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DocJim · 05-06-2012, 08:39 AM

We are looking at purchasing a 2007 Newmar MADP but it is an all electric coach (with all new lead acid batteries). We have owned several MH before but they were Propane Electric. We travel to stay with friends who only have 15 amp service at their home.
Is the charger/invertor able to operate the Fridge, Hydrohot (Hotwater only) as well as periodic use of Microwave and stove for a couple of weeks?
I would appreciate input from those of you that have an all electric coach.
Thanks Jim

FlyingDiver · 05-06-2012, 08:45 AM

I'm not familiar with the MADP, but the all-electric KGDBs I've seen don't have the cooktop connected to the inverter, and 15 amps is probably not enough to run it with anything else on at all. The fridge and microwave are on the inverter, so you should be OK with occasional use as long as you keep all other electric use to a minimum so that the batteries can charge in between uses.

You might want to plan on using the generator an hour or so a day when you're cooking to top up the batteries.

joe

Gary RVRoamer · 05-06-2012, 02:16 PM

Well, 15 amps is just 15 amps and you can only run so much at one time. The microwave in my coach (A GE Advantium) uses almost 15 amps when it runs and 20A when in convection oven mode. My Norcold 1200 fridge uses a bit over 5 amps when the cooling cycle is engaged and my inverter/charger is pretty much drawing 1-2 amps all the time.

Your electric fridge is probably more efficient than my Norcold 1200, but still figure it draws 3-4 amps when running. Since you can't predict when it will cycle on/off, you have to assume that level of amp usage at all times.

Your Hydrohot system can run in diesel or electric mode. The electric heater in the Hydrohot is 1650 watts, which equates to about 14 amps, so put it in diesel mode and leave it that way for hot water. Do not attempt to use the electric heating mode with 15 amp shore power.

Your inverter won't invert as long as the coach is connected to the 15A shore power, but when you trip the breaker on the outlet you are plugged to, the inverter will come on instantly (if left in standby mode).

You can forget about air conditioning too.

If its an all electric coach, you probably have an electric cook top. You didn't mention the type, but even if it is a 120v induction type, it still probably uses a lot of amps, since most thing that heat are large power draws. I would suspect you cannot use the stove.

What you can do is run the generator when you need to microwave or cook and then shut it off and go back to shore power for background power needs. I doubt if the stovetop is wired to the inverter. Or the Hydrohot either.

DocJim · 05-06-2012, 03:16 PM

Thanks, I guess what I needed to know is that when the unit is plugged into shore power 15 - 30 or 50 amp it is charging the batteries and providing power to the rest of the coach but not inverting from the batteries.
As soon as it is unplugged then the invertor starts to work.

I looked at another all electric coach that had a seperate charger on the house batteries so it could plug into 15 amp shore power to only charge the batteries while the coach remained unplugged and inverted off the batteries to run what was nesessary in the coach.

Is that wise?

Jim

Cat320 · 05-06-2012, 04:07 PM

How many house batteries do you have? The new ACs have eight 6 volt batteries and two inverters, one 2800w and one 2000w.

Gary RVRoamer · 05-07-2012, 03:04 PM

Yes, you can run a charger on the batteries and use the inverter to provide 120v power. I've done that once myself. But you will still have things that are not powered by the inverter, e.g. the Hydrohot.

Some all electric coaches have two independent house battery banks, typically one for the fridge and one for everything else. Each would have a separate inverter/charger.