Can you charge the batteries when the unit is closed with shore power?

[Padgett]

120vac seems to be mainly an American thing. Create two 120vac legs by splitting a 240vac line and using a neutral for return (why 240vac lines have double pole switches). In places that have 220, both sides are hot.

In DC circuits it is really a loop (well AC is also just a much bigger one). Interrupt it anywhere and flow stops.

Some people think that current flow got confused from day one and is really negative to positive. Doesn't really matter except in special cases.

English cars used to be positive ground (chassis return) and it is said that Lucas put the fuses on the ground side so that the components would protect the fuses.

Bottom line is that you can open either side of a battery and it will prevent flow but the only way to eliminate the possibility of ground shorts with shore power is to use an isolation transformer. And 30A 1:1 transformers are not cheap.

What I was getting at was for a battery disconnect, it does not matter which side of the battery you pull (or the center if GC2 in series). One of these is designed for starter current and will handle anything you want to do.

[Bill]

Originally Posted by Burquena

I would like to add a disconnect switch to my battery .... I just need to add a toggle switch ...? This will be in the battery compartment, so I don't need a marine grade waterproof one, but what specs should it have? To avoid draining the battery, I disconnect it between trips (usually 3-4 weeks) and then hook up to shore power for 24 hours before departure to chill the frig and charge up. If it's going to be longer than that, I will pull the battery and put it on a battery tender,at home, but it's hard for me to wrestle it in and out of the TM all the time

Let me tell you how I handled the disconnect switch. Nothing super-duper or magic, but perhaps there is an idea there for you.

The TM's bumper compartment has three parts - the big center one (I store the sewer hose there), and the small side compartments. In the 2720SL, the battery is in the rear, above the left bumper compartment. I lengthened the positive battery wire, and dropped it through a hole I drilled in the floor of the rear compartment near the battery, and down into the left bumper compartment. In that lower compartment, I screwed a weather resistant switch box (Home Depot B33BRS, for example) to the TM frame, added a weather resistant toggle switch cover (Home Depot R5133330, for example) to it, and mounted a 30-amp two-pole toggle switch (Home Depot R62-03032-2WS, for example) in the box. Connect the extended battery wire to the switch terminals, and bring it back up to the battery.

I now have a cutoff switch in the bumper compartment. Why do I want it there? Because you can access the bumper compartment while the TM is closed. The bumper cover will slide off if you release the lower corner latches. Handy.

Note 1: The hole that you drill in the floor will have sharp edges that could cut the insulation on the wires. I used a piece of 1/2" PVC plastic pipe to line the hole.

Note 2: The battery wire should be lengthened on the cold side of the fuse, not the hot (battery) side. The fuse then protects the wires that drop down through the floor.

Note 3: The switch needs to have a 30-amp rating, because the battery wire can carry 30 amps. I used a "two-pole switch", and wired both poles in parallel to increase the capacity.

Note 4: a "two pole switch" is not the same as a "3-way switch". Catalog descriptions are sometimes confusing on this point. A "two pole switch" is actually two separate switches in one housing and operated by the same lever.

My description makes it sound harder than it is.

Bill

[Burquena]

Bill and Padgett - thank you both for the info. I think I will wait until I have the time to do the switch in the bumper so I don't have to open the battery box each time. ( I also like the idea that if I can't remember if I disconnected it I can check with the TM closed.)
Thank you so much for the step by step directions! I really, really appreciate the time so many of you take to answer questions and pass on your experience.

[inghamm]

Originally Posted by Bill

Let me tell you how I handled the disconnect switch. Nothing super-duper or magic, but perhaps there is an idea there for you.

The TM's bumper compartment has three parts - the big center one (I store the sewer hose there), and the small side compartments. In the 2720SL, the battery is in the rear, above the left bumper compartment. I lengthened the positive battery wire, and dropped it through a hole I drilled in the floor of the rear compartment near the battery, and down into the left bumper compartment. In that lower compartment, I screwed a weather resistant switch box (Home Depot B33BRS, for example) to the TM frame, added a weather resistant toggle switch cover (Home Depot R5133330, for example) to it, and mounted a 30-amp two-pole toggle switch (Home Depot R62-03032-2WS, for example) in the box. Connect the extended battery wire to the switch terminals, and bring it back up to the battery.

I now have a cutoff switch in the bumper compartment. Why do I want it there? Because you can access the bumper compartment while the TM is closed. The bumper cover will slide off if you release the lower corner latches. Handy.

Note 1: The hole that you drill in the floor will have sharp edges that could cut the insulation on the wires. I used a piece of 1/2" PVC plastic pipe to line the hole.

Note 2: The battery wire should be lengthened on the cold side of the fuse, not the hot (battery) side. The fuse then protects the wires that drop down through the floor.

Note 3: The switch needs to have a 30-amp rating, because the battery wire can carry 30 amps. I used a "two-pole switch", and wired both poles in parallel to increase the capacity.

Note 4: a "two pole switch" is not the same as a "3-way switch". Catalog descriptions are sometimes confusing on this point. A "two pole switch" is actually two separate switches in one housing and operated by the same lever.

My description makes it sound harder than it is.

Bill

I have all the parts to do this. How did you do Note 3? One wire coming in. How did you do the "Y" to get to both terminals?

[Padgett]

Seperate disconnect for solar ?

That rear compartment is where I put the float charger so need both positive (switch) and negative stub.

BTW what you seemed to be talking about is two single pole double throw switches that are parallelled so just a stub of #10 would work.

Though I would prefer to use something more purpose built like this.

HD (I prefer Lowes) is fine for household items but not so for automotive.

ps and then there is the 100A CB wired with #2 for the 1000W (continuous) 120VAC inverter. And the other 30A CB for the solar to match the one for the coach....

[Brittany Dogs]

I just simply put the 7 pin male end onto the Battery Tender cable. I use this during the camping season when the trailer in in the garage. After I give the TrailManor a shampoo after coming back from an outing, I plug this in to maintain the already charged batteries to keep them charged until the next outing.