Battery dead and won't charge?

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Warrior
Joined: Tue 11 May, 2010 10:02
Posts: 455

  Z3 roadster 3.0i

Battery dead and won't charge?

Post by Warrior »

Z3 3.0i automatic

I left the car a little too long so not enough charge in the battery - 6 years old, a Bosch S3 - to start her. Fixed up the charger (which i've checked is working ok) left overnight and it's now completely drained. Not a whisper.

Jump leads do nothing either. Dead as a Dodo.

Any suggestions other than buying a new battery?

137699
Joined: Wed 04 Mar, 2020 21:40
Posts: 21

  M coupe S50

Re: Battery dead and won't charge?

Post by 137699 »

Some chargers require the battery to have some residual charge before they can "detect" there's a battery connected - so won't charge a completely flattened battery.
You could try calling a recovery service and see if it will "jump" from their starter pack - might just be enough to kickstart the battery into life, though TBH at 6 years old & having been completely flat, it's never going to be the same again - may be easier to cut losses & buy a replacement.

You can get the better S4 Bosch batteries really cheap in Costco if you have membership, or know anyone that does.

petecossie
Joined: Wed 11 Apr, 2007 13:13
Posts: 150

  M coupe S50
Location: Billingham

Re: Battery dead and won't charge?

Post by petecossie »

If you are going after replacement battery and you don't have a Costco in your area, check your local motor factors. I was pleasantly surprised that I got an identical replacement battery- Bosch S4-007 with 3 year warranty - for £76 where as Halfords, Europarts etc had quoted over £100 for same or equivalent. The guy even put my reg in computer and came up with this battery I bought plus a range of other cheap options from £46 to £65.
Pete C

2000 Z3M Coupe - Cosmos Black Metallic/Black Interior.

Previous BMWs
2003 E46 M3 6 speed manual - Carbon Black/Black Interior.
2000 Z3M Coupe - Cosmos Black/Black Interior
1986 M635
1985 E28 M5
1983 E28 528i Alpina

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colb
Joined: Sat 05 May, 2012 22:46
Posts: 680

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: Battery dead and won't charge?

Post by colb »

Sounds like your battery is really dead, at 6 years best replace as the others have said, once installed and started put a volt meter on the terminals and check what the alternator is putting into it, you should see 14.5volts at best with engine running. Handy thing to have is a volt meter that you can plug in the cigarrett lighter to keep an eye on the charging rate. I did however fit permanent digital voltmeters to the dash of both my Z3 and Z4 both have integral usb power sockets which are handy for phone or satnav plugging in.
https://www.ebay.co.uk/itm/LED-Voltmete ... SwC99du4tS
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V

Warrior
Joined: Tue 11 May, 2010 10:02
Posts: 455

  Z3 roadster 3.0i

Re: Battery dead and won't charge?

Post by Warrior »

Thankyou all........i'll follow all suggestions.

I was hoping to get another few months out of the battery in the hope that Lockdown restrictions will be eased.

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