Trying to bring an old unit back to life and have encountered a Code 9F. Unit has worked well for us in the past.

It has been out of service for 2 years. We charged the battery with a golf cart charger after checking water levels (our good charger is 100Ft away and haven't figured out a way to move this truck).

Got it to 23.2V. That should be good enough to start, right?

Power on goes into self test and then gives me a Code 9F. Anyone know what this is before I call a service tech? I'm Stuck.

Thanks all!

Scott