Parasitic draw

[Guest]

Batteries go flat in 2hrs

[carriedi]

wow, is that s fully charged good battery? Are you saying that the battery voltage goes to zero after two hours? Or are you saying that it won't turn the engine over after tow hours of being charged all the way up?

How cold is the temperature where you are at? Very low temperatures can cause a battery to not star the engine.

If the battery goes so low that the lights won't even work I would suspect a bad battery. Lights don't take hardly any amps to run.

Do you have any aftermarket draws on your battery? (like a big amp that isn't switched off when the key is off?)

Using an amp meter could tell you if there is a big current draw on your battery. Don't use an in-lime ammeter because your draw may damage the meter if the battery draws draw in just a couple of hours. Use an inductive meter around the battery cable to start finding the draw..

what is the year make modle and engine of the vehicle you are having the problem with?