I have an ammeter, but trying to use it when the machine is under load would be pretty darn difficult.
I've had this particular pair of gel batteries for a dozen years or so, and I got them used. I've never seen a resting voltage above about 13.10 before.
They were 12.77 volts this morning, so I charged them gingerly for about half an hour, then used it a little bit, and charged again for about 10 minutes. Will see what the voltage is in the morning.
landyacht, do you think I should try to add water to these batteries?
One of the pair tends to have some electrolyte leaking around one of the terminals. It's done that for the whole 12 years I've had it. I clean it off once in a while. The other one does not normally do that, but it does have a tiny bit of leakage now since the giant overcharge.
I think you said you have to drill a hole to add water? I'm pretty hesitant to mess with them.