Invertor practicality question.

[cospilot]

so reading these threads and being an electrical guy i have some thought and would like to get your feedback..

first off, a recent post about installing 200 watts worth of solar panels got me thinking.. i would like to have something to keep my battery topped off while stored in the RV storage lot.
also, to a large degree i question the reality of being able to dry camp with just 12 volts and the water i brought with me but i can think of a few places i may like to try it.
adding solar would be a big help in those situations.

but more to my point i would really like to watch TV and possibly use the microwave. without a generator my only option is to get an inverter because it seems a waste of gas to fire up a stand alone generator and a little noisy to just watch some tv or a movie.

I figure my TV and sound bar probably draw about 200 watts total AC power. if i got an inverter to power these devices with and knowing that with 200 watts at 120 volts = 1.6 amps of draw. by the time you step that up from 12 volts your going toe drawing about 15 amps from the battery

the question is how long will that last if i am running just 1 deep cycle battery? there seems to be a lot of companies making inverters and some are even hefty enough to run A/C or microwave. so there must be a market for them but how practical is it really?

i am skeptical that even 2 batteries in parallel have enough storage to make this a viable solution. even if your recharging during the day with solar.

so where does an inverter come into a practical use? to charge a cell phone?

obviously, a generator makes a lot more practical sense for long term use, but from an efficiency and noise perspective if your trying to avoid disturbing the neighbors. what really makes sense on a regular use basis?
is there a value to having an inverter?

[Festus2]

If you're thinking that you can dry camp for any length of time with just 1 12v deep cycle battery, watch TV and use the microwave from time-to-time, you may be disappointed. In addition to the TV and microwave, there is also the water pump, fridge, sensors/alarms, and perhaps the furnace that you need to include in the equation.

You would require 2 6v deep cycles and about 300w solar panel(s) as a start.
As for the inverter, you would probably need 1750-2000W for a 1500w microwave which doesn't leave you much for anything else.

I understand your desire for quietness in the campground and the urge to go with solar but I think you would be better off with a 2000w "quiet" generator. You can use this to charge your batteries, incorporate an inverter so you can at least watch TV, and the generator can be used for the micro and other items - not all at once mind you. While it might be noisier, it would be considerably cheaper and more practical.

[notanlines]

In theory your idea seems plausible, but in reality it won't fly. A 2000 watt inverter won't actually give you 2000 watts in real time. As a matter of fact, it will "kick off" with any kind of load suddenly demanded that is anywhere near 2000 watts. We have tried numerous inverters (good quality and bad) in the 1000 watt range. One of our refrigerator/freezers draws 800 watts on startup and then rocks back to 200 watts. All of the three 1000 watt inverters immediately kicked off when we tried to use them. Keep us posted on what you do.

[WaltBennett]

I went with 4 ea 100w panels, four Trojan T105 batteries and a 4kw inverter (got it on eBay for much less than the 2.8kw one I was looking for). All the lights are LED and the ref. & water heater are only on propane when dry camping. With decent sun, I can microwave a bag of popcorn, watch a DVD on the 40" with home theater sound, use whatever lights I need and run a table top fan all night. The batteries indicate 80 - 85% charge the next morning and are charged to 100% by mid afternoon. That also includes running the water pump for dishes & a shower.

Installing everything was fairly easy. The really good part was having 50 amp service in the Monty (that's two 30 amp circuits). My converter was not a part of the breaker panel and I just leave it off now. The breaker panel had each of the two 30 amp feeds on alternating breakers, so I could put things I wanted on the feed coming from the inverter and the heavy draw ones on the one requiring shore power. Don't know if your rig would be this easy to do.

[cospilot]

In theory your idea seems plausible, but in reality it won't fly. A 2000 watt inverter won't actually give you 2000 watts in real time. As a matter of fact, it will "kick off" with any kind of load suddenly demanded that is anywhere near 2000 watts. We have tried numerous inverters (good quality and bad) in the 1000 watt range. One of our refrigerator/freezers draws 800 watts on startup and then rocks back to 200 watts. All of the three 1000 watt inverters immediately kicked off when we tried to use them. Keep us posted on what you do.

i wasn't really asking wether or not the inverter can drive these things. my question is more to the point of is it crazy to assume that through the inversion process can you expect a 12 battery to maintain enough storage to run these things (my requirements of a TV and small appliances) for any reasonable length of time?
my guess is the answer is no!
unless you have a pretty large bank of batteries and some way to charge them each day.

[cospilot]

I went with 4 ea 100w panels, four Trojan T105 batteries and a 4kw inverter (got it on eBay for much less than the 2.8kw one I was looking for). All the lights are LED and the ref. & water heater are only on propane when dry camping. With decent sun, I can microwave a bag of popcorn, watch a DVD on the 40" with home theater sound, use whatever lights I need and run a table top fan all night. The batteries indicate 80 - 85% charge the next morning and are charged to 100% by mid afternoon. That also includes running the water pump for dishes & a shower.

Installing everything was fairly easy. The really good part was having 50 amp service in the Monty (that's two 30 amp circuits). My converter was not a part of the breaker panel and I just leave it off now. The breaker panel had each of the two 30 amp feeds on alternating breakers, so I could put things I wanted on the feed coming from the inverter and the heavy draw ones on the one requiring shore power. Don't know if your rig would be this easy to do.


so on a smaller scale, if i gave up the microwave and just used it for the TV and sound system (a sound bar with subwoofer) is it reasonable to expect i can watch 2 - hours of tv still be able to run the heater for the night and be able to recover the next day with 200 watts?

[JRTJH]

Running on one GP 24 or GP 27 Deep Cycle battery, probably not. You could run the TV for that long, but depending on the need for water pump, lighting, refrigerator power, furnace power, you'd be stretching it pretty thin with only one battery. Remember, battery "longevity" depends as much on not discharging to "too deeply" as much as it does on keeping it adequately charged. The "deep cycle" battery is better suited for the type of use you're planning, but it's not an "endless supply of power" when discharged too "deep" on a frequent basis. You'd probably be better served with a couple of quality 6 volt batteries and limiting your TV viewing or possibly four 6 volt batteries. The more "battery power" you have, the "shallower" the discharge will be and that will increase your battery longevity as well as providing "reserve" power during the evenings. Additionally, the amount of "solar replenishment" capability you have will determine the ability of the solar system to "recharge" your battery bank. It's pretty much a matter of having the ability to replace as many "watts" as you take out. If you're "using 600 watts every night" you need to be able to replace 600 watts every day. Whether or not your 200 watt solar system can do that depends on how much you use, how much sunlight you get daily and how efficient your solar control system is at providing power in the fashion your battery bank can accept it.