Hi all i am looking at a 2008 diesel ford focus that has a parasitic battery issue

car has had 2 new batteries of late and an alternator change, owner says when parked and locked battery is drained to not able to start in less 30 mins any ideas?

He has been disconnecting the terminal every time he travels anywhere lol bit of a nightmare that

going to pop over later or tomorrow and take a look

 

thanks in advance 

J

As none of the experts has responded yet I'll help by giving a bump:

A 2008 car won't have a battery monitoring system (according to @JW1982) but the ECU on these models might still monitor the battery voltage and cut out the starter if it falls too low. I'm not sure about that so hopefully one of the pro's will be along soon to give a better insight. Even so, a drain that could bring a new battery down that quickly must be quite large and I'd have thought that anything drawing that sort of current for 30 minutes would be getting pretty hot. Maybe there's a problem with the smart charge system that's not keeping the battery charged. The obvious first check would be a multimeter across the battery with the engine running. The voltage should be in the region of 14.4V. With the engine off It would be interesting to check how quickly the voltage drops off.

It must be a big draw for it to not start 30 mins later. 

I'd still disconnect the negative battery and use your multimeter set to amps to measure the current draw with the car locked etc.

If you're going to do that I'd have a spare fuse handy for your multimeter. They're usually 10Amps max and this current might be higher than that.