Battery dying? or something else more expensive

[PDJ]

So I serviced my car, cleaned it , generally got it ready for the summer and taxed it

It developed a voltage drop from the battery over a short period of time I put this down to the car not been run for over 6 months I charged the battery up or used my NOCO booster starter ( this is very good)

It also through up loads of fault codes most I have seen before but a few new ones the ABS light and the brake light in yellow these went out after resting the code plus it needed a short drive 200meters

So I thought alls good

Today I drove to watch some cycling when restarting the car it turned over in a laboured manor but started each time while I was out

when I got home I read the codes as the last time it started the ABS and brake lights stayed on for the drive home I lost the hill assist so probably the traction control as well but did not push it to find out as not used to it and the roads where damp/wet

As I was sat reading the codes and resetting them I only had the ignition turned on the radio and other things turned off the battery dropped from the 12,4v to 10.2v and the car refused to start it is now sat with a trickle charger connected to see if that sorts it out

The battery is a Bosch fitted 05-05-2020 over the winter the battery had gone flat a few times I am hoping that it is just a new battery required but the ABS and brake lights are a little concerning

Any ideas

[Joez4]

Once a battery goes flat it usually won't recover, if you have a noco trickle charger you can do a repair procedure on it, didn't fix my battery but a new battery fixed all my problems until the alternator gave up, you'll get codes tho if the alternator is at fault, if you do try the repair procedure then disconnect battery from the car as the high voltage it puts into the battery could damage modules on your car

[Rockhopper]

Yep, your battery in knackered I'm afraid. They don't take kindly to repeatedly going flat. Even going flat once and being left for a few weeks could be enough to kill even a new one.

[Mr Tidy]

It sounds like your battery is beyond salvation sadly.

When mine was on its last legs I got the dreaded trifecta appear after I started it with a jumper pack.

Ross at RBM managed to clear them by resetting the steering angle sensor, but BMWs of this age can throw up all sorts of random lights and codes when the battery is low.

[j3nks79]

Get the multimeter on it when the car is running and see if your alternator is putting out 14.1V.
If it is then your battery is knackered. Or you have a parasitic drain.

[PDJ]

My mate had an old school battery tester so we tested it off the car it died, so he lent me a battery to run around with, found the old receipt and it was 05-05-2020 looked on euros web and it has a 4 year warranty (now) so went in asked and handed the battery over he tested it and yes its dead 5 mins latter and a form filled in, I have a new battery but it only has 3 weeks warranty as per the old receipt (that how it is other wise you could have a battery for life)

[Mr Tidy]

Well at least you got a new battery under the warranty, which has to be a result even if it is only guaranteed for 3 weeks!

Keep it charged and you should get years out of it.