E86 flat battery

J

Jay-Z4

Member
Yesterday I got back home after being away travelling for a month. I tried starting up my Zed but the battery was completely flat. I got out the jump leads but that didn't give it enough of a boost. Called RAC to give me a more powerful boost and this did the trick. Took her for a spin and noticed every time I went off the accelerator all of the warning lights appeared. I then noticed the steering had gotten much heavier as if the power steering had given up. Carried on driving for half an hour then left her idle for another 30 minutes. Turned ignition off, went inside for a short while, came back out and the battery was flat again!!!

Is this simply a case of needing a new battery or could there be more to it?
 
I would try that first. They suffer with all sorts of electrical problems when the batteries are on there way out. I would try a new one but check the ground point in the boot to. Give it a clean up while your at it.
 
My original battery (May'03) started acting up when I stopped using the Zed as a daily driver back in January. Eventually wouldn't hold any charge at all even after being on charge overnight. Fitted a new Bosch S4 and everything is fine again. The Bosch is also considerably lighter than the original BMW battery. :thumbsup:
 
Once a battery has discharged it will never be the same again, get yourself a new one and a battery maintainer if you plan on going away for a while again.

I got a Varta E44 online for about £60, been very happy with it.
 
Anyone using a Solar trickle charger?
I won't be using my car for long periods of time due to travelling for work etc and have had battery's go flat before.
So it would be nice to pick up a good trickle charger if recommended...?
 
A proper battery maintainer is better if you have access to mains. Solar is better than nothing followed by simply disconnecting the battery.
 
Was going to create another post but looks like this may cover it.

The Z4 has the now privileged position of being a weekend only toy, as such misses out on regular driving - coupled with a few recent holidays abroad in in the other car - the battery is flat.

I have a solar charger, FWIW it's not enough to bring a battery to life (i don't think that's a surprise to anyone though). This will be used to maintain the battery going forward when it's not tucked away with a CTEK.

Turns out the ///M needs quite a bit of battery, both my neighbours portable chargers weren't sufficient to kick it into life - the car just ate their charge for breakfast and gave me some ignition power for a few seconds :D made me laugh. Thankfully a C63 needs a small power station to turn it over so it has a huge boot battery and can happily boost the Zed into life.

The problem?
The Zed makes it about .. 10-15mins of driving before conking out (throughout which the odd random dash light flashes occasionally. i suspect due to a lack of battery power). So either the battery isn't holding a charge (whatever little charge it gets whilst hooked up to the C63?) or the alternator can't charge it, or isn't charging it? I don't have voltmeter lying around sadly, any other way i can figure out which is the problem? A decent battery i can buy myself, an alternator involves towing the car to BMW Park Lane and bending over to receive whatever bill they deem fit. I'd rather make sure it's not the former first?
 
You can get a cheap multi meter for about a fiver, I'd invest in one to find out if the alternator is outputting any current. :thumbsup:
Rob
 
Tested the batt, a meagre 1.972V and a healthy 14.2V when engine is running suggests to me it's the battery! not a bad innings for 10 years i guess.

Any recommendations for battery? Bosch S4/S5/S6? Not fussed about price, just whatever is best.

Needs to fit the M boot mounted bracket so not sure what size it should be.

JB
 
Found this post:

http://www.z4-forum.com/forum/viewtopic.php?f=9&t=46118&hilit=battery+agm

Whilst it does highlight we should probably be using AGM batteries it doesn't seem to be a definitive answer.

One suggestion they need to be coded and one that they do not - not much of a quorum! Maybe batteries are not a hugely thrilling topic to debate :D
 
Agm is just the battery technology, I'm not sure that agm means only use for start stop else I'm buggered!

I just put a Bosch s5a08 in mine, all is good so far.
From a size perspective it fits into the smaller length battery clamp position at 278mms, I think the larger clamp size is more like 312mms or thereabouts. (Best give it a measure to confirm if you go for a bigger battery size).
Height and width are ok.
 
Hi, If you have a Coupe, you can get a slightly larger battery that fits perfectly because the ragtop has a bigger battery to accommodate the roof mech. I went to Motobitz and got some advice and it cost about £120 but its worth getting a decent battery.
 
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