Charlie1979
Junior Member
I'm seeing some strange behaviour with the battery on my 2015 2500. The battery is only 18 months old.
Over the summer, we had occasional issues where the truck struggled to start if it hadn't been used for a couple of days. As the truck was being used fairly often, it didn't crop up too often. We then went on holiday and left the truck for 2 weeks, fully expecting it to not start on our return, but it started no problem.
Over the last month, we've started seeing the problem again. I started monitoring the voltage on the battery, and would see a steady drop from around 12.5v after a drive. As expected, if it got down to below 12, I'd have problems with it starting (although it's never not started, I did have one occasion where it went into some sort of low voltage safety mode, and it wouldn't rev past 2000 - leaving it running for a bit, then restarting fixed that!)
I connected the multimeter up to measure draw, and was seeing a steady draw of around 1.5A. I started pulling fuses but at some point, I managed to blow the 10A multi-meter, so had to give up till I can get a new one (going into town this afternoon).
However, I continued monitoring voltage, and the drop rate seems to have have dramatically reduced - in 3 days it only dropped from around 12.5v to 12.3v, whereas before I'd see it drop to around 12 in a little over a day. Not sure why this would have occurred, as all I'd done is pull and replace fuses (and I didn't blow any in the process!)
The last 2 mornings, I've stuck the volt meter across the battery and it was showing 10v! However, the truck then started without much of an issue. After idling for only 15mins or so, shutting off and letting everything settle, the battery is reading 12.5v.
Anyone have any idea what's going on - there's no way a battery at 10v should start the truck, or that 15 mins of idling would charge a battery from 10v to 12.5v.
The voltage function is still working on the blown multimeter, and I have a separate volt meter, and they both consistently agree, so I don't think it's that.
Over the summer, we had occasional issues where the truck struggled to start if it hadn't been used for a couple of days. As the truck was being used fairly often, it didn't crop up too often. We then went on holiday and left the truck for 2 weeks, fully expecting it to not start on our return, but it started no problem.
Over the last month, we've started seeing the problem again. I started monitoring the voltage on the battery, and would see a steady drop from around 12.5v after a drive. As expected, if it got down to below 12, I'd have problems with it starting (although it's never not started, I did have one occasion where it went into some sort of low voltage safety mode, and it wouldn't rev past 2000 - leaving it running for a bit, then restarting fixed that!)
I connected the multimeter up to measure draw, and was seeing a steady draw of around 1.5A. I started pulling fuses but at some point, I managed to blow the 10A multi-meter, so had to give up till I can get a new one (going into town this afternoon).
However, I continued monitoring voltage, and the drop rate seems to have have dramatically reduced - in 3 days it only dropped from around 12.5v to 12.3v, whereas before I'd see it drop to around 12 in a little over a day. Not sure why this would have occurred, as all I'd done is pull and replace fuses (and I didn't blow any in the process!)
The last 2 mornings, I've stuck the volt meter across the battery and it was showing 10v! However, the truck then started without much of an issue. After idling for only 15mins or so, shutting off and letting everything settle, the battery is reading 12.5v.
Anyone have any idea what's going on - there's no way a battery at 10v should start the truck, or that 15 mins of idling would charge a battery from 10v to 12.5v.
The voltage function is still working on the blown multimeter, and I have a separate volt meter, and they both consistently agree, so I don't think it's that.
