> To charge the internal SLA battery in the k2 you need 13.8 > to 14.5 volts at the battery. 14.5 volts is good for the initial part of the charge but if you leave the battery with 14.5 volts attached, you will overcharge it and shorten the service life. The K2 battery is designed to be left on a float charge at 13.8 volts.