Battery in trunk

48builder · October 30, 2007, 11:01:23 AM

My battery is mounted in the trunk. I bought a kit from Summit with cables etc. The kit came with a short section of black cable for the ground. My original plan was to run that cable from my battery box to a stud welded through my rear crossmember. From comments I have seen here I'm not sure that is the way to go. I started thinking that if that stud got some mud or corrosion on it, I might lose conductivity.

In the engine bay I have a cable from my common bus to the frame, engine, and body.

What do you guys do? I checked on #2 welding cable and at $2.75 a foot it will cost more to run a cable all the way to the front, but I don't want to have problems down the road.

Walt

GPster · October 30, 2007, 11:53:12 AM

How much do you think trouble on the road might cost? The highest amperage draw in the entire system is your starter. I suggest you run a ground wire to your engine and ground your frame and accessories from it. GPster

Dave · October 30, 2007, 11:59:28 AM

Ive done all mine with speedways cable kit and a tractor supply battery box. I usually use a different ground cable cause the one in the kit never seems to be long enuff. I drill the frame under the car and put my ground there then i also run a short cable from usually the fuel pump bolt to the right frame rail.. Always worked no problems. I also run a dash ground from the dash to one of the transmission bolts.
Dave

PeterR · October 30, 2007, 12:05:23 PM

Quote from: "48builder"My battery is mounted in the trunk. I bought a kit from Summit with cables etc. The kit came with a short section of black cable for the ground. My original plan was to run that cable from my battery box to a stud welded through my rear crossmember. From comments I have seen here I'm not sure that is the way to go. I started thinking that if that stud got some mud or corrosion on it, I might lose conductivity. Walt

Plenty of vehicles with rear batteries (including some as factory installation) run a short earth lead from the negative battery post to the body, then another in the engine bay from body to engine block. However I believe this is not good practice.

The largest currents flow into and out of the engine. The starter draws hundreds of amps during cranking, and a big alternator can punch back up to120A. If the earth lead in the engine bay has high resistance due to corrosion or frayed conductors, then these high currents will find another path and that may be the driveline. Large currents through bearings cause localised pitting leading to premature failure so should be avoided.

My preference (regardless of whether the battery is front or rear mount) is to run the negative lead directly to a hefty stud on the engine or one of the starter mount bolts, then a short lead from the engine to the body. In this arrangement the lead to the body only carries relatively small loads.

1FATGMC · October 30, 2007, 12:08:13 PM

I used one of those kits, but my battery is at the front of the bed and more centrally located. I welded a stud to the frame and run the neg. battery cable to it. Then I have a neg. cable from the starter bottom back to that stud and another neg. cable from the cab to the stud and one from the bed to the stud. Cheap insurance to make sure you have good grounds everywhere. 12 volts doesn't make it very far without a way to get back to the battery, so the grounds are just as important as the hot wires.

c ya,

Sum

phat rat · October 30, 2007, 12:30:40 PM

Battery in my cpe is in the trunk. Ground wire from battery to the frame. Up front have a ground from engine to frame and body to frame

enjenjo · October 30, 2007, 12:41:14 PM

With a rear mount battery, I usually ground it at the rear of the transmission.

Leon · October 30, 2007, 12:51:04 PM

I have a stud welded to the frame and when I put the battery cable on I also used Dielectric grease to keep out any moisture.
Grease

Welder Series · October 30, 2007, 01:42:23 PM

http://www.eddy-current.com/condres.htm

Dave · October 30, 2007, 03:08:05 PM

It really does me no good to ground my body being its glass

I wonder though if it would keep the static electricity down durning painting?
Dave

ps: what ive been doing has worked for 30 years so unless i have a problem im gonna do it my way

48builder · October 30, 2007, 04:10:09 PM

Quote from: "Welder Series"http://www.eddy-current.com/condres.htm

Jeez, silver cable would carry a hefty price tag, but it looks like it would work good!

48builder · October 30, 2007, 04:14:34 PM

Quote from: "GPster"How much do you think trouble on the road might cost? The highest amperage draw in the entire system is your starter. I suggest you run a ground wire to your engine and ground your frame and accessories from it. GPster

Sounds like if I run my ground cable from the battery all the way to my common bus (which is mounted on the inner fender panel), and then run a heavy cable to the block (from the factory this cable was at a motor mount bolt, so I left it there), and then a cable from the block to the body, I will be all set. That's probably what I will do.

Thanks for the tips

Walt

Dave · October 30, 2007, 06:00:43 PM

Quote from: "Welder Series"http://www.eddy-current.com/condres.htm

Thats a very interesting read .. Humm I guess I never needed to know the resaistance on inconel or iridium let alone graphite which happens to be my choice of arrow shafts that made the kill sunday ..

I may just have to print this out just to have.. About the only thing they didnt list was a string outta a dead cats a-s-s--- Im sure Ugly has all this info on his hand held what ever they are?? PaLM pIlOt

Dave

UGLY OLDS · October 30, 2007, 06:23:23 PM

Crazy question , Walt ....Does the battery REALLY have to go in the trunk?? How 'bout under the R/F fender?? LOTS closer to the starter...LOTS easier to run cables to ...LOTS more room in the trunk....

PaLM pIlOt :?: :?: Somebody's having "button trouble " again..... :oops:

phat rat · October 30, 2007, 06:27:07 PM

Quote from: "UGLY OLDS"Crazy question , Walt ....Does the battery REALLY have to go in the trunk?? How 'bout under the R/F fender?? LOTS closer to the starter...LOTS easier to run cables to ...LOTS more room in the trunk....

PaLM pIlOt :?: :?: Somebody's having "button trouble " again..... :oops:

More than just button trouble