
1) I have read two different maximum charge current specs for the 200RE - one is 30ADC per string and the other is 50ADC per string. Anybody know which is correct?. I am currently using the 30ADC value to be safe. I do notice that my battery temp does not rise much from ambient when charging at 30ADC.
2) How do I know when the 200REs are fully charged? I do have a FNDC in the system and it is set to terminate the charge when the end amps are < 7. I have set the FNDC up using the "FLEXnet DC Programming & Guidelines" document. One method is to measure the open circuit terminal voltage at rest, but this is not very convenient when needing to wait for 24 hours of battery rest time before the measurements are valid.
3) Is it bad to re-bulk the AGM battery bank frequently? To insure a full charge, I have repeated the bulk charging cycle on a couple of occasions - start a bulk cycle in the morning, wait the charging cycle to fully complete (I have no float time programmed since I am on a generator) and then restart the bulk charging cycle and wait for it to complete. During these charging cycles, I see no significant rise in battery temperature (maybe a couple of degrees). Any thoughts?
4) What is the expected terminal voltage for the EnergyCell 200RE at 100% SOC and at 50% SOC? I have read many articles, but most seem to focus on flooded lead acid battery technology.