Battery Isolator

[PcHistorian]

well, making margarita's all day, every hour on the hour... no breaks for chow, would use a lot. This chart would show why so many people are switching to LED lights, fraction of incandescent, by amps and wattage, and saves a great deal if on battery only. Compare a blender with a light bulb. Blender takes more wattage. Go by wattage. An LED light is about (2v DC at 0.01 amps, so 0.02 watts. A hundred of them would be 2.0 watts.(at 50 of them, you's light up the forest!))

I like that "x 11 to get DC amps from AC amps, 120v to 12v. (wattage stays constant, except for inverter/charger in-efficiencies.)

One thing to note here while I am tripping over the subject in the back of my mind. Some people have been considering using an inverter in the tow vehicle, and then a charger in the trailer, and running the 120v cord to the trailer from the tow vehicle to charge while driving... Why? Because the loss of energy transfer becomes smaller for distance, same reason as why the electric company transfers power in AC instead of DC, at high voltages. 2 volts from 120 is a smaller loss that 2 volts from the alternator's 15. Smaller power loss for distance. (realize though, this multiplies your expense for inverters, as you'd have one in your trailer, too, but at least you could use the same charger 120v to deep cycle, from tow-inverter or shore power.)

Lastly if you haven't bought batteries yet, some people here say buy two 6v golf cart batteries for in series, instead of 12v deep cycles, they work better/last longer Life of battery (same charge depth).
(I have yet to experiment with that, just saying.)

[VermonTear]

Thanks guys. I'll recalc.

[VermonTear]

Lastly if you haven't bought batteries yet, some people here say buy two 6v golf cart batteries for in series, instead of 12v deep cycles, they work better/last longer Life of battery (same charge depth).
(I have yet to experiment with that, just saying.)

Well, I have already have my battery. Besides, space is of the essence in my build so I really, really only have room room room room for one battery if I want anything else in my galley. Good info though!

best...

ken

[VermonTear]

Next question...

Should my ground wire --- from the battery back to the RV Chassis -- be sized the same as the load wire from the vehicle battery to the Tear battery? ie if I go with #8 load wire should I stick with #8 ground?

ken

[PcHistorian]

Unquestionably YES. (pressure (amperage) is constant through out the loop. You may sub divide it amongst the far end, but coming and going to the battery, either wire carries the same amperage.

think of it like a water flow with the battery as the pump. the same amount of water comes into the pump as goes out. at the far end you can sub-divide the flow into lots of little (or big) pipes, but in the end, it all comes back to the same flow going through the pump.

(all those devices at the far end have little water wheels to take energy from the flow past them, but the flow stays in the pipes.) big chores need bigger pipes, smaller chores get smaller pipes, but at the pump is the biggest pipes. pipes too small, everybody gets too little flow. might blow the pipe out (burn out the wire) if the pipe is way too small. pipes too big, everybody gets their fair share of the what the pump puts out. (too big is ok with the pump or device, just allows for a smoother flow.)

(boy I said that rather well. I should take notes on myself. the explanation came out well that time. :-)

[VermonTear]

Unquestionably YES.

Thanks, PC... That answered my question. Good explanation as well!