Regen discharge problems PL8
I am trying to cycle a pair of 5s5000 25c packs on the PL8. I've done it before with a previous PL8 (that was defective and replaced by FMA), but this one won't do it. I have it connected to a car battery showing 12.3 volts, have the charge rate set at 6.5amps, and the discharge set at 18.5 amps, set at High Power. Whether I choose 2P or N makes no difference. Asking it to do 5 cycles, but it will only charge at 6.5A but the discharge peaks at 5A and just sits there for hours. If I tell it to Regen Discharge Only, same result. It seems to want to initially shoot up in discharge amps, maybe reaching 12 amps but quickly backs down to less than 3Amps then back up to around 5A.
Don't think the battery is at issue, since it is a frequently used deep-discharge Optima.
Help is appreciated.