[VanGuy]

I have a PM3-45 charger, and I'm using it to connect to "shore power" - My question is: Should I connect the charger directly to my auxiliary/accessory onboard battery, or to a positive fuse bus which I use to connect to all other accessories? (Solar panel, separate inverter, etc) or does it not matter? (IE will the shore power from the PowerMAx charger just naturally be pulled to the battery in either case, whether connected to the terminals or to the positive bus).

Also, do I need to do anything with the small "ground terminal" even if I already have a negative/ground connection from the charger to the van's chasis/body ground?

Thank you!

 

[KeepMeMoving]

I would think any point with little resistance would not be a problem for connecting the charger. On my install I connected the charger to the + terminal of my fuse block which connects to my battery. Wire is 2GA so the resistance is small.

My charger, fuse block and battery are grounded to the same point with 2GA.

 

[GaryBIS]

Hi,
Electrically, I don't think it makes any difference which of the two ways you hook it up.

If you take the approach of hooking all the stuff to the plus terminal of the house battery, the connection gets kind of crowded and having the bus to make these connections to is a bit cleaner and easier. I did not use a bus on mine, but if I were doing it again, I probably would. You might want one for the negative connections to the house battery as well.

BlueSea makes some busbars for this.

It seems like the line from the charger to the house battery should be sized for the 45 amps (eg #8 or #6 ) and fused for the same -- the install manual should say something about this.

If you are using the chassis as the as the return path for the charger, I would think about this. I think its better to run a full size negative wire from the charger to the negative terminal on the house battery (or the negative bus if you use one). Relying on chassis for the return path can lead to problems over time due to corrosion, and they tend to be hard to find.

If the charger has a ground terminal, then I'd say it should be hooked to a good ground -- but, the install manual should have something to say about this? Generally grounds like this are there for safety and best used.

Gary

 

[KeepMeMoving]

.... Relying on chassis for the return path can lead to problems over time due to corrosion, and they tend to be hard to find.

Gary

I have spent way too much time through the years chasing chassis ground problems. I have a single grounding point and ran a ground wire to that one point from each major item. All smaller loads I ran a pair of wires from the fuse block.

 

[RDinNHandAZ]

Finding grounding problems is frustrating but not impossible. There is a characteristic high resistance connection if corrosion has occurred. Good grounds read 0 ohms (ZERO) but many circuits will have a small resistance due to the intervening wire- lets say a few ohms. If the path to ground reads above about 5 ohms the ground is bad. We have a lot of circuits in our house battery system but not so many one cannot find that bad ground in a few minutes. I have both chassis and Buss grounded circuits and feel good about both. If it is an intermittent poor connection then set the meter to beep and start wiggling wires, yes there is a real test called the wiggle test! I have stopped trying to trace wiring in the van (due to my motorcycle experience) relying on the CAN-BUS to find them. Light bulb resistance and simple stuff perhaps but even those will show up on the van's computer.