Volvo 850 (after being rear-ended) drains battery and shows bad battery (after charging on battery maintainer)

aarem
Mon, 14 Sep 2020 22:05:02 +0000
Maintenance/Repairs

Hi, I am not very well-versed with cars, but I have a 10-month old Interstate battery for my Volvo 850. About a couple of months ago, I got rear-ended while stopping at a red light to turn right. There was not much noticeable damage. However, the battery drains. So, I thought that maybe the alternator is bad and got a battery maintainer. This charges the battery up for a while but then it shows red (bad battery). This has now happened a few times. So, I was going to take it to the battery place to see if the battery was bad, but then the car would not start at all (multimeter reads 8.5V). I put it on the battery maintainer and checked about 3 hours later (the maintainer was yellow, which means still charging), however the multimeter read around 12V. The battery was charged and the car started. So, I decided not to take it to the battery shop because they would probably find nothing wrong with it. An hour later, the multimeter reads 9.5V. What could be wrong? I have no external after-market part on the car, the lights are not left on, etc. What I don’t also get is how the maintainer can charge and then read red: at this time the battery reads around 8V or so. Thanks for any suggestions/help.

48 posts - 11 participants