Inverter

[HappyCamperCanada]

I want to run a set of 6 patio lights (40W bulbs), an LED lit palm tree, and charge 2 cell phones off an inverter connected to a 2 90 amp-hour battery bank(180 amp-hour total). What size inverter should I get? 300W or 500W. Or should I be looking at 1000W? Will those items drain my batteries much? Thanks.

[Jay2504]

I would at least get the 500 watt Inverter. Look at the specs for stand by current. That’s how much it takes for the Inverter to be turned on with no load. You might find out that a 1000 watt unit will use less current. Jay

[HappyCamperCanada]

So I bought a 500W inverter today. Gonna try it out next week camping and see how it performs. It connects directly to my two 80 amp-hour deep cycle batteries (wired in parallel) via alligator clamps. I'm going to use it to power my 30w LED palm tree (for a couple of hours per night), six 8w LED patio lights (48w, also for a couple hours per night), and charge 2 cell phones (I read somewhere that a cell phone charging is approx 10w). Anyone have a formula that would calculate how much battery all of that would consume?

[JLeising]

Power in watts is volts X amps. Using you numbers, and assuming the cell phones are also charged for a couple of hours, 30 watts plus 48 watts plus 20 watts (2 cell phones) is 98 watts. At 12 volts, 8.2 amps. Round up for inverter efficiency loss, about 9 amps. Two hours should use a little less than 20 amp-hours.

Inverters have a draw even when supplying no output - best to turn it off when not using the output. Also, I use 12 volt chargers for our cell phones- avoid the inverter losses.

[HappyCamperCanada]

Thanks. What's a 12 volt charger for cell phones?

[flyerdp]

Originally Posted by HappyCamperCanada

Thanks. What's a 12 volt charger for cell phones?

Hes talking about car chargers that use power ports/cigarette lighters to run off the 12V in the trailer.

I was going to suggest it but wasnt sure how comfortable you would be running 12V wires and adding power ports.

[HappyCamperCanada]

Sounds like something I could do if I knew what exactly I'd need. Something like these?

[flyerdp]

Originally Posted by HappyCamperCanada

Sounds like something I could do if I knew what exactly I'd need. Something like these?

I was thinking more like this:

https://www.etrailer.com/12V-Power-A...xoCEAwQAvD_BwE

My camper has USB ports in it but I would not use them to charge a phone personally. My phone has a rapid charger that would not work with the USB port. So what the above link is adds a generic port (cigarette lighter type port) for plugging in the phone charger.

You could of course just use the USB ports you found but you will at some point find that a problem for some things.

[JLeising]

What they said. I use devices like this:

https://www.amazon.com/ALCLAP-iPhone...ateway&sr=8-17

Can charge the phones any time - inverter on or off, generator on or off, with or without shore power. Believe available for essentially all phones and tablets.

FYI

[rockfordroo]

I'd ditch the six 40W bulbs and go with LEDs. A 40W LED will pull only about 20% of the current of an 40W incandescent.

Your six 40W'ers are a total of 240W, so pulling about 2 amps at 120VAC. This means about 20 amps at 12VDC, plus losses in the inverter.

Since you shouldn't use more than 50% of your battery, your 2 90 amp-hour batteries (180 amp-hr total) are really only good for 90 amp-hrs. So you'll need to shut off your lights after 90/20 = 4.5 hrs (ignoring the palm tree and charging phones).

Going with six 40W LED's would drop your 12VDC current 20% to about 4 amps. Now you can run them for 90/4 = 22.5 hrs.

[JLeising]

Originally Posted by rockfordroo

I'd ditch the six 40W bulbs and go with LEDs. A 40W LED will pull only about 1/8 to 1/10 the current of an 40W

See the third post (by the OP) above. Believe he has already done this.

[rockfordroo]

Originally Posted by JLeising

See the third post (by the OP) above. Believe he has already done this.

Yeah, I missed that he changed his lights. But now he could have used a smaller inverter.

[HappyCamperCanada]

Yep. I switched to 8w led bulbs. I could probably get away with a smaller inverter but I'll keep the 500w in case I need to power more stuff down the road.

[chriscowles]

Originally Posted by HappyCamperCanada

Yep. I switched to 8w led bulbs. I could probably get away with a smaller inverter but I'll keep the 500w in case I need to power more stuff down the road.

Does a 500W inverter itself have a higher load than a 300W inverter, independent of what you power with it?

The LEDs tree and patio lights have a converter to run off 110v. Using an inverter to convert 12VDC to 110VAC, only to convert that back to 12VDC, is inefficient. Are there 12VDC lights available for the same purpose? Would they be more efficient.

[Bob414]

Generally Speaking "YES"!

Bob

[HappyCamperCanada]

So the first night I ran the patio lights and palm tree off the 500W inverter for about an hour. Used some inside lights, radio, and the outside LED awning lights a bit and checked the batteries the next morning. Still had a 95% charge. Hooked up the 50W solar panel and had 100% in a couple hours. Next night and remaining nights I ran them about an hour to an hour and a half and used inside lights a bit and the furnace for about 45 mins to take the chill out. The lowest the batteries got was 80%. Each day I used the solar panel to recharge batteries back to 100%. Luckily we had lots of sunny days! So I guess I answered my original question somewhat. The only way to know for sure is to try things out. Btw, I used a cigarette lighter USB charger in my tow vehicle to charge cell phones. The inverter has USB charging ports but I didn't bother.