dual battery earth

[ledgend80]

just after peoples opinion on mounting the earth wire from my dual battery setup to the head of the engine. was going to mount it to the bolt on the head that is holding the accelarator cable.

engine is a 1hdt

[-Scott-]

I can't imagine any circumstance under which I would think that's a good idea.

Why would you choose to do that?

[VooDoo]

Decent earths are always a good thing. There is no problem using that bolt but direct to the block is usually better. You can get premade leads at autobarn. I always add a decent earth to the engine (the ECU runs better with a good earth)

[ledgend80]

I can't imagine any circumstance under which I would think that's a good idea.

Why would you choose to do that?

why would you not earth there? . and where would you earth to?

[brissle]

i would put it on the body near the battery, should already be a thread in the inner guard, just get a bolt to suit.

[mgundle]

we are all forgetting what charges the battery?
the alt
which is bolted to the engine, my advice to get maximum current into you battery choose your earth to the block and run a separate earth to the body and run a corresponding charge supply to you battery

[DamTriton]

I can't imagine any circumstance under which I would think that's a good idea.

Why would you choose to do that?

why would you not earth there? . and where would you earth to?

I'll have a go...

Just suppose you re drawing heaps of current from your battery with a dodgy body earth (happens a lot!!). Extra current through the accelerator bracket heats up accelerator bracket enough to melt the plastic covering the accelerator cable. Molten plastic hits accelerator center wire and cools, or outer cable sheath becomes dislodged in holder.......

Wire of decent size and length for the application is dirt cheap. Don't skimp. Engine block bolt would be fine, there is already a bolt hole about 4" to the right on that picture, use that. More importantly for a second battery would be a decent chassis/body earth as your fridges etc aren't connected to the engine.

[PJ.zook]

Use youre chassis as the main earth centre for all youre major devices. Earth both youre batteries to the chassis, earth youre body to youre chassis, earth youre block to the chassis.

[brissle]

we are all forgetting what charges the battery?
the alt
which is bolted to the engine, my advice to get maximum current into you battery choose your earth to the block and run a separate earth to the body and run a corresponding charge supply to you battery

the wire on the alternator is probably only 6mm anyway so this doesnt really mean a thing, wont the charge to the second battery come from the start battery?

I'll have a go...

Just suppose you re drawing heaps of current from your battery with a dodgy body earth (happens a lot!!). Extra current through the accelerator bracket heats up accelerator bracket enough to melt the plastic covering the accelerator cable. Molten plastic hits accelerator center wire and cools, or outer cable sheath becomes dislodged in holder.......

Wire of decent size and length for the application is dirt cheap. Don't skimp. Engine block bolt would be fine, there is already a bolt hole about 4" to the right on that picture, use that. More importantly for a second battery would be a decent chassis/body earth as your fridges etc aren't connected to the engine.

_________________



I thought he was fitting dual batteries, what are you on about? fridges etc will be connected to the second battery right? so what is all this accelerator crap?. If you dont run an earth for your fridge back to the battery, you will bolt it to the body, so it will be better to bolt the SECOND battery earth to the body.

Dont mean to sound rude but you blokes dont really sound like you know what your talking about

[chimpboy]

so what is all this accelerator crap?

It was an explanation of one reason not to use the bolt from the acc cable bracket as an earthing point.

Which, imho, is good advice.

I don't mean to sound rude but I think your reading comprehension skills need some work.

[-Scott-]

we are all forgetting what charges the battery?
the alt
which is bolted to the engine, my advice to get maximum current into you battery choose your earth to the block and run a separate earth to the body and run a corresponding charge supply to you battery

That's a good point. I was thinking in terms of paralleling the second battery as close as possible (electrically) to the primary battery. I'm used to seeing battery negative cable goes to body first, then off towards engine. I guess I'm hung up on battery negative straight to body / chassis.

From a charging point of view, shortest connection to the block makes sense.

From a discharging point of view, shortest return path (from the load) will be (I expect) direct to body.

I think mgundle is right. Two wires is a good solution.

[brissle]

so what is all this accelerator crap?

It was an explanation of one reason not to use the bolt from the acc cable bracket as an earthing point.

Which, imho, is good advice.

I don't mean to sound rude but I think your reading comprehension skills need some work.

i read it fine, , yes it is good advise not to earth at that point agreed, but imho i think this explanation is still crap.
Anyway prehaps the next question is, dual battery isolator, or parallel batteries, maybe some confusion over this but then again I can't read very well....lol.. all in fun

[dave 2000]

In the UK it is pretty much standard to run an earth lead either, from battery to body and continue on (one cable) to the starter motor securing bolt or, battery to body and then a separate cable, body to starter or gearbox bolt. Of course if you have a separate chassis/body combo then remember that has to be earthed together as well.

regards

Dave

[krusty182]

Ideally, I would earth each battery to the chassis and the engine block if it is practicable, and the main battery should also earth the body.
If the second battery is mounted away from the engine, I would just earth to the chassis because it runs the length of the vehicle, saves using extra cable unnecessarily and has plenty of current carrying capacity.

[dave 2000]

Just remember that if you have a:.......chassis.......and a .....body.....and an engine......they all need to be connected to earth.

Less complicated nowadays though now that many off road vehicles are becoming a simple unitary construction body.

regards

Dave