new battery fitted by BMW

simontaxi · Post by **simontaxi** » Thu Dec 08, 2022 7:43 am

Hi started to get slow cranking and time and date reseting on start up also radio muteing so got new bmw battery fitted on wednesday come to it today and its doing the same thing ! Any ideas guys ?

Greydog · Post by **Greydog** » Thu Dec 08, 2022 8:15 am

It would seem you have a parasitic drain or a Duff battery (rare but not impossible) Make sure there are no interior lights left on, after locking the car make sure it goes to sleep
My E53 it was the bonnet switch that caused issues had 2 fail currently all good, the E70 has behaved it's self so far

simontaxi · Post by **simontaxi** » Thu Dec 08, 2022 5:44 pm

Hi how do i check its gone sleep on my E70 2008 ?

Leslie · Post by **Leslie** » Thu Dec 08, 2022 6:36 pm

Starters can go faulty too and draw way too much current charge it up and see how fast it spins over , if its still slow its not the battery

How many miles has the car covered ?

X5Sport · Post by **X5Sport** » Thu Dec 08, 2022 6:56 pm

You’ll need to put a current clamp on the battery cable (a decent auto-electrician will have one). Starter current should not exceed 180A. I had the E53 one draw 900+A and the E46 about 500A. Both had starters replaced and were fine thereafter. Starter problems were common on both from 2004-6 but are rare on other years and later models.

Current clamp will also tell you the sleep current - should be as below. I’m not certain that there is a tell-tale lamp on the E70, but it used to be the ‘P’ mark on the gear.

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Fault memory should show which circuit is preventing sleep mode. I used to have a Road Angel plugged into the glovebox USB and got a wrist slap because it was keeping part of the system awake even when car off, and the fault log picked it up.

simontaxi · Post by **simontaxi** » Fri Dec 09, 2022 10:56 am

Leslie wrote: ↑Thu Dec 08, 2022 6:36 pm Starters can go faulty too and draw way too much current charge it up and see how fast it spins over , if its still slow its not the battery How many miles has the car covered ?

X5 has done 114000 i took it for a good run of 25 miles yeasterday and it was fine today but did a log of battery voltage was at 14.93v while driving with just radio on and heater blower on low ! i think that reading is abit high but will see how it goes .

Leslie · Post by **Leslie** » Fri Dec 09, 2022 6:23 pm

That sounds too high will be boiling the battery so best to get it checked out alternator regulator by the sound of it, there is an intelligent battery sensor too can go faulty I've heard but not quite sure how that would effect the voltage .

X5Sport · Post by **X5Sport** » Fri Dec 09, 2022 6:30 pm

Alternator voltage can be as high as 16V. If the battery is low it will be allowed (by the IBS) to higher - typically 14.8V. Unless you have a calibrated meter you’re only 0.13V out which sounds within tolerance, albeit upper end..

Worth keeping an eye on though. A fully charged battery should not need that much constantly. Did the supplier recode the car with a new battery? That might upset it.

simontaxi · Post by **simontaxi** » Sat Dec 10, 2022 10:14 am

X5Sport wrote: ↑Fri Dec 09, 2022 6:30 pm Alternator voltage can be as high as 16V. If the battery is low it will be allowed (by the IBS) to higher - typically 14.8V. Unless you have a calibrated meter you’re only 0.13V out which sounds within tolerance, albeit upper end..

Worth keeping an eye on though. A fully charged battery should not need that much constantly. Did the supplier recode the car with a new battery? That might upset it.

Hi yes car was coded with new battery i will log it this week and hope its ok !

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