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Mazda CX-30 - Battery problems - davecooper

I have been having battery problems for some time now. When the car was only 6 months old, it was in an accident and spent seven weeks being repaired. The damage was rear end only. When I got it back, I started getting starting problems where one day it was fine and the next day it was pretty much dead and I had to get recovery out to start it. (I subsequently bought a booster/charger).

My initial thoughts were that it had probably spent its time at the repairers being started and stopped as they moved it around the shop without any long running to charge it. It was also delivered back to me on a trailer so still no long run. I have given it plenty of long runs since then but the problem occasionally rears its head when it suddenly won't start one day. Now that I am retired, I don't do the mileage I used to but still do enough to keep the battery charged I would have thought. However, the battery voltage always seems low, even shortly after a long run. Last Sunday I came back from 600 miles of mostly motorway driving over the previous week. I checked the battery voltage this morning and it was 11.6V. Surely it shouldn't have dropped this much in four days!

Anyway, I contacted my dealer to ask if I they could do a battery check and they said they could but it would be £132! I asked if this would be covered under warranty as the car is only two and a half years old and they said they didn't know and it would have to be taken up with the warranty company.

Ultimately I an not sure what to do. I could get a free battery check at a number of places but they would expect me to buy a new battery from them if it was goosed. I am concerned about getting it checked at the dealer as they may say it is not covered under warranty and it would cost me less than £132 to get a new battery in the first place.

Edited by davecooper on 18/05/2023 at 13:47

Mazda CX-30 - Battery problems - _

Google." Auto electrician" also check reviews of said people.

Check battery connections and alternator output.

I'm sure elekie and ac doctor will be along shortly to inform you more.

Mazda CX-30 - Battery problems - elekie&a/c doctor
Battery reading 11.6 volts tends to suggest it’s toast . Buy a new one and forget the warranty.
Mazda CX-30 - Battery problems - davecooper

That's probably what I will do. Is it at all possible that there is an excessive drain on the battery while the car is parked and locked?

Edited by davecooper on 18/05/2023 at 16:25

Mazda CX-30 - Battery problems - elekie&a/c doctor
Unlikely. If the battery is only showing 11.6 volts after your long journey, I would think the battery is goosed. No driving activity for 6 weeks has probably finished it off .
Mazda CX-30 - Battery problems - sammy1

Mazda not very helpful are they. Surely you could ask them if the battery is covered by warranty. The time being repaired is a no consequence to them. Many 3 year old cars are left standing for long periods and start OK. Whatever the likes of Halfords will test your battery and a battery from them will be a lot cheaper than the Mazda dealer. You could buy a battery and it could be the cars charging system which would be a warranty job

The repair company may have disconnected the battery while working on the car so check the terminals. Where is the battery located?

Who are the warranty company if not Mazda??

Edited by sammy1 on 18/05/2023 at 18:22

Mazda CX-30 - Battery problems - davecooper

The dealer I bought the car from have now stopped selling Mazda cars to concentrate on Volvo and Dacia. Another dealer in the area has now taken on the Mazda franchise in place of Peageot! The problem is, the new company say they are still in the process of managing the changeover so perhaps not the ideal time to deal with them.

However, I am going to contact another Mazda dealership who I have dealt with quite a lot in the past and see if they are any more helpful. If I do replace the battery out of my own pocket, I certainly won't be going to a main dealer to get it done.

Mazda CX-30 - Battery problems - edlithgow
There may be some ‘new car pseudoprogress gotcha’ I’m not aware of, which makes this not longer an option, but on old cars you can check the alternator output with a cheap multimeter.

IIRC I “tune” my alternator belt tension to 14.0 volts output. You can also look for voltage drop across the charging circuit.

Most multimeters will measure 10A which should be adequate to check for parasitic drain when parked up

If you buy a new battery and your charging system isn’t working properly it may not last long

Edited by edlithgow on 22/05/2023 at 02:28