$.80 solar panels

EldIr wrote:

We have cfl's and an lcd tv to run off the inverter, but we're still programmed to run the inverter as little as possible to save the batteries. That's why the car stereo and running the cell phone booster off 12v. I'll update the inverter draw as soon as I get back up there.

Car stereo is a great idea as home entertainment systems generally draw a lot of power. Although searching for the right components will find really low draw electronics. I found a Bluray player, while I was searching for something the 12V guys can use, that only draws 10W per it's specs but it's 120V only (not good for the 12v guys...found them something that draws ~14W).

BFL13 wrote:

EldIr wrote:

BFL13 wrote:
No way is that 3 amps with a 300w inverter. Something else must be going on there.

Eg using the 1000w inverter and a 120v CFL lamp I get a 2 amp draw showing on the Trimetric, vs a 3 amp draw with no inverter and one 12v two bulb lamp. The CFL lights up the whole place in comparison with the 12v lamp. ( I don't have the newer, better LEDs for the 12v lamps)

I won't be back to the cabin until the week after next due to work. I'll recheck the inverter manual and test the draw with my Fluke but I'd swear the manual said the inverter draws about 30w. It does have a cooling fan that runs any time it's on regardless of load and I know some of those aren't very efficient. It is quite old from before pure-sine inverters became all the rage. (back then, even the cheap modified-sine were still expensive not like the 30 dollar ones at the auto parts stores now.)

Back in the 90s :) they had 12v TVs etc so you didn't need an inverter and RVers got the idea that it was easier on the batteries to use 12v directly instead of wall warts on 120.

Now that is all "so yesterday" with switch mode mofset inverters and LED Tvs, CFL or LED lights. etc etc. Today you can do it all via inverter and get better TVs and other things to run off 120v and forget the whole 12v idea unless forced to.

New cabin in 2013? Do a 20yr upgrade from the old '93 cabin :)

The old cabin is closer to '53 than '93:B

We have cfl's and an lcd tv to run off the inverter, but we're still programmed to run the inverter as little as possible to save the batteries. That's why the car stereo and running the cell phone booster off 12v. I'll update the inverter draw as soon as I get back up there.

EldIr wrote:

BFL13 wrote:
No way is that 3 amps with a 300w inverter. Something else must be going on there.

Eg using the 1000w inverter and a 120v CFL lamp I get a 2 amp draw showing on the Trimetric, vs a 3 amp draw with no inverter and one 12v two bulb lamp. The CFL lights up the whole place in comparison with the 12v lamp. ( I don't have the newer, better LEDs for the 12v lamps)

I won't be back to the cabin until the week after next due to work. I'll recheck the inverter manual and test the draw with my Fluke but I'd swear the manual said the inverter draws about 30w. It does have a cooling fan that runs any time it's on regardless of load and I know some of those aren't very efficient. It is quite old from before pure-sine inverters became all the rage. (back then, even the cheap modified-sine were still expensive not like the 30 dollar ones at the auto parts stores now.)

Back in the 90s :) they had 12v TVs etc so you didn't need an inverter and RVers got the idea that it was easier on the batteries to use 12v directly instead of wall warts on 120.

Now that is all "so yesterday" with switch mode mofset inverters and LED Tvs, CFL or LED lights. etc etc. Today you can do it all via inverter and get better TVs and other things to run off 120v and forget the whole 12v idea unless forced to.

New cabin in 2013? Do a 20yr upgrade from the old '93 cabin :)

30W standby is WAY too much. Mine draws .26A and it's a 300W PSW.

My Xantrex digital 400-watt inverter uses 0.25 Amp on standby... thats 3 watts. I can't find another one that uses less, or I'd buy it. smile

BFL13 wrote:
No way is that 3 amps with a 300w inverter. Something else must be going on there.

Eg using the 1000w inverter and a 120v CFL lamp I get a 2 amp draw showing on the Trimetric, vs a 3 amp draw with no inverter and one 12v two bulb lamp. The CFL lights up the whole place in comparison with the 12v lamp. ( I don't have the newer, better LEDs for the 12v lamps)

I won't be back to the cabin until the week after next due to work. I'll recheck the inverter manual and test the draw with my Fluke but I'd swear the manual said the inverter draws about 30w. It does have a cooling fan that runs any time it's on regardless of load and I know some of those aren't very efficient. It is quite old from before pure-sine inverters became all the rage. (back then, even the cheap modified-sine were still expensive not like the 30 dollar ones at the auto parts stores now.)

Newer pure sine inverters up to 1000w output use around .5 amps or less when not powering a load. Nearly all are better than 94% efficient.

You'll have to make the decision whether having all 12V appliances is better than a mix of 12V and 120V items but I'm guessing that you are going to have some of each. That means an inverter is going to be in use, anyway. FWIW, I think the difference in standby load between a Samlex 600W and a Xantrex 1000W is less than 250 MA, maybe less.

No way is that 3 amps with a 300w inverter. Something else must be going on there.

Eg using the 1000w inverter and a 120v CFL lamp I get a 2 amp draw showing on the Trimetric, vs a 3 amp draw with no inverter and one 12v two bulb lamp. The CFL lights up the whole place in comparison with the 12v lamp. ( I don't have the newer, better LEDs for the 12v lamps)

I think a couple of you are misunderstanding my efficiency question. It's not about comparing 12v to 120v loads. It's about the inefficiency of the inverter itself. The inverter uses some of the power coming from the batteries just to run the inverter. If you're running 12v loads, you're not wasting the power the inverter itself uses. I think our 300w pure sine inverter draws about 3amps all by itself independent of what it's outputting.

Also starting to look at hydro as an option as we're right on a river. Need to do more math as the initial purchase is higher than solar, but running 24/7 the power over time may end up costing less.

We had a thread here not long ago where were looking at possible "remote" power supplies for an RV where the RV had no battery in it. All you need is to plug the 120v shore cord into an inverter in the power supply.

The RV converter makes any 12v needed, but of course it costs extra amps (about 6a being a typical amount, so in an hour that's an extra 6 AH to get from the solar later on.

A cabin does not need any 12v stuff, just 120v, so you could park a 48v golf car (or your truck with batteries in the bed) outside with a 48v inverter strapped to those batteries and put solar on the roof of the golf car.

If the cabin is in the shade, move the golf car out into the sun--it doesn't matter so much how long your 120v line is to the cabin.

We park our RV for long periods in the one place and use it as a sort of cabin, so I keep looking at this, but can't escape the RV's 12v stuff totally (so far! :) ) A real cabin saves you from that.

Anyway it is another approach to the problem to give a thought to.