Quote Originally Posted by R19 View Post
I remember going over DC voltage last semester in class at school. I went and looked in my text book and 12.67 V at 68 dergees F is considered charged. If the dempature drops to 20 degrees F 12.0 V is considered dead. At 68 degrees F a fully charged battery will normally read 13.6 V + or - .2 which = 13.4-13.8V. Just 1 drop in volts can drastically reduce the performance of a 12v battery.
Ah yet you need to figure in the 10% voltage rule. Voltage fluctuation is figured at the 10% rule for operation being ac or dc. 12 volts is 12 volts. His sounds like an amp problem. You can have 12 or 13 volts all day yet if you don't have the amperage to back it up your dead in the water.