Running 20v equipment on 24v.

Evil Spirit

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As a disabled senior (and on fixed income) it get's harder every year to do yard maintenance. Had to quit using gas string trimmers years ago, due to the weight. Since my mobility scooter has a large 24v amp/hr power supply, I was considering using it to power a string trimmer for yard maintenance. And since there are tons of 18-20v trimmers listed daily on the sales sites for cheap rehoming, usually due to the batteries going bad, my thoughts were to grab one and try to run it on the 24v of the scooter batteries. Thoughts? Would the over-voltage quickly fry the motor, or is there some "forgiveness" in the voltage rating that would allow moderate usage without the "what's that SMELL" result? There are some 24v trimmers out there that are reasonably cheap without the battery and charger, but the $10-15 garage sale units are abundant and new ones are +/-$75-100. So - think this will work without me being nicknamed "Sparky"?
 

MowerMike

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The simple answer is no, you should not run a DC motor above its rated voltage. Will it explode and kill you, no of course not. It will simply overheat and die. You might have a 10% safe overvoltage, which would get you to 22 Vdc, but you are proposing a 20% increase, which is too much IMO. Also, connecting your power supply to the trimmer may be tricky, you will need to jury rig a cable with adapter connectors specific to the model trimmer that you are using. ATM, I don't know what to suggest, other than trying to find a used trimmer that includes the battery and charger.
 

sgkent

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it isn't just the volts but the amps needed too. Then there are the connectors that are unique to each battery pack. While it can probably be done, someone who has to ask how isn't going to engineer a safe solution.
 

Evil Spirit

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I think I might have an old B+D 18v trimmer in my shed that would make a good "sacrificial lamb" for this test. If - or when - it fails, then Greenworks has a 24v trimmer fairly cheap if bought tool only.

Called a friend that ran VW engines in sand rails and dune buggies. He said he commonly ran 6v starters in his 12v motors without issue. The rest of was electrical system was proper 12v components.

As to the connector issue - probably no issue there. I don't necessarily need to supply the power thru the battery port terms - power can be introduced in many different points in the system. The feed power connectors could be the 30 or 50a Anderson ones, or ones from the 1/8 scale RC cars.

Thanks for the replies.
 

sgkent

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I think I might have an old B+D 18v trimmer in my shed that would make a good "sacrificial lamb" for this test. If - or when - it fails, then Greenworks has a 24v trimmer fairly cheap if bought tool only.

Called a friend that ran VW engines in sand rails and dune buggies. He said he commonly ran 6v starters in his 12v motors without issue. The rest of was electrical system was proper 12v components.

As to the connector issue - probably no issue there. I don't necessarily need to supply the power thru the battery port terms - power can be introduced in many different points in the system. The feed power connectors could be the 30 or 50a Anderson ones, or ones from the 1/8 scale RC cars.

Thanks for the replies.
classic case of too much time on someone's hands.
 

Evil Spirit

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classic case of too much time on someone's hands.
Or work around a disability that doesn't allow me to use conventional yard tools.
If I really had too much time on my hands, my post count on here would be higher.
 

sgkent

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I have a disability too but I use the battery charger. Hardly worth dicking around with things, and I gave up carrying cords around a long time ago.
 

Charlie8d

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I would not try to do that. I own an assortment of Greenworks tools, & love them. Mine are all 60Volts. There is a sale going on right now. Also, if you sign up on their website, you will et 10% off & be notified of upcoming sales.

 

MowerMike

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I would not try to do that. I own an assortment of Greenworks tools, & love them. Mine are all 60Volts. There is a sale going on right now. Also, if you sign up on their website, you will et 10% off & be notified of upcoming sales.


I would not recommend buying directly from Greenworks. I had my credit card stolen on their website back in 2020. See post #48 of this thread >>> https://www.lawnmowerforum.com/thre...0-volt-outdoor-tools.41300/page-5#post-380051
 

Charlie8d

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I have not had any problem with buying directly from Greenworks.
 
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