A little help with the math, please

[virtualy]

I would like to power an electric chainsaw (15A). So, I'm looking at converting 36 volts DC to 12 volts DC, then inverting 12 V DC to 110 V AC. I need to end up with 110 VAC, 3300 W peak, 1650 W continuous. Possible?

Thanks.

[yurtle]

That's a pretty big inverter, but I guess it's possible. The largest inverter I have is a 750 watt, and it's a big ole coil and core type and weighs a ton. I'm sure they have 'em. Just gotta Google for it, then see if your poor 36 volt to 12 volt converter/reducer is big enough.

If this is something you plan on doing a lot, maybe you should go straight from 36 volts to 120, and skip the 12 volt step. I'll bet folks who are doing solar, wind, etc. do this all the time.

Also, JohnnyB will probably be along and offer better advice, but you may be able to power the chainsaw motor with DC, possibly giving you a more efficient dc to dc converter.

Ever thought of buying a gas chainsaw? It may be cheaper in the long run, and even a cheap used one will run circles around an electric one.

[JohnnieB]

It is possible, but it's not practical.

Even at 100% efficiency, an inverter will need 137.5A at 12VDC to produce 1650W at 120VAC and 275A at 12VDC to produce 3300W at 120VAC.

There are some 36V cordless chainsaws out there and you might be able to feed them straight from the cart's battery pack, or power their charger via an inverter.

A small (3.5KW) gasoline powered AC generator that could be carried in the bagwell might be the answer if you don't want to buy another chainsaw.

[virtualy]

Originally Posted by yurtle

If this is something you plan on doing a lot, maybe you should go straight from 36 volts to 120, and skip the 12 volt step. I'll bet folks who are doing solar, wind, etc. do this all the time.

I'm having solar put on the roof. I'll ask the rep.

Originally Posted by yurtle

Ever thought of buying a gas chainsaw?

Neighbors.

Originally Posted by JohnnieB

Even at 100% efficiency, an inverter will need 137.5A at 12VDC to produce 1650W at 120VAC and 275A at 12VDC to produce 3300W at 120VAC.

And typically EZGO battery banks carry how many amps?

Originally Posted by JohnnieB

A small (3.5KW) gasoline powered AC generator that could be carried in the bagwell might be the answer if you don't want to buy another chainsaw.

Not sure I want to buy a generator just for this application.

Thanks guys. Figured you'd have some answers for me.

[JohnnieB]

Originally Posted by JohnnieB

Even at 100% efficiency, an inverter will need 137.5A at 12VDC to produce 1650W at 120VAC and 275A at 12VDC to produce 3300W at 120VAC.

Originally Posted by virtualy

And typically EZGO battery banks carry how many amps?

About 225AH, which will supply 275A for short periods of time, but the problem isn't the 36V source, it is find a 36V to 12V converter that will put out 275A at 12V.

Other than a long heavy gauge extension cord or a gas powered generator, I have no other suggestions.

[Gonkulor]

I know this will make me seem like a jack** and a D** but the thread title gave me an old thought of my child hood.

Elementary, My Dear Schoolhouse Rock - YouTube

Elementary, My Dear Schoolhouse Rock - YouTube

Sorry but I had to laugh.

[Dave Box]

Here is an interesting video on the same subject. The chain saw part starts at 3:30
https://www.youtube.com/watch?v=zFYpNrbyKCA