New battery time..which one please?

Jimyu · Post by **Jimyu** » Thu Dec 07, 2017 11:38 am

Having read a few old threads I'm confused. Its for a 2007 M Coupe which I believe came with an AGM battery but from what I've read is not required...

Can someone please tell me which battery to get!?

I see ECP have 34% off at the moment but they're telling me to buy an AGM one for £275 (before discount)

Wheras Tanya tell me to buy a non AGM for £73. Is this any good?
https://www.tayna.co.uk/096-Enduroline- ... P8383.html

I've noticed Costco sell Bosch batteries, but I've no idea if they are a good price, or which one I'd need.

Sorry, I'm clueless when it comes to electrics

ph001 · Post by **ph001** » Thu Dec 07, 2017 12:03 pm

I think the E85/E86 M cars came with an AGM battery as std AFAIK but there is no battery managment module fitted (IBS) so you can replace with a conventional wet cell type without issue. The Bosch Silver are a popular choice but basically any 096 style battery will fit.

The bottom of the range (but still good quality) would be something like this..
https://www.ebay.co.uk/itm/Powerline-09 ... Swvk9ZiDId

The Varta Silver calcium are a good step up in quality...
http://www.ebay.co.uk/itm/096-Bosch-Equ ... rmvSB=true

And the Bosch Silver S4 008 or S5 008 at the top (the S6 is the AGM but really not worth the expense imho).

I would put precedence on the CCA (cold cranking amps) over anything else.

Jimyu · Post by **Jimyu** » Thu Dec 07, 2017 12:18 pm

Thanks for taking the time to help

I put a Varta in my E46 M3 which has been good, so I will go for one of those I think

ph001 · Post by **ph001** » Thu Dec 07, 2017 12:25 pm

Yeh, Varta have a great rep. I might be tempted for the sake of £2.50 to go for the E44 which is directly comparable to the Bosch S5 (specs are identical) http://www.ebay.co.uk/itm/Varta-E44-577 ... xyOlhS1eLS

Jimyu · Post by **Jimyu** » Thu Dec 07, 2017 12:35 pm

Yes it's the E44 I have in the M3

Post by **srhutch** » Thu Dec 07, 2017 2:38 pm

I replaced mine with a standard battery. No point paying extra for AGM on a ///M E85/6

I bought a Bosch from the S4 series. Can't remember the model though.

Jimyu · Post by **Jimyu** » Thu Dec 07, 2017 6:08 pm

I went for the Varta E44 - shame prices have gone up 50% since I bought my last one 2 years ago though

ph001 · Post by **ph001** » Thu Dec 07, 2017 6:59 pm

Great choice

Lead prices have gone silly over last couple of years and the weak pound certainly aint helping.

dhobbs · Post by **dhobbs** » Thu Dec 07, 2017 7:45 pm

When you replace the battery, do you have to reset anything? Such as the radio or Windows one-touch?

ph001 · Post by **ph001** » Thu Dec 07, 2017 9:24 pm

Yeh, clock and windows are the usual ones. Simple enough.

Beedub · Post by **Beedub** » Thu Dec 07, 2017 9:31 pm

Stock AGM for me...

But understand this is expensive, they last a very long time as many are still using their factory unit.

nickw6666 · Post by **nickw6666** » Fri Dec 08, 2017 11:37 am

I thought that an AGM Battery was fitted by BMW to the Z4M coupe because the battery is located inside the car within the passenger compartment, and to reduce potential issues with battery venting gases inside the car, an AGM was fitted.

Not sure how critical this is, but would imagine that a faulty battery might emit some not so healthy gases into the car. If so not sure though how much an AGM battery would prevent this.

abar121 · Post by **abar121** » Fri Dec 08, 2017 11:38 am

Get an AGM if you leave the car for long periods. I fitted a Varta AGM batter a couple of years ago and the car is great.

I've tried new conventional vs AGM batteries on motorcycles and the benefits are really worth it.

TomK · Post by **TomK** » Fri Dec 08, 2017 12:08 pm

nickw6666 wrote: ↑
Fri Dec 08, 2017 11:37 am
I thought that an AGM Battery was fitted by BMW to the Z4M coupe because the battery is located inside the car within the passenger compartment, and to reduce potential issues with battery venting gases inside the car, an AGM was fitted.

Not sure how critical this is, but would imagine that a faulty battery might emit some not so healthy gases into the car. If so not sure though how much an AGM battery would prevent this.

No that's not true, there is a vent pipe which goes to the outside which connects to the battery.
Fwiw my stock battery (which was still fine when I changed it for something lighter a couple of years ago) was not agm, some cars seemed to come with them from the factory some didn't, I guess it's whatever they had lying around at the time as this was the time that stop/start was being introduced on e90 etc.
I don't think there's any technical reason to be buying an agm for these cars myself.

Mr Tidy · Post by **Mr Tidy** » Fri Dec 08, 2017 10:11 pm

Not a fan of AGM batteries personally!

My 123d with stop/start had one, and it needed replacing after only 4 and a half years and 55K miles! And because it had to be coded on the OBD it cost just over £250 in total!

Whereas my Z4C seems to have had it's first battery in 10 years last winter for around £100! It was an OEM one, which my local BMW Indy tells me is an Exide (not the Bosch I would have expected, but then the car was built in the USA).