What is the best battery to buy

[Grommit]

I want to replace my battery before the winter sets in.
Given the X5's propensity for electrical problems I would like to fit the biggest battery possible particularly, in terms of AmpHours. Also what is the biggest size that will physically fit?
Are there any tricks or tips to avoid causing problems with the electronics, I have read of quite a few here caused by changing the battery. I was thinking of connecting a battery charger to the under bonnet connections to maintain the voltage while I swapped the battery out, good idea? or not?

Thanks

[X5Sport]

Most Owners seem to go for a Bosch S4, S5 or S6 series batteries.  The number indicates the length of the warranty.  They are AGM type rather than liquid electrolyte so don't 'slosh'.  You need to bear in mind that you need to stay within the limits of the alternator in order to be able to keep the battery fully charged.  Fitting too large a capacity battery will give you issues.

I had an S5 on mine which was the same size as the OEM battery and once I'd dug into the boot to get at it, took about 5 mins to change.  I think the S5 had a 830CCA starter spec and 100AH rating

I disconnected both sides or the battery and touched the leads together to eliminate any charges anywhere.  Never had any issues on reconnection other than the common DSC/ABS lights which go out as soon as the steering is moved lock to lock.  I had the battery off several times and never had any troubles.

Our E46 had the battery changed by a Dealer and it did some damage though we suspect the mechanic fitted it in reverse polarity as some very large (30A) fuses were all blown.  They fixed it free and never told us what they got wrong.

Remember to keep the gas vent line and reconnect it.  If you don't use it then you can get acidic condensate in the battery box which does not mix well with steel.

Richard

[Denis O]

Popped 1 of these
http://www.eurocarparts.com/ecp/c/BMW_X ... d8e&000020
on mine back in July after returning from 3 months travelling and finding the car with zero power. It was on the original BMW battery so not bad for 7 years.

Once fitted it fired up immediately.

I've since changed my Z4 and Defender batteries for the same BOSCH S4's and all is good.

[jaynana]

Bosch S5 all the way.

search ECP for a discount code which should get you the battery for under £90.. if those codes still exist.

no issues about disconnecting the battery as far as electronics are concerned, as long as you do a clean disconnect/re-connect i guess..

[Horizon]

There are more than one type of S5 you want the Bosch S5, 019. 100ah

[Grommit]

OK Guys, thanks very much for that, I shall order one today.

[Dimsum]

£112.32p on ECP using discount code battery20

My alarm keeps going off in the middle of the bloody night. Can't see any other problem so i'm going to replace the battery and see if that helps..

[Drpellypo]

Try batterymegastore.

[X5Sport]

[quote="Dimsum"]
£112.32p on ECP using discount code battery20

My alarm keeps going off in the middle of the bloody night. Can't see any other problem so i'm going to replace the battery and see if that helps..
[/quote]
Have you checked the bonnet switch?

R

[Dimsum]

Hi

No, is that a likely culprit then? It started a few months ago and seems to come in spats. . Last night was twice. Last week twice again and about 6 weeks before that.
Would the bonnet switch cause the alarm to go off all the time or occasionally like mine?

Sent from my GT-I9300 using Tapatalk

[Sanj]

Disconnect it now (unclips in seconds). Wait and see.....

Bet it's the switch.

[X5Sport]

If the contacts are going bad then it could be a cause and an intermittent one at that.  Mine went bad after about 5 years and needed replacing.  Disconnect it.

(And Sanj is stalking my posting........ :blink:)

Richard

[Dimsum]

Thanks guys

It seems a cheap part so I will replace that first..

[marko]

re: the alarm going off. This has just happened to me. going off for no reason. My BMW mechanic buddy checked it and disconnected the bonnet connection and it hasn't gone off since. Just need to order an new switch now 

[mennie]

If you really want to know if your battery is broken... measure the Voltage level...
I replaced mine a month ago with the Bosch S5 019 100Ah.

You can see the Voltage through the instrument cluster (search Youtube for a video).
Or connect a multimeter to the battery.
The battery is under the spare tire and under the air compressor, takes some digging to get there.
Don't forget to connect the vent tube on the left side and plug the right side hole (plug is provided with the end caps).