Battery woes continue

[1BimmerNut]

Help. Finally bit the bullet and bought a quality VARTA battery for my 135. $500! Had it professionally installed and coded. Drove the car a lot straight after so should have had a good charge over a few days.

Left it for a week and went to start it and got the same problem again.

You put the key in, hit the brake, push the button, xenons come on then go out and nothing. Play around for 5 mins and finally get a start.

I will remove my ipod in desperation - anything else to try? I haven't taken my car to a dealer to see if I need that battery lead recall.... wonder if that would fix it???

[1q2w3e4r]

Sounds like something is draining the battery to me.

[1BimmerNut]

Originally Posted by 1q2w3e4r

Sounds like something is draining the battery to me.

Not sure - Last battery I tried a battery keeper and actually had the same thing happen straight after a charge. That was when I believed the battery had died so I replaced it. Car only done 24000kms so shouldn't be wear-n-tear. If I drive it I have no probs. Will check the alternator is charging next.
My only mods are Angel eyes and a JB3+PNP which I took out to see if that's causing a disturbance in the electrics - yes I know unlikely

[david.orr]

Originally Posted by 1q2w3e4r

Sounds like something is draining the battery to me.

Agree. Fuel pump usual culprit?

[Dackelone]

So whats the battery voltage when this happens(at the battery terminals?) And whats the voltage at the battery when the engine is running?

[1BimmerNut]

Originally Posted by Dackelone

So whats the battery voltage when this happens(at the battery terminals?) And whats the voltage at the battery when the engine is running?

This is after 2 days of not starting - removing Iphone/ipod and JB3+ and locking car.

12.46 boot unlocked
12.28 car unlocked and voltage coming back up/recovering
11.25 just after start (no probs kicked first go)
Running 14.93 up to 15 at fast idle

[Dackelone]

Originally Posted by 1BimmerNut

This is after 2 days of not starting - removing Iphone/ipod and JB3+ and locking car.

12.46 boot unlocked
12.28 car unlocked and voltage coming back up/recovering
11.25 just after start (no probs kicked first go)
Running 14.93 up to 15 at fast idle

Looks like a bad battery buddy. Min (DC)voltage should be at least 12.8V standing. Anything less and the battery isn't fully charged or its bad.

With your engine running your measured voltage looks a little bot high. Normally you should have 13.8v or 14v max. You might try measuring for AC VOLTS across the battery while the engine is running. Anything more than ONE ACvolt and your alternator could be shot. Or more so the voltage rectifier on the Alternator.


I used to have a Tech who worked for me say...
"...Just because its a new part don't mean its a GOOD part!"


Go back to your dealer and have them give you a new battery. And make sure they code it to your car properly. Maybe you got a new tech who did not code it properly. Or maybe you just got an old battery from their parts inventory. Every battery will have a manufacture stamp on the top side of it. Maybe check that date. ?

G.L.
Dackel

[1BimmerNut]

Went to the city today 40 mins each way - got home and with a running engine charging was at 14.8v engine stopped 12.8v
Isnt it a feature of the car that the computer ups the charge rate if needed - thought that was the idea of coding the battery that there is monitoring of the battery condition
Will check date of battery but fitted by a BM expert who runs his own show - alternative is take it for a run during the week

[JinAM]

It can't be the battery. Unless you put another power source to it, the more you try to start it, the less charge it will have. It will not magically find power and start the engine.

[Kiwi Peter]

Originally Posted by JinAM

It can't be the battery. Unless you put another power source to it, the more you try to start it, the less charge it will have. It will not magically find power and start the engine.

Caaarmon its a BMW they are fantastic, hey its made in Germany so it will never break down or cost much to fix if it does

[flinchy]

Originally Posted by Dackelone

Looks like a bad battery buddy. Min (DC)voltage should be at least 12.8V standing. Anything less and the battery isn't fully charged or its bad.

With your engine running your measured voltage looks a little bot high. Normally you should have 13.8v or 14v max. You might try measuring for AC VOLTS across the battery while the engine is running. Anything more than ONE ACvolt and your alternator could be shot. Or more so the voltage rectifier on the Alternator.


I used to have a Tech who worked for me say...
"...Just because its a new part don't mean its a GOOD part!"


Go back to your dealer and have them give you a new battery. And make sure they code it to your car properly. Maybe you got a new tech who did not code it properly. Or maybe you just got an old battery from their parts inventory. Every battery will have a manufacture stamp on the top side of it. Maybe check that date. ?

G.L.
Dackel

Should necessarily be bad if it's not at 12.8v, there's usually a range.. not sure on this one as i don't have the specs handy, but the big lead acids at work have a huge range they'll be happy to continue operating on, before collapsing at ~8v. - non charging load they drop from 12.xV to 11.9v and down from there pretty rapidly.

Unloaded they'll sit on 12.5 or so, then load hits them down to low 12's, then down from there to mid-high 11's.. then they 'bounce' back up near 12, the healthy ones to 12.1 or 12.2, then taper

only way to really tell would be to do a discharge test, load up the battery with no altenator and see how the voltage drops... if it's bad, it'd probably go 12.x>11.9 and within 5-10 minutes collapse to <<<10v