Is there a warning that the 12v batt needs replacement

ted99 · 02-25-2024, 09:23 AM

My 530e is approaching 5 years and so the 12v battery(s) could need replacement any time, now. Is there some warning from the car that the 12v battery is beginning to fail? I know that the automatic recharge from the HV battery extends the life of the 12v, compared to the ICE-only cars.

How does the failure of the 12v battery manifest itself in the PHEV's? I hardly ever run the ICE and never need the 12v battery to start the ICE first thing.

Has anyone replaced the AGM lead-acid battery with one of the LFP battery replacements now coming available? I know that the charging voltage is different for these.

Dephead2004 · 02-26-2024, 02:34 AM

My warning was the remote control giving a low battery warning! Tried lots of new CR2032 batteries to no avail. Eventually in disbelief followed advice here and on YouTube and replaced the 6.25 yr old battery. All back to normal.

Voltage readouts were 83% on old battery and 93% on new. A kwik fit test said battery fine but recharge.... I just had.

Hope this helps if a little weird

02-25-2024, 09:23 AM	#1
ted99 Lieutenant 242 Rep 535 Posts Drives: former i3>330e, 528i>X5>530e Join Date: Jan 2015 Location: Houston, TX iTrader: (0)	Is there a warning that the 12v batt needs replacement My 530e is approaching 5 years and so the 12v battery(s) could need replacement any time, now. Is there some warning from the car that the 12v battery is beginning to fail? I know that the automatic recharge from the HV battery extends the life of the 12v, compared to the ICE-only cars. How does the failure of the 12v battery manifest itself in the PHEV's? I hardly ever run the ICE and never need the 12v battery to start the ICE first thing. Has anyone replaced the AGM lead-acid battery with one of the LFP battery replacements now coming available? I know that the charging voltage is different for these.
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02-26-2024, 02:34 AM	#2
Dephead2004 Lieutenant 180 Rep 548 Posts Drives: G30 520i Join Date: Feb 2018 Location: UK iTrader: (0)	My warning was the remote control giving a low battery warning! Tried lots of new CR2032 batteries to no avail. Eventually in disbelief followed advice here and on YouTube and replaced the 6.25 yr old battery. All back to normal. Voltage readouts were 83% on old battery and 93% on new. A kwik fit test said battery fine but recharge.... I just had. Hope this helps if a little weird
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