Artum Snowbird
Campbell River, B.C., Canada
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I am seriously considering the addition of an inverter permanently wired in with a DPDT switch to separate the two systems. For the most part, it would be for watching TV for a few hours... Maybe 200 watts load. Other great uses if I can get into the microwave/convection oven and connect to just the exhaust fan. This fan sucks fumes off of the stove top. And most important, a few minute burst to power the coffee grinder, and small chargers for short times.
What's the reasonable amperage limit I can take from two Group 27 batteries for watching TV purposes and still leave enough in them to pull in the slide or run the water pump?
I am looking at a draw load of around 25 amps from the DVD and TV. and keeping this load going for a few hours... then getting it fully recharged driving the next day for a couple hundred miles.
Any reason to put in an inverter more than 600 watts?
thanks for your thoughts, Mike
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MrSeven21
Cape Cod MA
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You said 25amps from a tv and dvd? I have a 1000 watt inverter and when we use the tv and dvd,I think it uses something like 33 watts total. Now when we hook up the coffee maker it go's up to 850watts. If all you want to run is small electronics you should be fine with a 600 watt inverter for a week or more without a recharge.
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skipnchar
Google Kansas USA
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I use a 750 watt for pretty much the same purposes but add a satellite receiver to the mix when watching tv. 750 is WAY more than is needed for that purpose.
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Artum Snowbird
Campbell River, B.C., Canada
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A week or more without recharging?? How can that be? If I am pulling 30 Amps per hour... Two batteries won't last very long doing that will they?
12 volt Group 27 Deep Cells...
But how much can one expect to be able to take out in an hour before it becomes over discharging at too high a rate. I am thinking 360 watts out is 30 amps, divided by two is 15 amps per battery. What will they take? 30? 45?
thanks, Mike
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smkettner
Southern California
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Should not be a problem. If the slide does not come in you just connect to the running vehicle for more power. Water pump takes very little power.
Now if it is close to freezing and you need to also run the furnace all night you may run out of juice.
I am inclined to recomend an automatic transfer switch instead of the DPDT.
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2oldman
Indio CA
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Artum Snowbird wrote:If I am pulling 30 Amps per hour... Two batteries won't last very long doing that will they? What will they take? No, not at 30a, but a TV/DVD doesn't take that much. You may already know batteries' voltage will drop more the more load you put on them, like a microwave. Your two batteries wouldn't hold up to a 30a load for more than about an hour, in my estimation.
Have you consider the easiest, whole-house approach of just plugging your coach into the inverter? You spoke of getting into the exhaust fan and using a dpdt switch. Those two chores may be a bit harder than you think. Of course it depends on how much inverter use you expect to do.
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Artum Snowbird
Campbell River, B.C., Canada
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OK... I think that the Sony Wega pulls 265 watts.. almost 22 amps at 12 volts.
Considering the other loads that are running in a boondocking motorhome, fridge, sensors, light or two, water pump on occasion, coffee grinder(165 watts), furnace motor
that becomes my question. Is the idea of putting the Sony onto an inverter just asking for trouble for a few hours of TV watching in an evening.
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tafische
Memphis
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You are just about at the "Reserve Capacity" pull for a battery. That is defined as the number of minutes you can pull 25 amps at 80o until it reaches 10.5 volts. A group 27 is what? about 150-175 minute reserve capacity per battery? So at best you could watch 4-5 hours of TV if you ran nothing else. I also dont like going that far down on my batteries since it lessens the life. Your inverter may even kick off before that so you wont get that low.
If it were me, I would get a small quiet generator if you are wanting that much power or buy yourself a set of dedicated 6 volts for your TV so you dont risk loosing your other functions.
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Artum Snowbird
Campbell River, B.C., Canada
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Thanks Tafische, that's about the way I see things too. It's too bad that Class C makers don't realize the need for a super quiet 500 watt miniature generator tucked in somewhere. It wouldn't even have to be electric start, but if it had an on/off switch inside, and a pull cord to get it going outside, it would just be so useful.
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smkettner
Southern California
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A Honda/Yamaha 1000 and 40/45 amp converter is about as close as you will get.
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