Inverter for 240V Power Tools?

joliette

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I am planning to do a refit whilst afloat this winter. I would like to run some of my 240V power tools on board such as my 650W electric drill.

I thought about buying a small petrol generator, but then wondered if an inverter would be a better / cheaper option, as I could install this permanently onboard. Would a 1500W inverter be up to the job? I was thinking of running the engine to recharge the batteries when using the inverter. Would there be any advantage in paying more for a pure sine wave inverter, if I'm just running power tools off it?

If anyone has any experience of solving this problem I'd appreciate your advice. Thanks
 
If you are running an old fashioned straightforward "on & off" power tool then any type of current should be alright, but most modern power tools have some form of electronic speed control and other electrickery inside, so I would be wary about how they might respond to a mucky non-sine wave current.

My recollection is that invertors are not overly efficient and combined with this, if you are doing lots of work onboard with powertools, lighting etc you will very rapidly crucify your battery's charge, unless you have a massive bank available, & then you have to consider how to charge the batteries back up again by either running the engine or via a shore-powered charger: I would suggest that you'd be better off running the tools straight off a generator.

Of course there's always the modern safe choice of investing in some decent power tools with rechargeable li batteries and a couple of spare batteries- no problem with power supplies and no risk of electrocution!!
 
You can buy a 2-stroke 700w generator for under £70 new which will run a power plane, jigsaw, belt sander, mini grinder, electric drill, power file, orbital sander etc as well as your TV! Fuel consumption is less than 1 gallon per day and it won't bugger your batteries and is probably cheaper than a cheap inverter. It also has a 12volt x 8amp charge capacity running side by side so can charge your batteries whilst you sand the hull!

Bit of a no-brainer then?

There are several on E-bay, they're all pretty much all the same, I've had one as a spare for a couple of years, (£39.00 in Woolworths believe it or not!) in case my more expensive 4-stroke went tits-up but it's so efficient I've taken to using it all the time.

Otherwise, Aldi are doing a 3.2kva one on wheels for £149.00 at present, check out their offers. I've also had one of those for a year or so, wonderful bit of kit, great for welding, jet-washing and any power tool you might have.
 
I have both a small generator (1kw) and a 1000w inverter (Maplins ~£70). I always use the power tools for bits and pieces on the Yacht but i cant remember the last time i used the generator; too much trouble. Using the inverter its much easier.
 
I have some battery operated tools but I find the batteries run down very quickly and they're not as powerfull as my 240V tools. There are certainly some cheap little generators on eBay. If I use an inverter then I'll have to run the engine to recharge the batteries, so I may as well run a generator, particularly if it's going to cost less than an inverter!
 
Might be worth checking what voltage your battery tools run at. I bought a 12v battery drill with the intention of when the batteries got nackered (as they did after a year) hard wiring it to a deck plug. I did that with enough cable to get all over the boat. There is some voltage drop (didn't want too heavy a cable) and next time I'd use a 14v drill maybe. But anyway, it works a treat, and is great to have unlimited drill power anywhere without any complicated setup. Maybe another option to consider, and probably the cheapest solution.
 
A modern inverter should be at least 80% efficient but remember the current it'll take to run it.

Assuming you've got a 12 volt system this will mean 1500/12 so 125 Amps if it's 100% efficient. Bung in an 80% efficiency factor and you end up with 156 Amps if my calculations are correct. If you've got 3 110 Amp-Hour batteries you'll get no more than one hour out of them if they're fully charged and in very good condition.

I'd say definitely get a PSW model. As mentioned it's difficult to tell exactly what has an electronic controller in it these days but a heck of a lot of stuff does. Apart from anything else you'll need PSW for a Microwave, TV/Radio/Hi-Fi and even anything other than a basic battery charger. Just the knowledge you can plug in anything knowing it'll work and without risking damage is enough for me (having blown up the other half's sacred hair straighteners on a charter boat I can assure you this is worth it!!).
 
I was using a 600 watt generator running from one of those boost starter packs last week whilst afloat.

It happily ran a 700 watt jigsaw for suficient time to enlarge two 4" diameter holes to 4 1/2" through the deck (8mm grp then 40mm wood).

It was to replace a pair od basic vents with solar powered ones.

I would not want to draw a steady 50+ amps from a boat battery.

Iain
 
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