Replacing batteries BMW onboard computer
Mark Gravens
into the PC board located in the instrument panel have died. The dealer tells
me the only thing to do is to replace the PC board at a cost of $400. I say
that's too much money for a couple of batteries.
I've removed the batteries and the markings are: " VARTA, Ni-Cd-Battery,
500 RST".
Can anyone tell me the specs on this battery? How many volts? Any
cross-reference information available?
The electronics store can't find this exact battery but has others designed
for auto computers. However, it appears that the voltages vary significantly
from 1.2 to 3.0 volts or so. What to do?
The instrument cluster was manufactured by VDO and all the boards have VDO
stamped on them. Any help will be greatly appriciated.
email to gra...@beachii.cerc.wes.army.mil or post here
Michael Zarembski
>I have a 1983 BMW 733i. The (rechargable?) Ni-Cd Batteries that are integrated
>into the PC board located in the instrument panel have died. The dealer tells
>me the only thing to do is to replace the PC board at a cost of $400. I say
>that's too much money for a couple of batteries.
>
>I've removed the batteries and the markings are: " VARTA, Ni-Cd-Battery,
>500 RST".
>
>Can anyone tell me the specs on this battery? How many volts? Any
>cross-reference information available?
The Varta catalog has the following:
Type 500 RST Order # 50750 201 052
Nominal Voltage 1.2V
Typical Capacity 575 mAh
Nominal Capacity 500 mAh
Discharge Current 100 mA
Charge Current (14 Hours) 50mA
I suggest you check with Varta (914-592-2500) for a dealer
Mike
Ian Boswell
says...
>
>I have a 1983 BMW 733i. The (rechargable?) Ni-Cd Batteries that are
integrated
>into the PC board located in the instrument panel have died. The dealer
tells
>me the only thing to do is to replace the PC board at a cost of $400. I say
>that's too much money for a couple of batteries.
>
>I've removed the batteries and the markings are: " VARTA, Ni-Cd-Battery,
>500 RST".
>
>Can anyone tell me the specs on this battery? How many volts? Any
>cross-reference information available?
>
>for auto computers. However, it appears that the voltages vary significantly
>from 1.2 to 3.0 volts or so. What to do?
>
>The instrument cluster was manufactured by VDO and all the boards have VDO
>stamped on them. Any help will be greatly appriciated.
>
>email to gra...@beachii.cerc.wes.army.mil or post here
>
>
>
>
You can replace the batteries if you are careful whilst taking the dash out.
The original batteries can often be sourced from electircla component shops -
try Radioshack for starters but expect to be given a "don't know sir". Ask
around and they may be able to suggest an alternative. (I'd love to help but
live in the UK)
Alternatively, if you know what you are doing with a soldering iron you can
use regular nicads - simply get a battery holder and solder it in with short
connecting wires in place of the original battery pack. This will only cost a
few dollars.
Ian
ps - if memory serves there is a description of the replacement process on the
BMW WWW page of the BMW NA club (run a search on BMW in Netscape)
Kevin McMurtrie
gra...@beachii.cerc.wes.army.mil wrote:
>I have a 1983 BMW 733i. The (rechargable?) Ni-Cd Batteries that are
integrated
>into the PC board located in the instrument panel have died. The dealer tells
>me the only thing to do is to replace the PC board at a cost of $400. I say
>that's too much money for a couple of batteries.
>
>I've removed the batteries and the markings are: " VARTA, Ni-Cd-Battery,
>500 RST".
>
>Can anyone tell me the specs on this battery? How many volts? Any
>cross-reference information available?
>
>The electronics store can't find this exact battery but has others designed
>for auto computers. However, it appears that the voltages vary significantly
>from 1.2 to 3.0 volts or so. What to do?
>
>The instrument cluster was manufactured by VDO and all the boards have VDO
>stamped on them. Any help will be greatly appriciated.
>
>email to gra...@beachii.cerc.wes.army.mil or post here
>
>
NiCd bateries are 1.25V per cell. The charging voltage varies a lot.
Before the failed batteries leak KOH on your $400 board, you may want to
visit Radio Shack and check out their batteries. The prices are too high
but they have a good selection and can order special types.
Marv Miller
First, gra...@beachii.cerc.wes.army.mil wrote:
>>I've removed the batteries and the markings are: " VARTA, Ni-Cd-Battery,
>>500 RST".
>>Can anyone tell me the specs on this battery? How many volts? Any
>>cross-reference information available?
Then, mcmu...@wco.com wrote:
>NiCd bateries are 1.25V per cell.
There's your answer. Carefully unsolder the battery, carefully cut the
outer plastic "shink sleeving" off, and count the cells.
Should give you a real good indication of the voltage required. The
physical size of the battery should be a good capacity indicator.
You might want to compare the bad battery to a computer's CMOS keep-alive
battery, too. It's probably doing the same job in your Beem'r as it is in
your PC. You can get them anywhere. And, yes, VARTA is one of the
manufacturers for the PC items.
--
Marv Miller
Reseda, CA, USA
ae...@lafn.org
JKirkman
the batteries have corroded enough to damage your circuit board. Cough up
the dough or live without it.