using the taous charger that comes with the GM kit my 36v 13ah sla battery used to take 6-8hrs. I'm guessing 9-12 hrs depending on temp and how many internal shorts you have. In the end my charger couldn't detect the peak to shut down because it was shorted so bad internally. A 120v charger rated at 60Watts draws 2amps so my nominal charge for 13 amp hours is divided by two. Give or take, at sea level, at room temperarure, on a bump, on a log, in a hole, on the bottom of the sea. Or when the green light turns red.
