Topic: Relocating battery: Ground?

[Laminar]

I'm considering relocating my battery to the void in my cafe seat. I know that the ground line should typically be as short as possible. Do I just make a longer ground line to the stock grounding location or should I find a new place on the frame to ground the battery to? 

[mystic_1]

or should I find a new place on the frame to ground the battery to? 

Yes.

mystic_1

[Laminar]

Easy enough. The ground appears to be about 8 gauge. Does that sound right?

[TwoTired]

are you still using the electric starter motor?

[Laminar]

Yes. Will that be an issue?

[Inigo Montoya]

I dont know if I would worry so much about keeping the wire so short. now granted these are not cars but check out your cars ground.  Many I have seen are a foot or more and have higher demands. If you are moving to the seat hump, the wire would need to be maybe a foot? Maybe less if you are using an agm battery which can mount in any position. As long as the ground is good, would it really make a difference?

[TwoTired]

Yes. Will that be an issue?

Needs to be considered.  See this chart: http://www.powerstream.com/Wire_Size.htm

The starter motor draw about 120 amps.  It is considered intermittent in this case, so the off times should allow for wire cooling.  8 Ga. is good for about 73 amps continuous.  I think I would prefer 6 Ga., if kept very short you should be ok.

Also consider the ground current for the starter motor must travel through the engine case where it connects to the frame  Pay attention to the path it will take through the frame to wherever your new battery to frame connection exists.

Try to eyeball the current path along the frame.  And make note of any accessory components that make a frame connection along that path.  For certain you don't want the harness ground to be in that path, or components might share some of the starter current loads.

Current will take the shortest, most direct path...for most of the current.  But, that doesn't mean some current won't take other paths as well if they are available.  Drawing high currents through lighting elements will shortent their life considerably.
Also, be certain the new frame ground connection has at least as much contact area as the cross section area of the wire you've chosen.  More area is even better.