[Dr.Bepis]

Hello all,

I am trying to determine what the voltage output is at the battery jump posts for a healthy alternator. Seems like this information isn't widely available yet for the F48 X1s and my preliminary searches have not been fruitful.

When measured with my multimeter, I was getting 14.05 V at the posts used for jumper cables or trickle chargers. Can anybody confirm if this is low? My E46 typically sees upward of 14.3 and the battery is much further from those posts in the engine bay.

I ask because I have had some intermittent issues over the years that I would typically chalk up to being an alternator issue, but a new alternator isn't a cheap fix unless I'm 100% sure that is the cause.

Currently in the process of getting ISTA+ set up to do some deeper diagnostics, but again, just sort of looking for some anecdotal experience. The biggest problem I've had is the light behind the hazard button will get bright, then dim, then bright again. Each time that light cycles between dim/bright, the headlights will level again, same as they do when the car is first started. Upon cold starts, the heat intermittently does not work. Blowers work great, just seems like the heater control valve may not be opening when called to.

Problems have been happening for some time now. Car has been to the dealer several times for other items and had in-depth inspections, but they have not nailed a culprit yet for this. There have been no breakdowns or anything of the like, but I want to stay ahead of that as this is our more reliable vehicle.

Thanks in advance!

[jrveron]

Could it be a problem with the battery instead of the alternator? Weird things happen when the battery is about to die. How old is yours?

[Dr.Bepis]

Originally Posted by jrveron

Could it be a problem with the battery instead of the alternator? Weird things happen when the battery is about to die. How old is yours?

I suppose it could be the battery. We have owned the car for about 2.5 years and purchased it with ~56,000 miles on it. Previous owner did not have the vehicle serviced at the dealership, but from the maintenance records we do have, I don't see that it has been replaced before.

Once I get ISTA+ running, I can check battery history and the SoC. Thanks for the suggestion!

[MikeG12]

Just checked my 2017 X1 yesterday and got 15.0 volts when running. Not running , I'm getting 12.0-12.2V and "battery Discharged" warnings so I think my battery needs replacement. These batteries don't seem to last long, this is the second battery already.

[Tally100]

Just changed mine on a 2018 56K petrol. was struggling sometimes, I took battery specialist who said might last 1-6 months as it was 450 amps when should be 700 amp. BMW wanted £400 to supply fit and program but local battery specialist provided a verta all fitted and programmed for £160

[mrpingu]

Originally Posted by MikeG12

Just checked my 2017 X1 yesterday and got 15.0 volts when running. Not running , I'm getting 12.0-12.2V and "battery Discharged" warnings so I think my battery needs replacement. These batteries don't seem to last long, this is the second battery already.

Did you code in / register when placing a new battery. I you don't register a new battery this reduces the life of the battery because the Intelligent Battery System tells to charge with higher voltage when the battery ages over time. This is to compensate the aging of batteries but for new batteries this is not needed and overcharging your new battery. You will generally see a much shorter lifespan of batteries if you don't code them in.

[Tally100]

Originally Posted by mrpingu

Did you code in / register when placing a new battery. I you don't register a new battery this reduces the life of the battery because the Intelligent Battery System tells to charge with higher voltage when the battery ages over time. This is to compensate the aging of batteries but for new batteries this is not needed and overcharging your new battery. You will generally see a much shorter lifespan of batteries if you don't code them in.

Supplier fitted and coded the battery for £20