Author Topic: Lithium tool battery repair and reuse  (Read 1150 times)

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dnix71

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Lithium tool battery repair and reuse
« on: April 30, 2023, 06:33:23 PM »
Local government here doesn't make money recycling, they do it because they have to. So they are quite tolerant of independent recyclers, aka trash pickers and scrappers. I'm friends with a couple of them and because I have cash and the skill and time to fix some things, they share their findings with me. We all need and use battery powered hand tools and lawn equipment. I do a fair amount of lawn work at home and church and do not really like dealing with gasoline powered equipment anymore. There is too much ethanol in regular gasoline and it goes sour quickly here in the warm humid climate and fouls the carberators, esp. in 2-stroke machines.
At home I went all plug in 120v AC powered because the lawn is small enough. A 100 foot extension cord allows me to mow, sidewalk edge, weed whack and blow from the mains. At church we have 3 acres total land, so that is not practical.

I bought new 2 different leaf blowers (Walmart and eBay) and began looking for spare batteries for extra run time. The 2x20v HyperTough blower from Walmart I have works well but it wasn't made long enough for there to be free batteries to be had.

Ryobi, on the other hand, is sold at Home Depot, and "Black+Decker" is common because of it's low price. Neither brand has a "commercial" division. B&D advertises tool compability with it's 20Vmax line, but it isn't so. Some Craftman chargers will accept B&D batteries but real compatability isn't there. Recently I bought 2 aftermarket 20vMax batteries from eBay for a weed whacker. Both worked when they came in partially charged. Neither would initially charge even though the voltage was a bit low. They worked in a 20v B&D shop blower. Neither would recharge in a Crafstman charger that normally works for B&D. I used a variable voltage lithium battery charger and manually recharged both. Then neither worked in the weed whacker, shop blower or a small B&D hand drill. All had full voltage. The person who gave me shared the tools with me suggested the 20vMax label was intended to be taken literally. After discharging both some, they indeed did work in 2 of the 3 tools, but the drill still refused them.

Now, if they work in some tools sometimes and not other times, it's not the aftermarket battery that's the issue. I permanently fixed the issue with the weed eater by bypassing the circuit board in the handle. I bought a different aftermarket charger for $12 and that works. Bypassing the board means I don't have 2 speeds and a line bump button, but I prefer no drama when I want to use a tool. Off or on. Do or do not as Yoda used to say.

I bought a 40v Ryobi blower and wanted a spare battery only to find they cost more than the original blower plus battery. There are a lot of those batteries available in not working state because Ryobi seems to have the same quality control issues B&D does. I bought 2 "defective, for parts only" from eBay for $36. One new is almost $100. After taking them apart I could only find some light moisture damage but nothing obvious. A bit of searching on the internet turned up where the actual battery ground was. To force charge a battery you usually have to bypass the board to get either the true hot or true ground. One of the plus or minus external charge pins is isolated by diodes on the board. I soldered a short wire to the actual ground inside and ran it out when In reassembled the battery. Now I can easily force charge them without opening them up.

A real Ryobi charger refused both, but at least pretended to check them out before blinking error. After force charging both the Ryobi charger now freaks out as soon as you put either battery in. But both work fine in the blower. So I win this time. Almost $200 worth of spares for $36. The charger is a 42v eBike charger. It won't go over voltage and cost $20 on eBay.
« Last Edit: April 30, 2023, 08:53:10 PM by dnix71 »

Bruce S

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Re: Lithium tool battery repair and reuse
« Reply #1 on: May 01, 2023, 08:46:25 AM »
Good to see I'm not the only one seeing quality issues when it comes to the newer stuff.
In the past I always bought B&D because of their past history of good quality at a fair price.
Just doesn't seem so anymore. I get Li batteries from old laptops, therefore I also bought a battery tester just to make sure they where worth keeping or drop off at a recycler (Home-Depot).
I assemble mine using the spring loaded ends and just replace the old NiCAD batteries in the packs. Even the newer weed whacker motors are no where near what the older units are in terms of solid builds and motors. I buy the parts and just rebuild the old ones.
I built a solar charger a long time ago when I was able to get Ahrs worth of NiMH batteries. It keeps the Li batteries charged just fine.

Cheers
Bruce S 
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Mary B

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Re: Lithium tool battery repair and reuse
« Reply #2 on: May 01, 2023, 12:01:53 PM »
Local government here doesn't make money recycling, they do it because they have to. So they are quite tolerant of independent recyclers, aka trash pickers and scrappers. I'm friends with a couple of them and because I have cash and the skill and time to fix some things, they share their findings with me. We all need and use battery powered hand tools and lawn equipment. I do a fair amount of lawn work at home and church and do not really like dealing with gasoline powered equipment anymore. There is too much ethanol in regular gasoline and it goes sour quickly here in the warm humid climate and fouls the carberators, esp. in 2-stroke machines.
At home I went all plug in 120v AC powered because the lawn is small enough. A 100 foot extension cord allows me to mow, sidewalk edge, weed whack and blow from the mains. At church we have 3 acres total land, so that is not practical.

I bought new 2 different leaf blowers (Walmart and eBay) and began looking for spare batteries for extra run time. The 2x20v HyperTough blower from Walmart I have works well but it wasn't made long enough for there to be free batteries to be had.

Ryobi, on the other hand, is sold at Home Depot, and "Black+Decker" is common because of it's low price. Neither brand has a "commercial" division. B&D advertises tool compability with it's 20Vmax line, but it isn't so. Some Craftman chargers will accept B&D batteries but real compatability isn't there. Recently I bought 2 aftermarket 20vMax batteries from eBay for a weed whacker. Both worked when they came in partially charged. Neither would initially charge even though the voltage was a bit low. They worked in a 20v B&D shop blower. Neither would recharge in a Crafstman charger that normally works for B&D. I used a variable voltage lithium battery charger and manually recharged both. Then neither worked in the weed whacker, shop blower or a small B&D hand drill. All had full voltage. The person who gave me shared the tools with me suggested the 20vMax label was intended to be taken literally. After discharging both some, they indeed did work in 2 of the 3 tools, but the drill still refused them.

Now, if they work in some tools sometimes and not other times, it's not the aftermarket battery that's the issue. I permanently fixed the issue with the weed eater by bypassing the circuit board in the handle. I bought a different aftermarket charger for $12 and that works. Bypassing the board means I don't have 2 speeds and a line bump button, but I prefer no drama when I want to use a tool. Off or on. Do or do not as Yoda used to say.

I bought a 40v Ryobi blower and wanted a spare battery only to find they cost more than the original blower plus battery. There are a lot of those batteries available in not working state because Ryobi seems to have the same quality control issues B&D does. I bought 2 "defective, for parts only" from eBay for $36. One new is almost $100. After taking them apart I could only find some light moisture damage but nothing obvious. A bit of searching on the internet turned up where the actual battery ground was. To force charge a battery you usually have to bypass the board to get either the true hot or true ground. One of the plus or minus external charge pins is isolated by diodes on the board. I soldered a short wire to the actual ground inside and ran it out when In reassembled the battery. Now I can easily force charge them without opening them up.

A real Ryobi charger refused both, but at least pretended to check them out before blinking error. After force charging both the Ryobi charger now freaks out as soon as you put either battery in. But both work fine in the blower. So I win this time. Almost $200 worth of spares for $36. The charger is a 42v eBike charger. It won't go over voltage and cost $20 on eBay.

Ryobi had a battery supplier problem for awhile and did a LOT of warranty swaps. I suspect they "rebuilt" many of the returns and they went to eBay...

I have a bunch of Ryobi tools and had zero new battery problems, all bought the last 2 years. The 40 volt weed wacker does an awesome job on my yard, and the chainsaw is a beast. Cut up an entire decent sized(20" dia trunk) tree with one charge!

dnix71

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Re: Lithium tool battery repair and reuse
« Reply #3 on: May 01, 2023, 01:55:45 PM »
Mary B I also heard that Ryobi made a lot of battery swaps under warranty a few years ago to preserve their name. Both of the batteries I bought from eBay appear to be more than 10 years old, and I suspect the seller would have at least made the phone call for a swap if that was possible. One battery seems to fade a half a bar if I let it sit a while. That probably means a circuit balancer is off spec. Not something I can fix, but 3 1/2 out of 4 is okay for $18 and it takes a little while to fade so I can boost it just before using it.

Both Ryobi bats had hints of moisture damage, like condensation. That will kill any lithium battery dead right away. One of the scrappers I deal with is a sandwich short of a picnic. In addition to being a hoarder, he leaves his tools laying around in the open, in his truck, on the garage floor or just in the driveway. No respect for what could make him money. I got what should have been 2 nice electronic keyboards from him only to discover them full of bugs and unsalvageable. Most circuit board makers don't pot their work anymore. At least you might think lawn tools could tolerate a little water, but it isn't so.

tanner0441

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Re: Lithium tool battery repair and reuse
« Reply #4 on: May 01, 2023, 01:57:28 PM »
Hi

I have stripped and built quite a few battery packs. I have 2 Ryobi drills and an impact screwdriver twice when the capacity seemed low I stripped the cells out and put them through my Opus charger tester and never found a cell that came up to spec. I had a Milwaukee battery pack given to me that was reported dead and on testing the BMS had failed. I removed the cell put them through the Opus and every cell met 2200mAh.

We also have two of the German supermarkets in the UK and I have never had a problem with their batteries when the were selling off their 2Ah battery packs cheap I bought several, stripped the cells out and again everyone was over 2000mAh.

Interestingly they all use Samsung cells so do Ryoby use B grade cells in their battery packs.

Another i found strange  is I bought 3 spot welders for building battery packs before I found one that has sufficient penetration.

Brian

dnix71

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Re: Lithium tool battery repair and reuse
« Reply #5 on: May 01, 2023, 06:16:18 PM »
tanner0441 The Ryobi 40v 4 amp hour packs I've seen use the green Samsung cells. One of the completely dead packs I have is a Ryobi 40v 5 amp hour pack that is exactly the same physical size and uses exactly the same BMS but has red-brown LG cells. Removing the BMS would be nice, but I need to get a solder sucker.

A lot of times with the 20v packs the BMS simply doesn't keep the cells balanced. Manually balancing one cell at a time isn't too time consuming. I have a 3.4 to 36.5 volt variable charger for that purpose. I also have a spot welder to replace bad cells, but once one cell goes the others usually fail pretty quick. I am on my second spot welder and also get inconsistent penetration. Professional welders run on 220/240v and have much bigger capacitors inside. As it is mine makes the light flicker when I tab. The built-in battery charger also died one day, but that wasn't why I bought it.

tanner0441

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Re: Lithium tool battery repair and reuse
« Reply #6 on: May 01, 2023, 07:11:08 PM »
Hi

I use an IMax charger which has Deans plugs and sockets and JSX connectors for ther BMS, I don't put a BMS on the packs but rely on the IMax. I have so far had no problems with my packs apart from a 12V 2Ah pack I put together for a friend with cells they supplied and found they had had the BPC reset, a pin in the little holes round the positive terminal. They charged without any problems but in use they became very hot very quickly. They went rapidly out the door until they cooled down. When I gave them back I pointed out the fact they ran hot, "Oh yes thay have always done that I,ve had to reset them twice."

I just said on your head be it. Hot and 18650 cells are not a good combination.

Brian