Originally Posted by viper
Thanks Gary and Stewart for the comments. Here's some addt'l info: my purpose for adding the inverter is to be able to watch TV or listen to a CD without having to run the genset-maybe for a few hours at a time.
To run the TV or stereo/CD player, I'd suggest a small inverter in the 300 to 600W range, depending on the size of the TV and CD player. You can get an idea of the power draw by looking at the nameplate on each device, finding the power draw (usually in watts, but if it is in amps mulitply by 120 to get watts) adding them all up and adding about a 20-30% safety factor. If you can't get to the nameplate you can get a "Kill A Watt
" to measure the power.
A Sine Wave inverter is preferable to a modified sine wave inverter for electronics, I'd recommend Xantrex Prowatt SW's
in 600W or one of the many other brands
of 300W inverters.
With either inverter, I would not recommend running it off a cigarette lighter plug, I'd wire it directly to the battery. I used a 350W inverter on a cigarette lighter (the one by the TV connected to house batteries in our old coach) and it was beeping and turning off because of low voltage. Remember that inverters draw a little more than 10X the current of the 120V devices they are plugged into, so if your TV draws 2A the inverter is drawing about 20A.
The inverters will either come with wiring or give you instructions on what wire size to buy to properly wire the DC side. As far as the AC side is concerned, the easiest way would be to run extension cords, though it may look ugly.
When I moved the 350W inverter so it was directly connected to the battery, I cut the 120V wire going to the TV and added a DPDT relay in an electrical box as a transfer switch so it would automatically switch between inverter and shore power.
You also can run the inverter all the time, though I would not do that if you get the larger 600W inverter you'll be close or over the capacity of your charger, your TV and CD player may run the batteries down when plugged in!
Originally Posted by viper
I was told the converter/charger model they used in those years was a Paralex or (Paralax?) Series 7400 which starts with an initial charge of 14V and after 13 hours goes to the 2nd stage of 13.5V and it stays at that level after that. It is obviously not a multistage converter.
Actually, 13 hr at 14V then changing to 13V is a two step converter, much better than the worst you could get. For your purposes, I'd stick with that converter unless (or until) you get spoiled by not having to use your generator and want to install a bigger inverter/charger (that's what we, did, eventually had a 2500W inverter/charger with extra batteries to support it in that old coach).
BTW, Parallax makes several models of 7400 converters
, and I'd try to verify the model is a "T" series or measure the voltage to insure it really is putting out 14V. Winnie is pretty good at knowing what they put in their coaches, but even the best manufacturers don't remember correctly sometimes!