V50 - Something is draining the battery, how to investigate?

[mogle]

We have all had a flat battery? The car is not modified. How can I best find what is draining the battery?

After driving around for one hour, I parked the car at home. 30 minutes later the car would not start? Strange. The battery was flat! Strange, since everything is on auto, the light turns on when the car starts. No light was turned on in the cockpit.

I had the battery replaced at a Volvo garage 5-6 years ago. Sadly no date on the battery. Checked the alternator, it generates 14.2 amp when the car is running. With the key out of the car, I could hear that a small fan or something was running. AC and everything else I could think of was turned off. It was not enough juice to start the car.

Tomorrow I will receive the new battery from Euro parts. Sadly I think that will not be the end of it. If something drains the battery, it is just a question of time before I got a flat battery.

What is the best way to check what is draining the battery?

- Easy option, send the car to my Volvo dealer. (My local mechanic is not doing electric.)
- Look in the manual and take out most of the fuses. Try to identify the fault that way?
- Find a local shop that does electronics?

Any tips?

[BJB]

Could do with using an Ammeter linked between the Battery Positive terminal and the Positive clamp. This will give you an idea as to how much drain it is having first.

[mogle]

Could do with using an Ammeter linked between the Battery Positive terminal and the Positive clamp. This will give you an idea as to how much drain it is having first.

That is a piece of good advice. I would expect that the car alarm will always draw something.

When I have changed the battery I will get the ammeter out.

[bugsb]

apart from testing a common fault can be the alternator.
2nd get one of these mine has paid for itself 100 times over this was the fisrt i came across there are digi ones out now i just know this type is very good at load testing
https://www.ebay.co.uk/itm/Battery-Tester-6V-12-Volt-Load-Drop-And-Charging-System-Checker-Auto-Car/283724176972?_trkparms=ispr%3D1&hash=item420f475e4c:g:21kAAOSwGrBeBeDO&enc=AQAEAAACQBPxNw%2BVj6nta7CKEs3N0qXKRh5ILldQF6uI ciMDbitO3oTmC08rRO%2FKVQR%2FbquRodDrS1lJ5vZKAHD56h OA83RAyOR1oKTO8%2FCqvoy8VE7%2B19v8f6Khhf2pkOcIGTiU NBx%2BiVJR%2F2GDnL0dXcakuOzKYAFMghNKn3BO3Oss%2BIrx jeFqmtpC40thI8GGFRhbP67ZRwd2PQW%2F5QvCua71lcewvluo kYO6y9i7TsY69QYh1JuZJu6RuJ3PJXKiSzQ6FreTfBATjTFWbB g8usztvCkkuY%2FS8wmqlt4%2BxZEmrVDIIcvLPy2%2BiWZwIv mmmt6OiJY7vGqrKasLN5Q7VFcF5Yk4hNr6u2%2FXFkQenWVCZD NDogU5CmC85lSjVGBb38nyK6JWp71SdssRU5%2BD8nmD5qZXR3 aMd5hpB1DMHYWQ3ugHQtp9lXmo6TA%2BtACufQUmFsUIyPBjkL 70uzcw%2B7sCihxZr7n4qTTGC3Dqj1ThqKinEnKEukc8s4hzpk pX2GRTrKTLlwmhIS55i7Y5wst4tEWbMXSPpCtNaxuGOXKSPCeF P07zwAueNcqu19B04bBw2bfoqLiXL8DAARPCIO7DnLXC1ObB47 jyrB3TuhiCUYmgYgyHa7X1icBHMFUdj5TMpE4DDsIFIaIBCfec Pty6VdVnXICMCrDHS%2BtHIP0A1r%2BdbssnaoCYaFzqWa4CMK HHsq3Ys9y6TQXk%2Be8hBGvJ8kFMb72PkK0Q9gW%2BPwtI3agK bSTeIwYve3cKUiZsL2WKRA%3D%3D&checksum=2837241769728e62ce4378ce45d48c2a1af5306f9 94f&enc=AQAEAAACQBPxNw%2BVj6nta7CKEs3N0qXKRh5ILldQF6uI ciMDbitO3oTmC08rRO%2FKVQR%2FbquRodDrS1lJ5vZKAHD56h OA83RAyOR1oKTO8%2FCqvoy8VE7%2B19v8f6Khhf2pkOcIGTiU NBx%2BiVJR%2F2GDnL0dXcakuOzKYAFMghNKn3BO3Oss%2BIrx jeFqmtpC40thI8GGFRhbP67ZRwd2PQW%2F5QvCua71lcewvluo kYO6y9i7TsY69QYh1JuZJu6RuJ3PJXKiSzQ6FreTfBATjTFWbB g8usztvCkkuY%2FS8wmqlt4%2BxZEmrVDIIcvLPy2%2BiWZwIv mmmt6OiJY7vGqrKasLN5Q7VFcF5Yk4hNr6u2%2FXFkQenWVCZD NDogU5CmC85lSjVGBb38nyK6JWp71SdssRU5%2BD8nmD5qZXR3 aMd5hpB1DMHYWQ3ugHQtp9lXmo6TA%2BtACufQUmFsUIyPBjkL 70uzcw%2B7sCihxZr7n4qTTGC3Dqj1ThqKinEnKEukc8s4hzpk pX2GRTrKTLlwmhIS55i7Y5wst4tEWbMXSPpCtNaxuGOXKSPCeF P07zwAueNcqu19B04bBw2bfoqLiXL8DAARPCIO7DnLXC1ObB47 jyrB3TuhiCUYmgYgyHa7X1icBHMFUdj5TMpE4DDsIFIaIBCfec Pty6VdVnXICMCrDHS%2BtHIP0A1r%2BdbssnaoCYaFzqWa4CMK HHsq3Ys9y6TQXk%2Be8hBGvJ8kFMb72PkK0Q9gW%2BPwtI3agK bSTeIwYve3cKUiZsL2WKRA%3D%3D&checksum=2837241769728e62ce4378ce45d48c2a1af5306f9 94f

[Wiseacre]

I was having this a few years ago on my s40. multimeter on battery terminal and pull fuses, starting with the most likely culprits. turned out it was the circuit with the stereo & sat nav on that was drainaing 3 amps when the car wasn't running. removed the fuse and no issues since, apart from I can't listen to music! there's a thread on it somewhere...