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View Full Version : E-34 battery relocation a success.



bones
08-04-2007, 11:47 PM
i know a few people were interested in how this was going to turn out.i moved the battery from the engine compartment to under the rear seat and used the existing 4 guage wire to bring the circuit forward,also used the existing grounding points.new battery cables pos-18 inch' neg 14 inch,850 cca battery with external vent.even with a really long starter duty cycle to initially start a bone dry injection system the cables showed no signs of heat at all and the starter turned over normally.im happy to get the battery out of the temp extreems of the engine compartment even if it's simply for piece of mind. bones

Dr. evil
08-05-2007, 12:21 AM
so all the wring is still in the car even if it was originaly in the front?

genphreak
08-05-2007, 02:22 AM
Great work... it sounds like you already have, but just make sure everything is exactly right (cable size, grounds, etc)- one mistake can end in flames... I'd put an emergency isolator on the battery jic yu have to jump out one day and turn it off- its also easier than having to unbolt the battery post when working on the car!

Morgenster
08-05-2007, 03:49 AM
did putting in the rear seat give any problems?
I just swapped mine with the sea from a car with front bttery and there's an indent on the one I took out especially for the battery casing. The one I put in doesn't completely lock down.

bones
08-05-2007, 09:04 AM
so all the wring is still in the car even if it was originaly in the front?yes,i simply cut the positive battery connector off the engine location,installed appropriate size lugs to install on the fuse box terminals.removed the battery ground cable from its forward location and made the connections under the rear seat.all current still passes through the forward fuse block.att! dont fuse the starter cable in any way,only the accessory circuit.

bones
08-05-2007, 09:08 AM
Great work... it sounds like you already have, but just make sure everything is exactly right (cable size, grounds, etc)- one mistake can end in flames... I'd put an emergency isolator on the battery jic yu have to jump out one day and turn it off- its also easier than having to unbolt the battery post when working on the car!your so right,and i havent done that yet.ill absolutely install some kind of a quick disconnect thats easily accessable. forums are so cool!!!

bones
08-05-2007, 09:10 AM
did putting in the rear seat give any problems?
I just swapped mine with the sea from a car with front bttery and there's an indent on the one I took out especially for the battery casing. The one I put in doesn't completely lock down.youve got to modify the front hold down bracket ,flatten the 90 degree bend and elongate the mounting hole to reach out a bit further and secure the battery.

bmwrp8
08-05-2007, 11:14 AM
your so right,and i havent done that yet.ill absolutely install some kind of a quick disconnect thats easily accessable. forums are so cool!!!

could post a photo of the battery at the rear and at the engine bay?

ktteoh
08-10-2007, 12:47 PM
bones, could you clarify what you meant by "flatten the 90 degree bend and elongate the mounting hole ..." - i don't quite understand.

could you share a picture of your modded hold down bracket?


youve got to modify the front hold down bracket ,flatten the 90 degree bend and elongate the mounting hole to reach out a bit further and secure the battery.

filip00
08-10-2007, 01:13 PM
i think i don't have the wiring under the rear seat...

i would also like to do the conversion to under the seat....please post some pics under the hood now, and under the seat