Ryobi trimmer 150r Lipo Upgrade?

[mushymelon]

Could someone recommend a battery and charger for the upgrade
I would like to go to 18v if possible a little more Go would be nice.

Heres the specs.

Ryobi 150r 12v electric weed eater

Original battery is a 12v 8ah gates SLA

View attachment 3

Heres the switch



There is a thermal overload switch. I think a bypass is in order here.



Image of a replacement motor.
I have not opened up the motor housing yet but it should be similar.
I dont know the specs.



Im planning on keeping some battery wire and the connectors external for easy charging.

Can the switch handle an extra 6+ volts ?

Can the motor handle and extra 6+ volts ?

What charger and battery would you recommend ?


I am in ontario is there anything restricting delivery here?

 

[E-racer]

hahahaa I cant wait to see this. Ive been wanting to build an 80-100/lipo weedwacker since i finished my scoot and felt how much power that motor has.

 

[BLUESTREAK]

I just fixed my WORX trimmer that had 18vilt battries and both battries died in (1) month and thay were lithium but way too small. I used (5) 3.3 THUNDERSKY cells and it's just perfect and I made a shoulder strap for the battries. I use (1) 12volt and (1) 3.3 voltpeaks charger.

 

[amberwolf]

The switches and stuff'll work fine, but that little motor gets really f'n hot even on the 7Ah SLA it comes with (which lasts like 20 minutes, maybe, till it won't spin fast eough to cut grass).

So be careful so you don't melt the plastic case around the motor, or melt the string head off the motor shaft. My casing is damaged now from the motor heat and I had to shim it to keep it from shaking the whole trimmer apart.

If you were really wanting to lipo a trimmer, the wall-powered Ryobi (137r? I forget) would be a really nice choice, if you can get 120-150VDC or so on it. :lol: I loved mine till I burned out the motor with Phoenix summer heat and trimming my whole lawn with it for years. I loved it so much that when I saw one at Goodwill on their half-price sale day a couple months ago, I spent money I shouldn't have on it, even though it was missing the trimmer spool and button (because I figured I"d pull that off my old one, but the nut is rusted on there now and I can't get it off to use it...and cant buy a new one. )

 

[texaspyro]

I'd go LiFePO (probably 4S Headway) rather than LiPo. LiPo cell voltage drops as they discharge and LiFePO stays rather constant. Since the whacker has no controller/voltage regulation the LiFePO cells will provide a more constant motor speed and more consistent cut. Also should have longer cycle life and be more robust (you probably won't have a BMS/LVC system).

But then, even a 3S 5 Ah LiPo pack will outperform your old lead lump and be a whole lot lighter... makes for a rather tempting (and cheap) upgrade.

 

[dogman dan]

3s hobbyking lipo would be great for that. FWIW overvolting a weedwhacker may just make you burn up string faster. They work best when used at the lowest speed which still cuts effectively, and only revved up for the tougher cutting when you come to some.

You'll need to know when to stop of course, you can't just stop when it bogs down with lipo or lifepo4. So you need warning buzzer lights, or even just a harbor freight voltmeter to let you know when to stop for the max cell cycle life.

I put both my 24v B&D lawnmower and 24v B&D trimmer on 6s lipo and it is truly SWEET! 8) The original mower sla's were total junk even brand new. Now the mower pushes as easy as an empty baby buggy and never bogs down on thick grass. The gradual voltage drop as you mow or trim is not a big deal, It's nothing compared to the original voltag sag of sla's.

 

[auraslip]

I put both my 24v B&D lawnmower and 24v B&D trimmer on 6s lipo and it is truly SWEET! 8) The original mower sla's were total junk even brand new. Now the mower pushes as easy as an empty baby buggy and never bogs down on thick grass. The gradual voltage drop as you mow or trim is not a big deal, It's nothing compared to the original voltag sag of sla's.

What sort of run time are you getting with this? An all electric setup would be great for my lawn care business, but I'd need probably two hours of run time for the mower.

 

[dogman dan]

Run time would simply depend on the size of your pack. I can't tell you much yet, because my grass is about 1/2 inch tall. I did some testing last summer with thick grass and it worked as you would expect, twice the performace per AH compared to lead. That was at 5s, so I was undervolting and bogging down. Still worked better than the saggy sla's.

Taking a guess, I'd say 4 6s 5 ah packs would mow a typical yard. So get 8 and a fast charger you can plug in while mowing. Charge 4 and mow with the other 4. The string trimmer works a looooong time on one 5 ah pack. The nicad pack the trimmer came with is only about 2 ah.

One thing to consider though, is using a cheap B&D brushed motor lawnmower to mow on a commercial scale. Just a cheezy brushed motor inside the thing. It's fine for me, I'll never use it more than 20 min at a time. Mowing two 1/2 acre lawns in one hour would likely melt that cheap brushed motor.

Really cool though, would be to hack a brushless mower using the RC motor stuff. AC mowers are cheap used though, if you know how to hack one to run on DC. I've read about it, but it's been way over my head to understand.

 

[hydro-one]

I see a mow head. Turnigy motors say one on each side of the back wheel of ebike. one in back behind wheel. carbon fiber spars allow the positioning of the motors/mower head. now you just ride you bike over the lawn, extend the arms, and giver!!! the distance to ground of mow head is determined by ultrasonic sensors. servos control the tilt and hieght of blades.

 

[auraslip]

AC mowers are cheap used though, if you know how to hack one to run on DC. I've read about it, but it's been way over my head to understand.

I have an AC weedeater. IIRC you can just stack enough cells to equal 110v. That wouldn't be that bad. Put the cells in a back pack with a built in cooling system, water cooler, and ipod+speakers and I'd be set

 

[mushymelon]

Ok thanks for the input
maybe one of those hobbyking life4 batteries would do the trick.
I have a small yard so 20 -30 min tops maybe some extra cooling holes in the plastic.

I have looked at new lithium trimmers, what a f'n rip off, Big money for 1 - 2 ah range at 18v USELESS

If i upgrade the battery chemistry maybe 12v would do ok because this thing worked great hot off the charger.

 

[mushymelon]

Maybe something like this

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14070

What type of charger would I need

 

[dogman dan]

Any of the cheap slow 50 watt chargers would do for you. Not like you'd need to charge but once a week. This one has a built in power supply, but any of the others would work with a 5 amp 12v power suppy. http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6478

The lipo chargers have settings for lead, nicad, lifepo4 etc too.

 

[mushymelon]

Any of the cheap slow 50 watt chargers would do for you. Not like you'd need to charge but once a week. This one has a built in power supply, but any of the others would work with a 5 amp 12v power suppy. http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6478

The lipo chargers have settings for lead, nicad, lifepo4 etc too.

Great thanks.

 

[999zip999]

Please go green get a goat, free fretilizer and milk for your coffe.

 

[dogman dan]

No way, when fall came you'd never get the kids to let you eat the goat. Then you'd be stuck with this huge mean goat all winter, buying him feed till the lawn grew again.

Rent a goat, that's better. The city just did that to clear weeds from a storm ponding area, and it was a huge sucess. Seriously, rent a goat.

 

[999zip999]

I forgot the goat meat I had in mexico at my friends uncles house, He was the first 6 foot 6in. Mexican I saw.

 

[amberwolf]

Not all AC-motor weedeaters or mowers can be used on DC. Most can: if they have brushes in the motor, they'll work on DC. IF they have no brushes adn there's a capacitor in there, then they won't work on DC as they are AC induction motors adn eneed the AC frequency to make them spin.

 

[dogman dan]

Ahh, that's the difference. I could never remember what I read before. Chances are the typical 50 buck B&D Corded mower is also just a cheap brushed motor.

 

[amberwolf]

Probably; mine was (until the motor disintegrated due to magnet coming apart and cutting the windings to pieces). Pretty similar in design/etc to a typical cheapy treadmill motor.

But the AC induction motors are also cheap and actually seem to be found on the even-cheaper-than B&D stuff; the no-name one given to me aftter it began shaking itself apart is like that.

 

[dogman dan]

How would you know the difference by looking, if you bought a cheap used electric AC lawnmower? I got half price on my DC mower, and even then it was $200. But I see the electric AC version at the flea for $50 all the time. Would it just say so on the side of the motor?

 

[amberwolf]

it might, but probably not. Maybe on the motor itself, but if you have it open that far then it is probably easier to use these two easy ways to tell instead:
--DC-capable motor has brushes and commutator, usually easily visible thru the end at the top.
--AC-only induction motor has a starting/run capacitor that generally is a bare aluminum can with three leads, commonly 3-5" long and 1-2" diameter. Sometimes covered by a plastic housing to keep the contacts isolated, sometimes not.

Also the AC IM won't have windings on the rotor/armature in the center, just a solid-looking core, with windings on the outside that kinda resemble those of a hubmotor's inside windings.

The DC-capable motor will have windings on the rotor/armature, and either magnets or windings on the outside.

 

[auraslip]

Lots of sub-$100 electric mowers on craigslist. Probably cheaper even if you could find a broken one.
I bet they're lighter than a gas unit which would be a plus for me and my trailer.

They probably don't have the raw power to tame serious overgrowth though.... Still would be great to have....

 

[amberwolf]

They *can* have the power....as long as you cool the motor properly after the upgrade.

 

[999zip999]

The mow I do, The mow I like.