I know I have some rot in and under my battery tray that I will be repairing soon, and I was thinking this might be a good time to relocate the battery to the trunk. The battery could be placed in a box on the right side of the trunk similar to how it is mounted in the R107. A R107 box and battery might even work. A quick web search did not turn up the type of battery that the 107 uses, but the one in my Mom's 450SL seems as large as the battery in my 240D. Some big 2/0 cable could be used to hook it up. Comments?

You would have to use a different type of battery if you want it to fit in the wells, the group 49 battery is much too big to fit. I would find the biggest battery that can fit in the wells and put two of them in parallel.

2 batts means more $$ in fittings... I've been considering it too though, that battery tray would be a great place to put an aircleaner.

EDIT: What about those drycell batteries? Expensive, yes, but they can be tilted in ways that a normal battery cannot, also might have other benefits due to deep-cycle etc..

I imagine running that much 2ga wire would get expensive, and fast.
If you're going to use dual batteries be sure to hook up an isolator. I ran dual batteries on my old Ranger; It was great to see the look on people's faces when I had jumper cables out and jumped my own truck(classic idiot domelight-left-on killed the main battery)

Simpler=Better Wrote:I imagine running that much 2ga wire would get expensive, and fast.

Not really, 2/0 wire runs about $4/foot. $50 should cover a car.

Quote:If you're going to use dual batteries be sure to hook up an isolator.

There is no need for that. Look at every diesel pickup on the market and you'll find two parallel batteries, semi trucks you'll find 4 or more connected in parallel.

Isolators are for using high power electrics (winches, compressors, hydraulic pumps, lights, etc.) where you can't have them draining the main battery.

I was under the impression that if you didn't have new matching batteries they could draw each other down. The big rigs really don't have any kind of diode/relay between batteries?

well in our s4 we relocated ours with a light weight one, the car understeered less, felt crisp under braking and late apexs. theres no reason why not to. and if you get wire from home depot total cost is under 30 beans!


try it out and tell us how it feels

Simpler=Better Wrote:I was under the impression that if you didn't have new matching batteries they could draw each other down.

Thats why you don't mix-n-match batteries.

Quote:]The big rigs really don't have any kind of diode/relay between batteries?

Just a pair of flat copper plates connecting the poles.

The battery fits in the trunk well, but it will need a stand to clear the lump in the liner that runs in the middle of the well. Anybody know what is under that bump?

FWIW the battery fits perfectly in the trunk well of the W126

I just came across this thread again and thought I'd leave a link of my relocation: http://www.superturbodiesel.com/std/batt...t-328.html

eBay has some killer deals on battery cable, most are under $2.50 per ft for 1/0 and 2/0 cable.

Some models of BMW have the battery mounted in the trunk. the cable I pulled came out of a 525i, and is 11 1/2 ft long and the size of my thumb. also think the 325i also is in the trunk.

battery is mounted in R/R wheel well, cable runs inside the car along the rocker panel, and ends in the eng compartment connected to a block on the firewall.

$3.99 plus tax and enviro fee. about $5

Charlie