Radio Battery Drain

[Mordan]

Hello,

After 3 days in the garage, my car would not start. With a multimeter, i start debugging. In 12h (overnight) I lost 0,3 Volt, from 12,6 to 12,3.
Then I measured the current leak. With the radio plugged, i have 164-180 mA leak, without the radio I have 34 mA.
Does that mean this 100 dollar peekton radio is draining my battery in STAND BY MODE?

I can't believe my radio takes 140 mA alone. What a bunch of retards.

[pingu]

Your car radio does seem to take a retardedly excessive amount of current (is that really just standby current when the radio is off?).

But I also wonder if your car battery is up the creek. With the radio drawing 170mA, you'll be losing about 4 amp-hours of charge per day. Even if the radio wasn't being a shitbag I'd expect the car battery to be able to lose 12 amp-hours (i.e. after standing for 3 days) and still be able to start the car.

One catalogue suggests that the 325 has an 85Ah (amp-hour battery) so the battery ought not to be fazed by losing just 12Ah of charge.

[whiskychaser]

IIRC Bentleys says you should have a max drain of 100ma. I think that must be with a mechanical clock-mine doesnt draw anything:) While its not a BM, my father's car had the same symptoms and that was down to the radio too. Auto electrician sorted it-they just left the fuse out until he got a new radio. That was a couple of years ago and its still on the same battery

[525i winter driver]

is it possible the accessory lead to the radio is connected to an 'always hot' circuit? i don't know about the european setup but i found the radio wiring to be quite difficult.

[whiskychaser]

is it possible the accessory lead to the radio is connected to an 'always hot' circuit? i don't know about the european setup but i found the radio wiring to be quite difficult.

A lot have a perm. live to keep the power to the memory chip so you dont lose the security code when you switch off. There must be a fault somewhere thats allowing that live to get across to another circuit. If its getting to an output tranny that could enough to drag a battery down. You can get adapter cables to convert most radios to/from ISO so you dont need to use choc blocks any more:D

[Mordan]

Your car radio does seem to take a retardedly excessive amount of current (is that really just standby current when the radio is off?).



ISO connected radio yea. It is easy to remove and I tested the current drain with and without the radio plugged in to the ISO connector in stand by, with and without the face of the radio.

180ma drain with the ISO connector plugged.
34ma drain with the ISO connector unplugged.