Discussion
Hi
I have an electrical fault on my BMW i put a new batterie on the car, and over night it drains it to 25% so the car could not start
what would be the cause, their must be a drain on the system some where, when the car is turn off. no lights where left on, so I'm thinking the factory fitted alarm ? any thoughts
I have an electrical fault on my BMW i put a new batterie on the car, and over night it drains it to 25% so the car could not start
what would be the cause, their must be a drain on the system some where, when the car is turn off. no lights where left on, so I'm thinking the factory fitted alarm ? any thoughts
Have you checked the light in the boot and the glovebox - known problems (easiest to just remove the bulbs). Also, the wiring harness from the boot to the boot lid is known to wear, causing shorts.
Failing that, disconnect the battery completely to check it isn't faulty (just because it's new to you doesn't mean it's new to where you bought it from).
Failing that, disconnect the battery completely to check it isn't faulty (just because it's new to you doesn't mean it's new to where you bought it from).
A few questions.
1) What E36 is it? What options does it have on the face of it?
2) What size of battery is in there and what brand?
3) Have you attempted to charge it up until fully charged and seeing if the same results occur?
4) If you have a multimeter, have you put this in series with the keys out of the ignition to see what parasitic drain you have?
5) What makes you think it is down to 25%? The voltage, or do you have a battery tester?
FWIW alarms can be a issue but something like a light staying as as said would have a similar effect, especially now where batteries won't quite have their full cranking power due to the lower temperatures.
We bought an Exide Premium for one of the Mondeos as the stock battery decided it would only have half of its capacity at best. Put the new one it at similar temps to now and there was no real difference. It took a charge until fully charged up on the CTEK for it to be reliable when cold. That was a brand new battery too from ECP. I did test it with a capacitance tester however to ensure the battery was not a duffer ; A load tester would give a similar result but in a different way.
1) What E36 is it? What options does it have on the face of it?
2) What size of battery is in there and what brand?
3) Have you attempted to charge it up until fully charged and seeing if the same results occur?
4) If you have a multimeter, have you put this in series with the keys out of the ignition to see what parasitic drain you have?
5) What makes you think it is down to 25%? The voltage, or do you have a battery tester?
FWIW alarms can be a issue but something like a light staying as as said would have a similar effect, especially now where batteries won't quite have their full cranking power due to the lower temperatures.
We bought an Exide Premium for one of the Mondeos as the stock battery decided it would only have half of its capacity at best. Put the new one it at similar temps to now and there was no real difference. It took a charge until fully charged up on the CTEK for it to be reliable when cold. That was a brand new battery too from ECP. I did test it with a capacitance tester however to ensure the battery was not a duffer ; A load tester would give a similar result but in a different way.
Edited by SebringMan on Wednesday 28th February 19:45
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