Converting a 120V Leaf Blower to 20V Battery Power

[TheBar]

I love unusual projects even if they aren't very practical. This is somewhat practical. Years ago I bought a small 120v leaf blower to keep in the RV. I use it to blow dirt and leaves away from the door to keep them from being tracked inside. But it requires an extension cord so it isn't ideal. I ran across this video of a guy converting his 120v corded snowblower to use a lithium drill battery. I had some old Black and Decker 20v drill batteries I don't use anymore. I tried this and the 120v blower actually runs good on 20v. It doesn't run as fast on 20v but it is fast enough. I will be cautious not to overheat the lithium battery since we all know what happens when they catch fire For the couple minutes I need it the battery doesn't even get warm.

 

[DonTom]

My leaf blower is battery operated. If you wanted such, why didn't you buy a battery operated one years ago as I did? This is the one I own. I have many items that use the Bauer 20-volt batteries such as my water pump, several saws, fan, drills, weed cutter as well as my leaf blower.

Was it just to find a use for your old batteries?

FWIW, I also own a few old Black & Decker 20V batteries. They are not the same as the Bauer batteries, physical differences.

-Don- Tonopah, NVx

 

[TheBar]

My leaf blower is battery operated. If you wanted such, why didn't you buy a battery operated one years ago as I did?
-Don- Tonopah, NVx

You mean they actually make cordless tools? Made by Tesla, right? Well, gosh durn, what'll they think of next?

When I say years ago I'm saying 1980's before cordless leaf blowers were a thing. As I said I love to experiment with unusual projects even if they aren't practical. I mainly wanted to see how a 120v AC motor would run on 20v DC.

 

[John From Detroit]

Another option is an inverter... YOu can get small inverters that run on 12 or 24 volt I suspect 20 would run them too. Mostly MSW just make sure they have the watts to blow baby blow.
A belt pack or shoulder bag of some kind... I have a horrible freight tool box with two 12 volt LiFePO4 batteries (10 and 20 AH) for radio use. I store an inverter, and the charger and some other useful stuff in the lift out tray. This is not a "Walk about" (it would be with a smaller case a shoulder strap and just one battery) but a lug to table sit down and plug in radio system

 

[DonTom]

Another option is an inverter..

Such as one of the portable HFT's power stations that all have built-in pure sine wave inverters. I have the smallest one, only good for 350 watts (double that for starting power), only 294 WHs, but a lot more handy than I ever expected. I bring it on all my RV trips. It also has 100W USB-C and two 12W normal USB and a 12V ten amp outlet.

You can get them up to 2KW.

-Don- Tonopah, NV

 

[NY_Dutch]

Such as one of the portable HFT's power stations that all have built-in pure sine wave inverters. I have the smallest one, only good for 350 watts (double that for starting power), only 294 WHs, but a lot more handy than I ever expected. I bring it on all my RV trips. It also has 100W USB-C and two 12W normal USB and a 12V ten amp outlet.

You can get them up to 2KW.

-Don- Tonopah, NV

"Normal" USB is 5 volts.

Oops, I mis-read it. I thought the 12V outlet was USB, but obviously the 10 amps says not.

 

[Gary RV_Wizard]

I've got a 1200w portable "power station" (integrated inverter & lithium battery) that will run that blower nicely. Or a corded drill or sander or...

 

[DonTom]

"Normal" USB is 5 volts.

I know. I said 12 watts, not volts. I assume we all know the normal old USB is five volts USB output. IOW, it is 5 volts @ 2.4 amps=12 watts.

But the new (IOW, abnormal) USB C breaks all the old rules for USB. Much higher current and voltage yet is a lot smaller.

The "C" on my HFT power station can do 100 watts, in or out. IOW, use it to charge at 100 watts DC in, the fastest way to charge it. Or use it for 100 watts DC output.

But . . . do not be impressed yet, because:

"The latest USB-C specification, USB Type-C Release 2.1 combined with USB Power Delivery 3.1, can handle up to 240 watts of power.

This capability is achieved through the Extended Power Range (EPR) profile, which increases the maximum voltage from 20V to 48V while maintaining a current of 5A. To utilize this maximum power, devices require specific cables rated for 240W that include an e-marker chip, as standard cables are typically limited to 60W or 100W. "

Amazing, IMO, from a little "C" connector.

-Don- Tonopah, NV

 

[DonTom]

I mainly wanted to see how a 120v AC motor would run on 20v DC.

So when will you see how your ICE vehicle works with a battery conversion?

-Don- Tonopah, NV

 

[TheBar]

So when will you see how your ICE vehicle works with a battery conversion?

-Don- Tonopah, NV

I watched every episode of Vintage Voltage where ICE cars were converted to EV. My 73 pickup is a Club Cab with an 8' bed weighs 4,700 lbs. I couldn't haul anything with the bed full of batteries. Someday, but today is not that day.

 

[TheBar]

I've got a 1200w portable "power station" (integrated inverter & lithium battery) that will run that blower nicely. Or a corded drill or sander or...

This post had nothing to do with powering a leaf blower or gadgets like inverters. This was the science of finding an AC motor will run on DC without any converter.

Brushless DC motors weren't even invented until 1962. When I was 12 and rewiring slot car motors for higher RPM I was told DC motors would not run on AC and vice versa.

When I was 12 I was smart enough not to plug my DC slot car motors into an AC wall outlet. At the age of 74 I'm stupid enough now to try the same in reverse. But hey, no fire or explosion!
.

 

[John From Detroit]

So when will you see how your ICE vehicle works with a battery conversion?

-Don- Tonopah, NV

The original Saturn car.. Yes there was a Saturn before GM conscripted the brand name.

Well it too was a GM specifically a chevy NOVA with a conversion kit.
They pulled the ICE motor and tranny and drive train and installed an all Electric one with standard Automotive type Lead acid batteries to power (most likely a truck load of GC-2's in series/parallel)

I must say I was interested but $$$ poor at the time.

 

[Gary RV_Wizard]

This post had nothing to do with powering a leaf blower or gadgets like inverters. This was the science of finding an AC motor will run on DC without any converter.

Yeah, I got that. Mostly an exercise in curiosity. But the thread title is "Make 120v corded tools cordless" and the modern power pack is a simple & effective way to do that. And risk-free as well.

 

[Lou Schneider]

Since motors have less resistance at lower speeds it would be interesting to see if the current remains within spec when they run more slowly at lower voltage. The mechanism is "counter EMF" where the motor essentially becomes a generator at speed, opposing part of the incoming current. Same mechanism that provides regenerative braking. Lower speed = less counter EMF. This is also why they draw the most current at locked rotor, 0 RPM. There's no rotation to generate the counter EMF.

 

[John From Detroit]

Since motors have less resistance at lower speeds

Uh the word is not resistance but impedance however works out the same

 

[DonTom]

Uh the word is not resistance but impedance however works out the same

DC motor. Therefore, no difference.

Not much inductive reactance with DC.

-Don- Reno, NV

 

[John From Detroit]

DC motor. Therefore, no difference.

Not much inductive reactance with DC.

-Don- Reno, NV

NO it's still impeadence Resistance only applies if the motor is stalled.
But as I said the math is the same only the label is different.

Oh well looking out my window camera.. Oh what a beautiful morning but it's is chilliy outside
Thermometer says 37 But the camera is inside (on the inside of the door/wall)

 

[DonTom]

NO it's still impeadence Resistance only applies if the motor is stalled.
But as I said the math is the same only the label is different.

Oh well looking out my window camera.. Oh what a beautiful morning but it's is chilliy outside
Thermometer says 37 But the camera is inside (on the inside of the door/wall)

Running, often called "Inductive resistance" but perhaps "inductive reactance" would be a better term, but still, take your pick.

IOW, I wouldn't say Lou is incorrect for calling it "resistance."

You're just being picky.

-Don- Gold Run, CA (here reverse these numbers, from 37° to 73° F at 0730 hrs, kinda warm already),

 

[Larry N.]

Running, often called "Inductive resistance" but perhaps "inductive reactance" would be a better term

Impedance does, in fact, resist in most situations, so it is a complex form of resistance.

 

[DonTom]

Impedance does, in fact, resist in most situations, so it is a complex form of resistance.

Yep, I think of impedance as "AC resistance".

Even for a pure DC battery:

"Battery impedance is a measure of a battery's total opposition to alternating current (AC) flow, combining both internal resistance (ohmic resistance) and reactance (capacitive and inductive effects). It is typically measured in milliohms (mΩ) or micro-ohms (µΩ) and serves as a critical indicator of a battery's State of Health (SoH) and power capability. "