Suitcase solar grounding question

[stevea]

I am building an all Renogy setup. Portable 200 watt suitcase panel with integrated controller connected to two 12v agm batteries. Off the batteries I’ll have a cigarette socket adapter and an inverter.

I am using this to power a whynter fridge 24/7, laptop, cellphone, lights and maybe a radio. 


I will have the batteries sitting in my runaway camper. Do I need to ground them? If so, how do I do this?

The batteries are inside on a shelf approx 2 feet off the ground.

 

[Matlock]

Can't ground something on rubber tires.
DC current has a neutral and a positive, no ground.

If your camper is all metal you can run one neutral wire from battery to camper frame and then the neutral wire from ciggy sockets can have one wire to the frame and the other positive wire back to battery. In such a small camper with short wire runs I'd just run a positive and a negative wire to each ciggy plug, don't forget to properly fuse each positive wire with the correct size fuse, really close to the battery or pick-up a "blue sea's" fused panel box for solid connections.

And constant plugging and unplugging into a ciggy outlet sooner rather than later means failure of ciggy plug. Also the whynter power consumption wires should be larger than the wires you install for cell charging. Maybe true for laptop too. Watch for warm wires when in use, warm can get to hot then melted so easier to upsize wires from the get-go.

just my ol 2¢

 

[Trebor English]

There's no need until you connect to the alternator for additional charging. The alternator negative side contact is the bolts that attach it to the engine, grounded to the vehicle chassis.

 

[highdesertranger]

I would bond the negative side of the batteries to the chassis. just cuz.

the fridge should be wired on it's own dedicated circuit.

also besides the ciggy plug I would at least do a couple USB's and an Anderson or two.

highdesertranger

 

[Weight]

I'm with hdr. Connect the negative to the chassis. Run a dedicated negative from the fridge along with the positive. However the battery does not have to connect to the chassis as long as all the negatives come back to the battery with wires.
How I do circuits. Battery negative and positive to fuse block. Battery negative to chassis. The appliances and outlet plugs go to the Blue Sea fuse block with positive and negative connections. Small draw items such as led lights can have the negatives to the chassis. Fewer wires to route.