8 replies to this topic

[FoxenTec]

Hello,

 

I am adding a 12V DC fridge and a small number of DC devices to our ARE DCU Camper shell on our Tacoma.  (Engle Fridge, LED light, USB port for charging cell and a port for a Fantastic Fan to plug into)

 

Inside the Shell: 

 

I have two 12V AGM batteries wired in parallel.  Wired off the positive side is a Blue Sea Battery disconnect switch.  (Between the positive post and the battery disconnect is a 30 amp fuse)  From the Battery disconnect switch, I then feed a Blue Sea Fuse block.  

 

At this time, I ran a #4 wire from the negative side of the batteries (NO shunt installed at this time) directly to the trucks chassis after removing the paint where I bolted the lug to.  

 

The Blue Sea Fuse block negative lug connects to the negative side of the batteries just like the chassis return.  All my 12V DC loads will have two wires (pos & neg) to the device and back to the blue Sea fuse block with an appropriate sized fuse.  At this time, I am not using the trucks alternator to charge the batteries as I will be relying on solar for charging the batteries.  So "no" DC to DC charger or Isolator.

 

I have read that many do not believe the negative side of the batteries needs to have a return to the chassis while others say nothing wrong with this and they would wire as I have done.

 

Based on the experience of others here, is my setup satisfactory?  Am I OK to leave my Chassis return?  Any advice or help would be much appreciated!

 

 

 

Thank you,

Jon

 

[pvstoy]

Looks fine. You have all the grounds return directly the the fuse panel and battery. You do not need a ground to the truck and if it was mine I would remove it.

You might consider running positive and negative from solar to one battery and take positive and negative from the second battery to the fuse panel.

[Beach]

I would remove the unnecessary battery/chassis ground as it serves no purpose. I would add a fuse or breaker between the batt switch and fuse panel, especially if that run is more that a couple ft.  

[Vic Harder]

As said above, you do not need to ground to your truck.  Keeping the grounds simple (back to the battery post) could also avoid ground loops that might lead to electrolysis and corrosion.

[FoxenTec]

Awesome, thank you Beach, Vic and Patrick!  I will remove the return cable to the chassis and will add a fuse between the battery disconnect switch and my fuse block.

 

There is a fuse at the positive battery post that feeds the battery disconnect switch but it sounds like "Beach" mentions also having a fuse between the fuse block and the battery disconnect switch.

 

As always, thank you!

[FoxenTec]

I would remove the unnecessary battery/chassis ground as it serves no purpose. I would add a fuse or breaker between the batt switch and fuse panel, especially if that run is more that a couple ft.  

Hey Beach,

 

Our distance from the fuse panel to the battery disconnect switch is less then 1 foot.  Since the other side of the battery disconnect switch going to the positive of the battery is fused, why is a 2nd fuse needed on the other side of the battery disconnect switch?  

 

Thank you!

Jon

[Vic Harder]

I wouldn't put fuses in short stretches like that.  The fuse is intended to protect the wire and/or equipment you are connecting to.  

[FoxenTec]

That makes sense Vic.  Thank you.

[rando]

I would take this one step further and say you specifically DON'T want to tie into the truck chassis ground here as it can be a safety hazard.   Say the chassis ground wire on your  starter battery were to come disconnected, and you went to start the truck.   All of a sudden the ground path for your starter motor is through your aux battery wiring!    This is the reason that devices that wire directly to the battery and are attached to chassis ground (typically Ham radios or stereos) should have a fuse/breaker on both the positive and negative wires.   This is also a good reason not to ground your camper battery to the camper frame, as it often ends up grounded to the truck.