I have a 2003 XC70 with a new battery installed last November. Beginning in January there have been several occasions when car would not start. Local mechanic says that there is a leak in my electrical system that he cannot find. So I am stuck with a car where I never know when the battery is going to be drained to the point where it will not turnover when ignition key is turned. Has anyone run into this problem and solved it.

 

Have you tested the battery to see if it has a bad cell?

 

did the tech measure current draw at the fuse box? Sometimes these can be as simple as the glove box or vanity mirror lights are not going off or a power antenna etc. Start with good VOM (volt-ohm meter) and measure key off current draw for the various accessory fuses (interior lights etc). Keep in mind Volvo hides fuses in like 3 places (hood, under the dash, rear compartment) so the tech may not have measured all circuits. Also measure the voltage on the battery - it should be along the lines of 12.6V with all stuff off. When you start the car, it should go up to 14V or so. Now turn all ALL the accessories - blower, window defroster, AC, radio to put as much load on the alternator as possible. Is the voltage still in the 13V range? (if it drops below 12 then you may have an alternator or voltage regulator issue).