E89 Battery charging issue

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Ollie795

New member
Hi All,

Recently got my self a lovely E89 30i, I was checking things over on Bimmerlink and noticed under the battery section that the 'Battery state of charge' reading was about 48%, no problem I thought, I've been sat in it for a while checking everything over it's probably a bit discharged...
So I checked it again after a long drive (over an hour) and it was at 55%, I've checked it multiple times since and it varies between 50-55% never more...

Checked with Bimmerlink logging the generator output & battery voltage, the generator sits around 30-40 not varying much, UNLESS I let the battery state of charge drop to say 40% and take it for a drive then the generator output rises to 120-140 and brings the battery state of charge back up to the 50% region.

it's a 70Ah AGM battery, and the car does seem a little sluggish to turn over even when at 50%, I know it has a smart charging system on it, but is it not working correctly? From what I could find online it should control the battery charge to around 80%?
 
Probably a dead battery, probably caused by incorrect coding and registration.

You could try and re-code the battery and then reregister it and see what gives..

Most likely new battery time then code and register it pls!
 
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I’m assuming because it doesn’t show mileage second last battery replacement it wasn’t registered?
Or maybe not done properly?
Battery certainly takes charge and lasts a while even at a low state of charge so i’m holding out hope on it at the moment!
 
Ollie795 said:
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I’m assuming because it doesn’t show mileage second last battery replacement it wasn’t registered?
Or maybe not done properly?
Battery certainly takes charge and lasts a while even at a low state of charge so i’m holding out hope on it at the moment!
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Really bad move..high probability you’ll screw one of more of the EPS, EPB or FRM..amongst others
 
Ollie795 said:
i’m holding out hope on it at the moment!
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Just bite the bullet and buy a new one, it’s not worth risking a tired battery on the E89, they are just too sensitive to voltage fluctuations, instead of a £120 battery you could be looking at potentially thousands diagnosing and fixing blown modules, the EPS is essentially susceptible to low voltage.
 
I've had similar recently, need to check what it is at the moment. Runs ok. I think especially my car needs a good run like a few hours drive. Not the 20-25 minute to work and back. Also stopped leaving headlights on and use the auto light function.
 
Something strange, when i tried to charge at the points under bonnet, my Halfords intelligent charger said charged after 15 minutes.
I didn't believe, so put charger direct to battery, 3 hours later still charging so left overnight to charge.
I wondered if the ibs was faulty.
Be interesting to charge with pos. on battery and neg. to earth near battery.
 
flybobbie said:
Something strange, when i tried to charge at the points under bonnet, my Halfords intelligent charger said charged after 15 minutes.
I didn't believe, so put charger direct to battery, 3 hours later still charging so left overnight to charge.
I wondered if the ibs was faulty.
Be interesting to charge with pos. on battery and neg. to earth near battery.
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Have you done a residual discharge current check?
 
Charged after 15 minutes when it's clearly not - RED FLAG.
Showing 40-50% health - RED FLAG.
Unknown age? RED FLAG

Battery on these is a maintenence item - just get it changed & registered. Write on the top the date.

Change again in 5 years.

Thank me later.
 
I need to do a long journey, at least an hour. Checking daily % it is going up providing i drive every day and not let it sit for 2-3 days using another vehicle. Battery is not that old, just over 3 years.
Another thing i need to do is insulate the battery.
Sitting in a cold boot with it's base on cold metal doesn't help.
Even sheet of cardboard would make a difference.
Was a time all batteries sat in engine compartment.
 
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Just a note, the last 2 batteries i fitted were Halfords advanced AGM (i think Yuasa make), seems i still have previous at work.
It's showing 3 volts!
Both lasted 3 years before giving problems (might be coding problem though).
Interestingly (or not) i have a old wet lead acid Gill aircraft battery about 3 yrs old, stood next to it for a year since it was replaced.
Volts on that 12.1. (Was replaced in error, was a loose cable).
Sometimes aircraft are stood for months before being started.
Perhaps we should fit aircraft batteries, but cost twice as much.
 
flybobbie said:
Just a note, the last 2 batteries i fitted were Halfords advanced AGM (i think Yuasa make), seems i still have previous at work.
It's showing 3 volts!
Both lasted 3 years before giving problems (might be coding problem though).
Interestingly (or not) i have a old wet lead acid Gill aircraft battery about 3 yrs old, stood next to it for a year since it was replaced.
Volts on that 12.1. (Was replaced in error, was a loose cable).
Sometimes aircraft are stood for months before being started.
Perhaps we should fit aircraft batteries, but cost twice as much.
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Fundamentally different situations…once the aircraft is switched off there are no residual / parasitic drains unlike modern cars ..

If you’re batteries in the E89 are only lasting that long you have intrinsic faults in the car
 
Well wondering when the last Halfords was purchased. Must now be 4 years old. Last Varta with similar spec. went on another vehicle.
I put the old battery on charge. Been on 6 hours and still charging.
Want to see if it's any good and if it holds a charge
True aircraft batteries are isolated from any residual drain other than winding those mechanical clocks..
But should be able to leave car few weeks without battery problems.
Too much going with these modern cars.
Strange no sooner battery fitted my boot light has gone out?
Wondering if the boot motor wires have broke again or a short draining battery.
Did suspect if the MMI or amp i fitted wasn't switching off..
 
Well battery now consist charge in the 80-100% range.
Seems once the battery over say 4 years, still work but tired.
 
flybobbie said:
Well battery now consist charge in the 80-100% range.
Seems once the battery over say 4 years, still work but tired.
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Many cars had their original batteries for over 10 years…short life spans are due to mismanagement in some form or another..
 
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