1998 Grand Cherokee Ovis my Battery goes flat overnight not always some days ok then another day flat ,I have fitted a New battery but just the same.It has LPG fitted and I thought it was if I did not turn it off this would cause it but no. I went on a 100 mile trip yesterday so battery was fully charged ,this morning agian flat, only diferrence today I did not lock the vehicle just removed the keys , Could this play apart with this issue ? any ideas please.

 

You need to check for a Parasitic Drain
http://www.wikihow.com/Find-a-Parasitic-Battery-Drain

Worth a try!

 

Thanks for that Morat ,
But I made sure I locked it via key fob , and OK today, just maybe it has to be locked when not in use and it will be OK cheap fix if it is the case, should keep locked really but we do tend to leave everything unlocked and open with out any trouble here.

 

Still cant find it, so have fitted quick release battery termanals ,every night just unclip one job done, just have to reset the radio which is no worries, cheap bodge

 

That'll do it, but your ECU will lose its adaptation settings so you might have some rough running for the first few minutes until it relearns the fuel trims.

I'm probably going to have to go through this routine myself soon, I've replaced the alternator on mine and the battery is still dying over 3-4 days without use. I'm hoping that with a new alt, a new battery will be OK - but if it isn't I'll definitely be pulling fuses!