Think my 12vdc battery is about to croak......

PaperSniper

Member
West Tennessee, USA
I saw a brief message today which said something like "Weak battery.....". My car and battery is from sometime in 2020. I bought the car in July that year. I figured the battery might be going out sometime soon. My car has only about 19k miles on it, although I do drive it every 10 days or so at least 20 minutes to keep the battery up and the fluids and other equipment "exercised".

I know the dealer would be happy to replace the battery for me, but I suspect he will charge a lot. Where else have folks had batteries replaced? I'm in the USA. There are several Auto Parts stores that probably have a replacement battery, plus of course Costco, Walmart, etc.

Any suggestions on where to get my battery? If you had one replaced other than at the dealer, what about all the electronic stuff that could be set to default, etc, by doing that?

Doug
 
I had mine replaced last year at a BMW Service Centre here in the UK. Apparently the car is hooked up to an external power source so nothing gets reset to default. That was certainly my experience. The total price was £340 (approx US$420).
 
Be aware that a message similar to yours appears in the central display (within the steering wheel) when the battery in your key fob is low,

I had that on my first G29, it’s simple to do, and the CR2032 battery costs a pound or two.
 
dr_john said:
Be aware that a message similar to yours appears in the central display (within the steering wheel) when the battery in your key fob is low,
I had that on my first G29, it’s simple to do, and the CR2032 battery costs a pound or two.

Thanks to you both. I have had to replace the fob's battery once about 2 years ago. I hope it's just the fob battery, but I think the dash said something about "...drive....". My Z4 is 4.5 years old and gets very little use as I posted initially, so I'd not be surprised if I need the fob or the car battery. I wish I'd paid more attention, but I was in a hurry. I'm going to start the car again this weekend, and if I get the same thing but it's the fob, I'll be happy. Otherwise, it's a trip to the dealer.....sure don't need a $420 battery! But then I don't want to get stuck somewhere without power either.

Doug
 
If you don't do it already. Pop your battery on Charge, when the car is not being driven. I've had batteries last 10+ years in weekend cars. Just need to take car of them, if you are able to. :wink:
 
buzyg said:
If you don't do it already. Pop your battery on Charge, when the car is not being driven. I've had batteries last 10+ years in weekend cars. Just need to take car of them, if you are able to. :wink:
I have thought of that. I used to put a charger on my motorcycles and lawn tractor when not in use. They probably helped, but wow - 10 years? In my experience I think I gained maybe another year, so around 5-6 years was the longest I saw on my motorcycle batteries.

OTOH, I have a charger doing nothing in my garage now since I no longer own motorcycles nor a lawn tractor......

Doug
 
Batteries often only last 3-4 yrs although I’ve had them last 10yrs but not often. The first sign of failure is often the Stop/Start not working or windows loosing their positions, or multiple unrelated faults.

You can DIY change a battery but it does need to be coded to the car to charge properly, most garages will be able to do that, not just a dealer.
 
deltasierra said:
Batteries often only last 3-4 yrs although I’ve had them last 10yrs but not often. The first sign of failure is often the Stop/Start not working or windows loosing their positions, or multiple unrelated faults.

You can DIY change a battery but it does need to be coded to the car to charge properly, most garages will be able to do that, not just a dealer.
Thanks. This week I hope to start the Z and see what happens. I'm hoping it might just be a warning the battery in the fob is going, but I kind of doubt it. That battery in there is only 2 yrs old I recall. If it turns out I need a car battery, I'll be researching the places around here, including the BMW dealer, to check their prices and determine their ability to do the job correctly.
Doug
 
I have a similar aged G29 and same mileage. I also have experienced the message and usually when the car hasn't been driven for a while especially in winter months, or just for short journeys. Stick it on trickle charge for a while and it should be fine.

Mine will be left in the garage for a couple of weeks from Friday due to holidays, so it will also have a charge before then.
 
Nanu said:
I have a similar aged G29 and same mileage. I also have experienced the message and usually when the car hasn't been driven for a while especially in winter months, or just for short journeys. Stick it on trickle charge for a while and it should be fine.

Mine will be left in the garage for a couple of weeks from Friday due to holidays, so it will also have a charge before then.
Any suggestions on how to hook up the charger? I'm a 78 year old guy but reasonably adept at such things. I used trickle chargers on motorcycles and lawn tractors before, but those had battery terminals to which it was easier to connect. I have not taken the floor off the boot/trunk before, but I believe the battery sits back there as opposed to residing in the engine compartment.

Doug
 
Correct the battery is in the trunk (boot). However the correct terminals to use to charge it are in the engine compartment.
LHS (as you look from the front) you will see the positive terminal covered by a red cap.
There are a couple of bolts close by to use for the negative lead.

The battery will be an AGM one, so you should use a charger with this option. i.e a Smart charger
My understanding is that using a standard trickle charger can damage an AGM battery
 
obewan said:

Thanks, obewan. Glad you told me where the terminals are to charge. Naturally, however, they are in the most difficult to access area in my garage! That's okay, I will figure a way......maybe use my skinny wife's arms to reach in there. :oops:

Doug
 
Try one of these "CTEK MXS 5.0 Battery Charger" it may improve your current battery, if not, atleast you will have a decent battery charger/conditioner for you new battery.
 
battery.jpgI have mine hooked up to a Ctek when it's sitting in the garage. Reading the brochure these are the two connection points under the bonnet for connecting the trickle charger.
 
My car seems to have a 92 ah original bmw battery that seems to have passed its best time.
Will try to revive but maybe new one is needed.
Anyone have installed the 105 ah (for compatibility check)?
 
Back
Top Bottom