Door/tail open battery drain

[caseyjay]

I am installing a rear view camera/Android tab and have drained the battery several times. A trickle charge sets it right again. Now I've completed wiring etc I was testing camera setup, maybe 15 mins of tailgate and door open, a few ignition on/offs. Drove the car 2 hrs later for 2 mins, shut off and click click when I went to restart.

No idea how old the battery is and under normal load/usage it works fine.

Are the X5 electrics pretty sensitive? Is there a circuit drain with door open and lights off? How long should you be able to keep in acc mode/door open and preserve cranking power?

[g300d]

Have your battery tested first. You may just have a dying one that does not hold a charge as well anymore.

It's not always the case of course but it is the easiest to check. I've gone on an exhaustive search for battery drain circuit by circuit, found nothing, and have a new battery fix the problem lol! Like in your case, it would work fine most of the time but would go flat at random.

[g300d]

Oh and yes, X5 electrics can be sensitive...there have been lots of cases of module errors and running problems caused by slightly low voltage from marginal batteries and alternators.

Engine off and key in ACC position for a reasonable time should not drain your battery. Some X5's even have auxilliary cabin vent systems/heaters that can be programmed to run engine off via batt power alone, so they have a large capacity when everything is working as it should.

Ive had the X door open and key in ACC a few times for similar or longer periods when working on stuff and it would start right up.

[caseyjay]

I tried the OBC battery test - 13.5v when driving, 11,5v when I come to a stop but oddly restarted and drove again. Came home and did the 5 mins with main beam on/engine off test, now drops to 10.4v and no start.

Am guessing I've been lucky so far it's not stranded me already.

Now I need to take a trip this weekend and will be away > 1wk. Normally I'd buy online but not going to receive it in time.

Either I buy local now - Fulmen/Exide
or
I go with my battery charger/leads and wait until I can get a 'better' brand.

What would you do? It's my first BMW, normally I'd buy Bosch for my Audis, not sure of Fulmen? Any views?

thx

[SlickGT1]

I got mine at advance auto, with coupon code. I believe it was AGM or something. Direct replacement. Perfect for a year so far.

[g300d]

A healthy alternator is normally able to give above 13v at idle.

The above results would make me want to check both battery and alternator.

[TiAgX5]

Originally Posted by caseyjay

I tried the OBC battery test - 13.5v when driving, 11,5v when I come to a stop but oddly restarted and drove again. Came home and did the 5 mins with main beam on/engine off test, now drops to 10.4v and no start.

Am guessing I've been lucky so far it's not stranded me already.

Now I need to take a trip this weekend and will be away > 1wk. Normally I'd buy online but not going to receive it in time.

Either I buy local now - Fulmen/Exide
or
I go with my battery charger/leads and wait until I can get a 'better' brand.

What would you do? It's my first BMW, normally I'd buy Bosch for my Audis, not sure of Fulmen? Any views?

thx

Driving with a dead battery will cause alternator/regulator failure.

A new battery will be 12.7 to 12.9v (100%), 12.2 is 50%, 11.7 is 0% (dead!). Charge the battery overnight, turn on headlights for 30 secs, then check voltage.

Many BMW owners replace the battery when the result of above test shows 12.2 (50%). This increases alternator/regulator life & avoids false trouble lights.

[caseyjay]

Originally Posted by trader4

You mean it has 11.5V when the car is idling, but not moving?

No I had the IBC on test 9 and 13.5v showing when driving, but when I turned everything off it dropped to 11.5v.

Have tested more today and regularly holding 13.4-13.6v when running so am hoping alternator is ok.

Not too sure about my battery charger though - only has 2 settings - 0-20Amp (marked for bikes) and 15-60Amp (marked for cars). Had it charging overnight on 15-60 and only reached 12v this morning so guessing dead cell.

Will check date on battery.

Is this something I should replace immediately or can it wait a week of further usage whilst awaiting delivery...?

[TiAgX5]

I wouldn't drive it if resting voltage is below 12.volts.

Could cook a diode in the regulator.

[caseyjay]

I think I might be more in need of a new charger - I left it charging overnight >12 hrs on the lowest 0-20amp setting, and after 1 min with headlamps on got 12.6v. Drove it for 30 mins and tested again, seems stable now. Will keep an eye on it though thx