From digest.v4.n609 Thu May 16 20:40:47 1996
From: BMW_at_comet.net (Bavarian Motor Warehouse)
Date: Thu, 16 May 1996 22:25:21 -0400
Subject: <E34 M5> Re: Probably need battery
>In the meantime, what batteries can I choose from for my '91 E34 M5
>(battery under the back seat) that won't require a second mortgage?
The new BMW replacement batteries are made in the US by Douglas. I'm told
there are only 3 battery manufacturers in the US, Douglas, Exide, GNB.
Probably not accurate, though. Sam's Club sells a Mercedes Diesel battery
from GNB which I believe will fit your car but is not vented through a
tube. I'm told (I listen well) that GNB offers a vent kit consisting of a
cover for the cell cap well and a tube but have not seen it. I think their
phone # is printed on the batteries at Sam's. Interstate Batteries sell an
E34 battery which has a funky oval vent at the center of one long side and
also offer a tube and adapter to fit the factory under-seat vent pipe.
Should cost about $100 with the adapter. Interstate sells through
dealers/independent shops. Please, on all applications where the battery
is in the trunk or under the seat, use only a vented battery or battery box
The real problem is on E30 fitments, as the group 41 battery Sam's sold for
the E28 used to fit fine on E30's and was vented. It only required a minor
modification to the clamp foot. Now they have taken off the lip on the
short side of the case, again I'm told, to fit some VW tight applications
where the side foot got in the way. That battery used to be about $35, now
I've got to use Central Battery's Interstate clone with funky side-oval
vent for about $75. Anyone have a (cheap) solution for E30 batteries?
Phil Marx BMWCCA #6021
From digest.v4.n611 Fri May 17 07:59:58 1996
From: prreitz_at_amp.com (Paul R. Reitz)
Date: Fri, 17 May 1996 08:53:37 -0400
Subject: <misc> <E30> Exide battery can be made to work.
Phil Marx wrote:
>The real problem is on E30 fitments, as the group 41 battery Sam's sold for
>the E28 used to fit fine on E30's and was vented. It only required a minor
>modification to the clamp foot. Now they have taken off the lip on the
>short side of the case, again I'm told, to fit some VW tight applications
>where the side foot got in the way. That battery used to be about $35, now
>I've got to use Central Battery's Interstate clone with funky side-oval
>vent for about $75. Anyone have a (cheap) solution for E30 batteries?
There is another option for E30s, although it isn't for everyone. It
sounds like the Sam's Club battery Phil was referring to may be similar, so
the following may apply to it as well.
Exide makes an International Series battery (memory wants to identify the
specific model as 2I) that is the right size for an E30, complete with vent
ports, except that it has retaining flanges along the *sides* rather than
on the *ends*. Consequently, the factory clamp won't work.
Since the Exide is available with rather large reserve capacity (A-H) and
high CCA, is available everywhere, and is quite inexpensive ($49 for
high-end 72 month warranty version at K-Mart), I purchased one and
fabricated a clamping mechanism that uses the stock battery tray without
Undoubtedly there are many ways this might be done; I fabricated a clamping
frame by forming 1/8" thick x 1/2" wide cold rolled steel around the
battery. This steel strap clamps a flange (fabricated from bent sheet
metal) on the end opposite the factory clamp bolt hole, then runs along
both sides of the Exide battery, capturing its mounting flanges, and is
then bent to form a V shape which is clamped under a plate bolted into the
stock mounting bolt hole. The battery has a nice, flat, indented region
just a little over 1/2" high just above the mounting flanges into which the
clamping frame fits perfectly. The bent sheet metal flange is captured by
the battery box in just the same way as the original battery.
It took a few hours to fab the clamp, but I thought it worthwhile. It is
very secure, if a bit difficult to fit. The original vent hose just
plugged onto the vent port of the new battery.
[ Help ]
- --Paul Reitz