How do I connect my battery charger.

[Thos]

I have just received a 60amp battery charger that I want to use to charge my two parallel 12v SOK batteries. The wiring diagram for the charger shows that I must ground the charger to the vehicle frame and then ground one of the two negative terminals on the back of the charger and also ground the negative terminal from one of my two parallel connected 12v batteries.
So I will use 4 ga. cu. wire which is very easy to poke into the two negative lug holes on the charger and I can connect a negative cable from the two parallel batteries using a ring that slides over the battery post.
But I don't know how to properly ground the 4 ga. cable coming from the charger housing lug to the vehicle chassis (other than clamping the cable to the vehicle frame with vice grips). And I don't know how to properly ground the negative outlet at the back of the charger and the cable coming from the negative post on one of the two parallel batteries.
Apparently it is not OK to ground these other two negatives to the vehicle frame is that right?

 

[time2roll]

Generally the battery negative is connected to the frame. The charger negative connected to the battery negative is then grounded. Not sure the total amp load but #4 from the battery to frame is good for at least 100 amps.

In addition the charger may have a chassis ground to have an independent connection to the frame. #8 wire is fine for this chassis ground.

A self drilling-tapping screw into the frame should be sufficient.

 

[Thos]

Generally the battery negative is connected to the frame. The charger negative connected to the battery negative is then grounded. Not sure the total amp load but #4 from the battery to frame is good for at least 100 amps.
Thank-you for replying. So it's OK to connect the battery negative to the frame. Are you saying that I can then run the negative from the Charger to the negative on the battery and then ground a negative cable from the battery?
In addition the charger may have a chassis ground to have an independent connection to the frame. #8 wire is fine for this chassis ground. Yes, the charger has an independent socket for a chassis ground.

A self drilling-tapping screw into the frame should be sufficient. I still don't know how to actually connect these negative cables to the chassis. I can't wrap a 4ga cable around a self-tapping screw. Isn't there some end piece that I need to buy that has socket to clamp the negative cable into and that also has holes in it so it can then be screwed into the chassis?

 

[time2roll]

Normally I would crimp a #4 lug on the #4 wire with a #10 hole and use a #10 screw.

Or a mechanical lug works: https://lugsdirect.com/s2-171-13627-aluminum-hex-screw-2-14awg-lug.htm
Might find this at Home Depot etc.

Yes those connections sound fine. Grounding could get busy with adding additional items. Consider a ground bus to connect all things negative and have a single wire to the frame.
https://www.amazon.com/Blue-Sea-Systems-2304-Common/dp/B0009TUFWA/ref=asc_df_B0009TUFWA

shop around. I don't know the full scope of what might get connected.

 

[Thos]

Normally I would crimp a #4 lug on the #4 wire with a #10 hole and use a #10 screw.

Or a mechanical lug works: https://lugsdirect.com/s2-171-13627-aluminum-hex-screw-2-14awg-lug.htm
Might find this at Home Depot etc.

Yes those connections sound fine. Grounding could get busy with adding additional items. Consider a ground bus to connect all things negative and have a single wire to the frame.
https://www.amazon.com/Blue-Sea-Systems-2304-Common/dp/B0009TUFWA/ref=asc_df_B0009TUFWA

shop around. I don't know the full scope of what might get connected.

Thank-you for the link, I bought a 4 Stud bus bar with a cover from Amazon.

 

[SteveOOO]

hope this helps you. double click the image to enlarge it. Im running a 70 or 80amp charger.

 

[Thos]

Thank-you for the link, I bought a 4 Stud bus bar with a cover from Amazon.

I've got the 4 Stud bus bar from Amazon now and I see that the 4 studs are connected together by a stainless steel bar. But the stainless steel bar is mounted in a larger plastic moulding with a hole for a mounting bolt at each end. I thought that a safe and proper negative ground means that I have to have my grounding cables connected to the frame of the vehicle. With this bus bar that will never happen because the 4 Studs and the bus bar they are in are all sitting in plastic. All I'm doing with this bus bar is joining all my negative cables together.

 

[SteveOOO]

Thos, as you see in the photo above im not grounding to the body of my camper not that you cant, you can and it is a good thing by just running a wire to the frame drill a hole and bolting/Self tap it on 10-12Ga should be fine.(just like the trailer wire is done), in my case all the ground wires and positive wires run to the fuse panel in the camper so grounding it to the frame is not a big deal for me I ran a heavy duty 4G positive and Negative wire to my panel way over kill but I wont have a overload ether.. We use the term bars to connect everything to for better connections & neat neatness. you will need to make sure you have the main ground wire that goes to the fuse panel connected as well as the positive. Connect all the battery & Charger grounds (Black) to the bus bars then do the same for the positives (Red) going to the red bus bar and your done. again add a over load fuse off the battery and shut offs switch. I have added a extra fuse block above the battery box for other items I have or may need down the road.