Hi All
Can any one advise me on what size fuse/ circuit barker I should use when relocating the battery into the cabin on my RX8 race car?

 

200a

 

200A is probably good, circuit breaker is nice because you can turn it off if the car needs to sit for a while.

i looked at a bunch of OE cars with batteries in the rear, and actually none of them have a fuse or circuit breaker that is additional.

the 1990-2005 Miata's, just run the battery cables in a sheath thru the PPF, no fuse nothing.

the MGB was similar, except i think the battery cable is just on the floor under the carpet, i think, nothing fancy here.

the E30 BMW is the funniest, they leave the battery cables from the normal front battery location, put the battery in the trunk, route the cables thru the interior, and it ends in a male battery terminal, that literally just plugs into the normal battery wiring. does this seem like a lame afterthought? yes. does it make it really easy to do? yes.

so to recap, the OEM's put the battery in the trunk without a fuse or circuit breaker, however a circuit breaker is kind of handy, and not a bad idea. furthermore if you follow BMW's lead you can run the battery in the back and make no changes to the original Rx8 harness.

 

thanks.
my dad's rx7 has no fuse but thought it couldn't hurt to add one in my car





Posted from Rx8club.com App for Android

 

the main reason of the fuse is to prevent a violent amount of current running through the cabin should something go wrong with your electrical system. If you are using cheap battery cables it is a recipe for disaster when the current fries the cables and sets everything in its path in flames.