RV Batteries


rddog8691

Member
I recently installed a new TV in the front of my MH and want to put in a power inverter so i could run the TV from the inverter intead of running the generator while driving so the kids could watch TV. Would it be better to conect the inverter to the Coach or Chassis battery
 

hertig

Senior Member
Re: RV Batteries

1) Make sure the TV is not visible to the driver. Could be a nasty fine if you get caught driving with a visible TV on (TVs installed in the front at the factory have a switch which cuts power to the TV when the ignition is on).

2) I'd hook it to the Coach battery. This way you reduce the chances of draining the chassis battery to the point where you have problems starting the vehicle. This presumes that the coach battery is charged while driving; if not, perhaps using the coach battery might not be the best choice. There is nothing wrong with hooking to the chassis battery, except for the risk that you might drain it to the point where you can't start the vehicle (if you use it when parked).

Might want to choose your inverter with some care. The cheapest are 'square wave', and most of the rest are 'modified sine wave'. These 'noisy' waveforms can play havoc with some electrical devices (for some reason, they are particularly hard on electric blankets and some 'wall wart' transformers). There are a few 'pure sine wave' inverters which are just like 'real' power, but they can be pricey.
 

hertig

Senior Member
Re: RV Batteries

Well, first read the manual. If it doesn't say, or you want to check, there are ways of putting guages and meters and all kind of technical stufrf, but the 'easiest' way would be to have the batteries 'weak' and take it for a drive. If they are then 'charged' you have your answer, and unlike the manual, even know that it is working.

By the way, there are '3' ways to measure the state of a battery. The first is by sticking a hygrometer into each cell and sucking out a bit of the fluid. This will show you if you have a 'bad' cell, and give you an average view of the batteries' state. Next, you can measure the voltage. This will tell you if it is charging, and might give some indication of a significant problem. Finally, is a load test. This is looking at the voltage while a heavy load is placed on the battery. This really tells you what the battery can do.

In addition, some of the fancier RVs have 'smart' battery monitors which keep track of the batteries usage and provide a computed 'state' for the batteries.
 

ARCHER

Senior Member
Re: RV Batteries

My ole 89 has a battery switch and when it is in "duel" it is charging the coach and house batteries while driving. If not put in duel, it only charges coach battery. "Always start engine when "NOT" in duel".
 

Kirk

Senior Member
Re: RV Batteries

rddog8691
Your chassis alternator does charge the coach battery unless something has failed. All manufacturers have done that for a very long time now. You could be sure by testing but, there is probably no real need to do so. If you want to check, just measure the battery voltage with the engine off, then start the engine and allow it to run for about five minutes and check it again. If the voltage is higher at all, the chassis is charging the battery.
 
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