Changing a Battery

zom247 · 8 May 2020 at 10:41

The battery is about ten years old now and was flat a couple of days ago. I jumped it and it started ok, left it running then had a bit of a drive round. Yesterday it started fine and had another drive round the area. Today it turned over then just died again. Due to the age of the battery I think it's perhaps time to buy a new one and fit it myself, never changed a battery before but looks pretty straight forward (famous last words!).

Is it worth changing the battery now during lockdown? We have 2 cars and only use them about once a week when we go shopping. Is there anything I need to be aware of when changing the battery (stereo codes?) or is it just a simple swap?

Thanks.

Merlin5 · 8 May 2020 at 11:29

It's easy changing the battery. I'm not at all handy with cars but removed my battery for the first time ever yesterday. If I can do it anyone can!

If you've got a socket wrench, it's the 10mm socket you want. Undo the negative terminal first followed by the red positive terminal. Then unscrew a couple of screws holding the bracket that's holding the battery in place and lift the battery out. Just be careful to make sure each terminal you disconnected doesn't touch metal on the car, wrap each one with a cloth. New battery in, put on positive terminal first, than negative. So basically, start with the negative and finish with the negative.

MrRockliffe · 8 May 2020 at 11:31

Whenever I’m working with the battery, I use a bit of cardboard under the terminals to stop them coming in contact with the body of the car - handy if you’re doing it by yourself :-)

jpaul · 8 May 2020 at 15:44

a bit of a drive arround may not have resurrected it ... refer to battery charger thread ?

[disconnect/remove negative first, just avoid shorting +terrminal as you do it,
then positive , it doesn't matter if you short with chassis, at that point, because neg was disconnected ...
maybe if a car has two batteries , like the transit , in charger thread, you have to take more care ?]

BUDFORCE · 9 May 2020 at 14:51

Ten year old battery has done well.

Yes change it.

Don't drop your socket or whatever your using across the terminals

stoofa · 9 May 2020 at 18:20

Just make sure you don't need to have a new battery coded in. VAG cars for example, sure the physical battery swap is fine, however the new battery needs coding in as well.

Fluke? · 9 May 2020 at 19:55

I did mine the other day. I had to order an extension bar to get access to the bolt by the side of the battery. And then another extension bar because idiot boy here didn't realize there were different sizes and hadn't got a 3/8" extension bar.
Every day's a school day ey. lol.
Got the battery itself from eutocarparts. So much cheaper than halfords etc.

Thinking about keeping the old battery and buying a cheap charger to rig some 12v lighting into my non connected garage.

oh, radio was fine in my little sportka. Just had to reprogram the channels etc.

zom247 · 10 May 2020 at 13:42

Changed the battery and all good now. Pretty straight forward to change, hardest part was trying to remove the plastic case over the battery as third catch was behind some wires which I was trying not to damage. Started first time and felt better to drive, my first battery change in over 30 years of driving

zom247 · 10 May 2020 at 13:51

Another question, there's a small red plastic plug on the side of the battery. Does this stay in or need removing?

zom247 · 13 May 2020 at 07:18

zom247 said:
Another question, there's a small red plastic plug on the side of the battery. Does this stay in or need removing?

Can anyone tell me whether I need to remove this plug or not? I believe it's a breather plug but not 100% sure

Malt_Vinegar · 13 May 2020 at 07:57

Remove them, they are there to stop electrolyte leakage during shipping I believe, but should be removed when installed as it's part of the batteries safety system should an accident happen and the battery is damaged

jpaul · 13 May 2020 at 08:47

battery before last (3series) had a flexible breather tube from its top, that you poked through a grommet, to the outside, at base of battery tray. ...
out of fashion now ?

Meaker · 13 May 2020 at 09:58

With sealed batteries yes.

jpaul · 13 May 2020 at 13:13

edit: are any batteries really sealed .. maybe you cant top them up, but they can relieve pressure, like the tube did

R4@1 edmund king aa president ... 50% of call outs battery problems ... so, buy some shares in varta/bosch.

I guess twitter does not discuss car maintenance

Invertigo · 13 May 2020 at 15:11

jpaul said:
battery before last (3series) had a flexible breather tube from its top, that you poked through a grommet, to the outside, at base of battery tray. ...
out of fashion now ?

BMWs have a breather pipe that should be connected to the battery breather, as the batteries are technically inside the cabin on BMWs (In the boot, usually). This pipe vents to the outside, so any off-gassing that may occur in the battery, however unlikely, doesn't lead to gases being trapped in the boot. With a battery in the engine bay its not a concern as the airflow through the area removes anything.