Power Inverters

750watts might be small for the fridges compressor, maybe take a look at the power rating label on the back of the fridge see if it lists the start up wattage. IF it doesnt list it to be safe if you havent already bought the inverter call the manufacture of the fridge. If you already have the inverter then test it out hopefully it works if it doesnt it will probably just shutdown in safe mode.

 

My boyfriend bought a little gizmo last summer that can answer a lot of questions of actual load vs. what's listed on the label/box... it's an "AmWatt Appliance Load Tester." I started plugging in the stuff I have here to see how much each item takes, then I put a little sticker on each item, with a penned total of the highest power drain the gizmo showed. This way, I figure I should know what has to be unplugged/turned off before something else powers up.
A question I have, though...I know the inverters tell continuous and peak wattage, but how long does the unit allow peak draw before shutting down? One second? Ten?

 

Maybe 2 or 3 seconds. Most devices will draw power in spikes, or peaks, like when they first start up or start doing whatever they do. That's what peak power ratings are supposed to do, account for that surge. Whatever the maximum peak is for your device(s) is, you want a power source that can provide quite a bit more peak power than the device requires. Cutting it too close will lead to dark nights in the cab stabbing various objects with pointy things in frustration. Trust me, I've been there.

 

The other thing to keep in mind, is that voltage from an inverter is a modified sighn wave...and the voltage/ampage needed to start a motor will vary from the readings used with a "kill-a-watt" voltage meeter. It is a good estimater, but be sure you have extra watts from the inverter....nothing kills a inverter faster than running them at max voltage...makes heat...and cooks them quick.

 

Where do I look to see if truck has a built in converter. It's a 2005 w900

 

Underneath the bunk is a good place to start.

 

I'm not really happy with the invertors today. And I'll give some examples, but first I have to mention that I do have two invertors in my truck. One 2500W used only when I use microwave, laser printer, water boiler etc and the other one max 300W for laptop and small gadgets.
- Road Pro 300W almost brand new the fan stopped working after one week I bought it; now it gets hot like hell and I better throw it before starts to melt and damage other things on my truck
- Power Drive 150W; I replace one every 6 months
- Cobra 400W stopped working after one year, I bought exact same one and after one year stopped working
- Cobra 1500W worked for 1 1/2 years after that died
- Sima 200W (I can't find it anymore) worked hard for 4 years then died
- Road Pro 2500W is still working after 6 years. It has one issue tho: it wont work if outside is very cold. So I uninstalled and moved it from the tool box inside the sleeper. The iron is still working great.
-PowerLine 200W (from Walmart) stay away; the fan was incredible noisy and was all the time hot.

I tried more brands and powers but I dont remember every single one. I wish I could find a reliable 250 - 300W inverter that will last at least 5 years. I don't care how much cost.

As I said I use two invertors coz I've been told (not sure if is right or wrong) that if I use the big invertor all the time I will kill the batteries two times faster than if I use a small invertor all day and use the big one only when need muscle.

 

My cobra 800 is still going strong. The fans in these things are notoriously cheap but easy to replace with better ones. Take them apart and look. Any fan that fits in there will work. Heck, we bought a 2000 watt home theater amp and the first thing we did was open it up and replace the noisy, cheapy stock fans with a bigger single computer fan. Runs cool and quiet.

 

kajidono, where can I find fans to replace on my invertors ?

 

Faaaaans: https://www.google.com/webhp?source...sb&fp=1b470fcc170f7fec&ion=1&biw=1537&bih=815

All you really need to do is crack it open, get the fan out, measure it in mm, and search for a replacement. Unless you get lucky and can look that up online. We have accumulated so many old, outdated computers and parts over the years that I can always find a good fan laying around on some shelf. Those powered coolers use the same kind of fans.

Something like this one would most likely fit into a small inverter: http://www.google.com/products/cata...=X&ei=XiP-T72eCYmmrQHAvLyLCQ&ved=0CJcBEPMCMAU

Don't worry about the plug being different if you can't find the exact one they used. Just cut the wires, match the colors, and connect them properly with tape, connectors, or whatever you prefer. You'll want a fan with the same number of wires as the one you pull out. There should always be red for power, black or some variation for ground, and if it has a third wire, that's a speed control. Usually that's integrated somewhere on the circuit board so it will use the two wires.