Which inverter?

[kex02611]

Hi guys! Stoked to be a new owner of a great van. Just wondering what inverter to buy to charge up basically a laptop and camera battery from installed second battery? I was overwhelmed by the choice at Walmart!

 

[Trebor English]

I got the 400/800 model from Harbor Freight. They are $26. They are not sine wave. They are MSW, modified square wave. Mine has worked fine with everything I have plugged in. I used it with a jig saw to cut the 14 inch square hole in the roof for the MaxxFan. It works my corded drill. I use it for my electric shaver. My Haier 1.7 cube fridge (with lots of added insulation) works.

I have an ancient netbook that actually takes 12 volts DC. Most laptops use 19. You can search on Amazon for a car charger. They might have one that lists your computer. It is more efficient to convert 12 to 19 than to convert 12 to 120 AC then convert that to 19.

 

[bullfrog]

Some battery powered devices will charge only with that manfacturer's charger as it has to be reconized by the device. Some only offer 120 volt AC chaargers. Be carful what you buy as using a 12 volt charger is more efficient. If you must use an inverter then only power it when actually charging and get the smallest one that will for sure power the chargers by comparing wattages. Watts equals amps x volts. My 120 volt laptop charger uses 1.5 amps so 180 watts, my phone can be charged with a 12 volt charger but if I had to a 120 charger uses less than 1 amp so 120 watts so if using both at the same time 300 watts. Be aware doing this would most likely use more amperage than you vehicles accessory plug in is fused for. I would highly recomend wiring the inverter with a fused larger guage wire and switch(you could just pull the fuse when not in use) directly from the nearby battery. Some computorized devices require a pure sign wave inverter to function so check for that before buying an inverter. I bought 350 watt pure sign wave inverter for $103.

 

[LoveCareThinkDo]

I have just recently used my Kill-A-Watt to measure the power usage of both my laptops together, doing the most power taxing things I could find. One was charging after being used unplugged, and one was defragmenting two external drives, both at full brightness. Together they used a maximum of .85 amps, My wall is putting out about 123 volts, so that is a grand total of 104.55 watts. When I was urban boondocking before, I picked up a Black & Decker 120 watt inverter from Home Depot for about $20. So, that is more than enough to run both my laptops at the same time. It's a tiny little thing and it takes up almost no space. It has an automatic cut-off when the battery gets below 11.8 volts, but I think that is too low, so I didn't depend on it. I was even able to run my Dremel tool off of it, as long as I had my engine running. 

Because larger inverters use more "overhead" power, the recommendation is to use the smallest inverter necessary to power the devices connected to it. So, I recommend you just get this tiny little inverter to start with. It is inexpensive, and it worked well for me. If you find you need more later, you can get a bigger inverter. Having a small collection of inverters, of various "sizes" is a good idea. 

Even after I get solar, I will still use this little inverter for charging some small things as I drive.

 

[wayne49]

Idle is idle for inverters.

Same basic electronic circuitry is running in any inverter when there is no load. I compared a cheap 150 watt MSW to a Samlex PST-1000 watts PSW. Same DC draw at idle. Around 0.85 amp.

 

[LoveCareThinkDo]

Idle is idle for inverters.

Same basic electronic circuitry is running in any inverter when there is no load. I compared a cheap 150 watt MSW to a Samlex PST-1000 watts PSW. Same DC draw at idle. Around 0.85 amp.

Interesting. That is almost the opposite of what I have read, just about everywhere. Of course, it is also possible that the cheap 150 watt unit was just super inefficient. .85 amps is what both of my laptops draw together, when they are working hard. But it does go to show that you gotta actually measure everything because estimates can be way off.

 

[Almost There]

Before I had a big battery system and all the bells and whistles I needed a way to charge my cell phone and laptop.

I picked up a 120 W Black and Decker plug in unit at Home Depot for around $20.00.

Plug it in to an accessory outlet on the dash, charge what you need while you're driving, unplug it when you don't need it.

I still keep it for charging stuff while I'm driving.

Inexpensive, easy to use, reliable and doesn't draw down the battery when it's not plugged in.

Now that I have a full electrical system, I have a 400W Pure Sine Wave inverter hard wired in to the electrical system with a lighted on/off switch so it can be turned off when it's  not in use. It's connected to  2 outlets in the van so I have a plug where I  need it. But I have a fairly fancy system that has been the subject of much envy...

 

[tx2sturgis]

Idle is idle for inverters.

I just recently bought a GoPower PSW inverter because it has a 'power saving' mode, very low current draw when idle. It has an adjustable setting for 'wake-up' threshold.

I will report on it after I get it installed and can run some tests.