Advice on Power Inverter

[Tkdx00]

I'm looking to get an understanding of what size power inverter to get.
To cover the powertools and a few specific electrical items that would have to tag along, how do I compute what is needed or do I just go for broke and get a 1000, 1500, etc.... ?

If this is covered somewhere...point me to the thread.

[keezer37]

Many corded power tools are 15A. Designed to plug into your typical house outlet. That puts you at 1800W. Check your amp or watt rating listed on the tools. Amps x Volts = Watts or Watts/Volts = Amps

Really recommend cordless and a bank of chargers. But if that's not practical, 1800W.

[Tkdx00]

Many corded power tools are 15A. Designed to plug into your typical house outlet. That puts you at 1800W. Check your amp or watt rating listed on the tools. Amps x Volts = Watts or Watts/Volts = Amps

Really recommend cordless and a bank of chargers. But if that's not practical, 1800W.

I don't want to start rebuying tools.
Cobra 2500 @ Cabela's $250

[bfdiesel]

What are you running?

[mattm01]

Where are you planning to source your power for the inverter from? Main vehicle? Aux? What are you amp hour ratings? Honestly? If you're looking at $250 just for an inverter you might consider a small genny ala the Yamaha or Honda 2000. It really depends on how much tool work you'll be doing.

[Jay H]

I went with a cobra and it's cheap. I have a 400 continous 800 peak. I have it perminantly installed under my dash and it has to have a relay so it is disconnected when the vehicle is off because it pulls 1A when switched off. The thermostat for the fan sucks as it seems to just come on at random, seriously it comes on when its been sitting in below zero winter weather with no load connected and the unit is cold to the touch. I am really glad I opened it up as there were a lot of issues with the assembly, undersized resistors, improperly mounted components, lots of cold solder joints ect. I fixed a lot of that. That said I like having an inverter on board so much I wish I would have gone with a better one.

[Tkdx00]

Sorry I haven't been back to review this. Work and life sometimes get in the way with play.

in any case, my intention here was to get an idea of what inverter would be needed to run a fridge, water pump, tools, lights and some niseatise for the wife in a M101 type trailer without draining the aux batt too much.

[dwh]

Figure a worm drive Skil draws let's say...12 amps. At 120v AC.

So shift the decimal point and it's now 120 amps at 12v DC.

120 amps X 12v = 1440 watts.

So a 1500w inverter would handle it...except it probably won't because the Skil has a huge momentary startup load. Pretty much any other power tool that will plug in to a normal 15a 120v wall outlet will be less than that - except for a chop saw or a welder.


Now as to the battery...

Well, if you have a 120 amp*hour battery, then figure you'll get maybe an hour out of it before it's totally completely flat. Of course, running a battery completely flat shortens its life a LOT, so you probably won't want to do that.


Standard bar type fridge will draw a lot - usually around 11 amps or so...so figure an hour run-time until dead battery. Good 12v DC fridges like ARB, Engel and Novacool are hella more efficient.


Bottom line: Big inverters need big battery banks (anything over 400w is big - a 400w inverter draws up to 34a from a 12v DC supply). Or they need the truck engine running (at high idle speed) while you use them. You'd be better off with a small generator.