05-04-2024, 12:52 AM | #1 |
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Normal battery Drain or Issue?
Hi Guys,
Just wondering if anyone knows or can point to some doco to say what is normal battery drain on a dual battery v8. After having the car sit locked for over a couple of hours, I can measure 200-300mA (0.2-0.3A) on the main battery. Is this normal? Had a couple of crank fails and no starts after the was sitting in a car park for like 30min-4hrs after a somewhat spirited 30min drive. This has happened on a couple occasion so am wondering if its just the battery dying or if I'm having and issue. Fires right up on a jump pack. The batteries are original from 2017, but I keep them on a tender if I am ever going to not drive the x for more than 2-3 days. Now it seems like it is struggling to survive over night. ISTA shows the battery charge % in the 80-90, and no charge issues, but fails to even crank the engine Haven't done any real diagnostics other than just checking on the amp draw. |
05-05-2024, 10:05 AM | #2 |
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See this video
Helped me see if the batteries are bad and need it replacement. I did buy one of those Solar Ba9 battery tester too.
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2017 Bmw X5 F15
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05-06-2024, 06:04 PM | #3 |
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That is an awful video, could be compressed down to like 2min. I have an AGM tester, but could not find it.
I think when I measured the current flow initially was just after I unplugged the charger and there was still some current flow. Gave it more time and now the current draw is in like 20mA. So low enough that my clamp meter is not longer reliable enough. Any general advice on a good DC clamp meter that can measure accurately in this range (sub 1amp), appreciated. But am convinced the battery is dead, I fully charge it through out the day. Unplugged it at night. After about 30min checked the draw, was down to 20-ish mA. In the morning, the battery was around 12.4 or 12.7 (cant remember) but it could not start the car. Jumped it, and cruised (on highway with cruise control for the whole way) for approx. 40min, parked for 30min. Tried to start and dead. During the drive, I could see the voltage was around 14.4-.7 so it was charging. Ordering 2x new batts. Last edited by Chilled; 05-06-2024 at 07:15 PM.. |
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