# How Long Could I Run a Saw?



## MoonRiver (Sep 2, 2007)

I have some ant eaten 2x4's I need to cut out. No power close by. My battery powered circular saw is too underpowered to cut them. The saw I plan on using is rated at 12 amp/110v. 

I have about 6 2x4's I need to make 2 cuts each in, to cut out the bad sections. Should a 100 ah lithium battery and inverter be enough to power the saw? I think yes, but wanted to double check.


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## Bearfootfarm (Jul 13, 2006)

With a good blade it should only take a few minutes of actual run time.
The blade matters as much as the saw itself.

You're talking about cutting only 42" of material.


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## crehberg (Mar 16, 2008)

I'm gonna be 100% honest here...if I could get to it...I'd use a hand saw before I went to all the trouble figuring all that out.

If you're battery powered saw won't cut em... I guess your set up may work. It may not. There's a lot of variables here....but let us know how it goes!


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## Murby (May 24, 2016)

MoonRiver said:


> I have some ant eaten 2x4's I need to cut out. No power close by. My battery powered circular saw is too underpowered to cut them. The saw I plan on using is rated at 12 amp/110v.
> 
> I have about 6 2x4's I need to make 2 cuts each in, to cut out the bad sections.* Should a 100 ah lithium battery and inverter be enough to power the saw? *I think yes, but wanted to double check.


ROFLMAO.. Yes.. a 100ah lithium battery could probably build an entire shed.


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## farmrbrown (Jun 25, 2012)

Probably, but it helps to know the voltage of the battery too.
I just looked at it quickly, but I think it would run that saw an hour.

https://relionbattery.com/blog/how-to-size-your-products-lithium-ion-battery-for-optimal-performance


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## Murby (May 24, 2016)

farmrbrown said:


> Probably, but it helps to know the voltage of the battery too.
> I just looked at it quickly, but I think it would run that saw an hour.
> 
> https://relionbattery.com/blog/how-to-size-your-products-lithium-ion-battery-for-optimal-performance


Being that the battery is 100ah, I kind of assumed it was at least 12 volts.

For reference, the 20 volt lithium ion drills they sell these days have ~2ah to 5ah batteries and will run a cordless drill for most of the day driving 3 inch decking screws.

Besides, it doesn't even really matter.. The nominal voltage of a single cell LiIon battery is 3.7 volts, so that works out to 3700 watts of power.. In fact, its making me wonder if he really meant to type 10ah instead of 100ah.


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## Bearfootfarm (Jul 13, 2006)

You can find a lot of interesting information at this site
Some of the people there know what they are talking about.:
https://www.solarpaneltalk.com/forum/off-grid-solar/batteries-energy-storage


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## MoonRiver (Sep 2, 2007)

Murby said:


> Being that the battery is 100ah, I kind of assumed it was at least 12 volts.
> 
> For reference, the 20 volt lithium ion drills they sell these days have ~2ah to 5ah batteries and will run a cordless drill for most of the day driving 3 inch decking screws.
> 
> Besides, it doesn't even really matter.. The nominal voltage of a single cell LiIon battery is 3.7 volts, so that works out to 3700 watts of power.. In fact, its making me wonder if he really meant to type 10ah instead of 100ah.


It's a Battle Born 12v 100 ah lithium battery I plan on using for a solar system on/in my van. I was trying to figure out how to get power out to my shed and had just ordered the battery, so it seemed like a good solution.


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## Murby (May 24, 2016)

MoonRiver said:


> It's a Battle Born 12v 100 ah lithium battery I plan on using for a solar system on/in my van. I was trying to figure out how to get power out to my shed and had just ordered the battery, so it seemed like a good solution.


That battery will easily power an inverter that powers a saw.. you could probably build an entire shed on a single charge.


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## farmrbrown (Jun 25, 2012)

MoonRiver said:


> It's a Battle Born 12v 100 ah lithium battery I plan on using for a solar system on/in my van. I was trying to figure out how to get power out to my shed and had just ordered the battery, so it seemed like a good solution.


I assumed 12v but wanted to be sure.
12v x 100amps = 1200 watts
Your saw is 110v x 12amps = 1320 watts

Just about the same.
A 100ah battery will give you 10 amps of power for 10 hours before 100% drained.
Of course none of this includes power loss to the inverter or load conditions.
But you're not going to run the saw continuously but taking cuts of less than a minute apiece, so the reality is you should be able to cut a few 2x4's with no problem and fix your project.


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## wy_white_wolf (Oct 14, 2004)

I think you'll find the biggest hurdle will be overcoming the startup surge of the saw. My DeWalt uses about the same amperage but is slow starting with my 3500w generator. I can only imagine the problems you'd have with that small of a battery hooked to a large inverter trying to start it.

WWW


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