Thread: Faulty earthing causes problems.

Hi,
I recently fitted a Traxide SC80 battery isolator and was having problems with the second battery not reaching full charge while driving for a few hours.
After discussing the problem with Tim (Drivesafe) I had a list of checks to run, and more consultation with Tim, found a Voltage difference between the two battery negative terminals.
Bingo!
Move the 6 B&S cable from a body earth point (seat rail bolt) and hold it on the Battery negative terminal and Zero Voltage difference.
Thanks Tim for your time and patience in sorting that out for me.

I have the SC80 on the rear bulkhead of the battery compartment, mounted on a shaped piece of ply wood.



Some accessory sockets in the cab are now run from the back of the SC80 so they can no longer flatten the vehicle battery. If the Innovan is on the tray and plugged in, these accessories run from the second battery.

I could not make a connection to the vehicle battery negative terminal easily, (thus the reason for using a body earth point) so I ran a 6 B&S cable from the transfer case bolt that has the vehicle earth attached, back up to the body earth point I was using.

With the battery back in, there is just enough room for the SC80 in behind,



but I will move the unit more to the passenger's side in behind the battery to prevent it contacting the wheel changing tools stored in the battery compartment.

A quick trip down to Kingston and Justin provided and fitted the correct nut to fit the transfer case earth mounting point.
It would have been a knuckle bleeding job to do without the hoist and correct tools - many thanks for doing that, it was much appreciated.

With the second battery now earthed solidly to the same point, both batteries are the same voltage, and with 6 B&S cables there is no measurable voltage difference when the SC80 is active.

cheers

Originally Posted by DEFENDERZOOK

why didnt you just earth the second battery direct to the first battery......?

wouldnt that be easier......?
thats what ive done in mine.......i just joined the two earth terminals together....
as the two batteries are side by side......it was the quickest and easiest way i found.....
and also.....couldnt get a better earth than that.......

Dave isn't running a second battery inside the compartment D'zook. The wiring was already run out of the battery box and as the transfer case main earth was right 'there', it is just perfect. Now measured voltages are identical.

JC