I have two bad Ryobi battery packs. I would really rather not just toss em, thats not good for anyone.
The digging I have done says that its possible, but can be tricky. Im not sure if thats general "this is the internet, be careful cause I dont know if you are an idiot." or if its genuinely tricky.
Of concern is also that a former boss' garage burnt down due to refurbed batteries. I would be unhappy if that happened.
So, anyone worked on their battery packs? Success stories? Failures?
Mr_Asa said:Of concern is also that a former boss' garage burnt down due to refurbed batteries. I would be unhappy if that happened.
To me, this is the big question: "Is the risk worth the reward/money saved?" When it comes to this situation, IMHO, that answer is "No." ...so I would just buy new batteries. Or in the case of Ryobi - I'd look for a tool I don't have but want and includes a couple of batteries in the kit.
I haven't looked in a while, but I seem to remember all of the "home center" stores have battery recycling bins near the entrance.
Question: what are the symptoms that they are bad? Will they not take a charge or are they not holding their charge for long enough? If it's the first one, I learned a trick where you manually apply a few volts DC to the battery for just a few seconds then throw it on a charger and it'll charge right up. I had a black and decker battery that sat for too long and went below the chargers happy voltage so the charger refused to charge it. I connected 9vdc (in my case using an adjustable bench power supply but I've seen people using 9 volt batteries) positive to positive, negative to negative. Wait literally ten seconds then throw it on the charger. It seems to juice the packs voltage just enough to get the charger happy to charge it.
now if it's the second and the batteries just aren't lasting long enough that's gonna need new cells and I haven't tried that on a power tool battery.
In reply to dculberson :
That worked with NiCad, does it still with Li-ion?
dculberson said:Question: what are the symptoms that they are bad? Will they not take a charge or are they not holding their charge for long enough? If it's the first one, I learned a trick where you manually apply a few volts DC to the battery for just a few seconds then throw it on a charger and it'll charge right up. I had a black and decker battery that sat for too long and went below the chargers happy voltage so the charger refused to charge it. I connected 9vdc (in my case using an adjustable bench power supply but I've seen people using 9 volt batteries) positive to positive, negative to negative. Wait literally ten seconds then throw it on the charger. It seems to juice the packs voltage just enough to get the charger happy to charge it.
now if it's the second and the batteries just aren't lasting long enough that's gonna need new cells and I haven't tried that on a power tool battery.
You need to start learning how and why packs fail and catch fire before you start rebuilding packs, in my opinion.
Most packs have a protection board/circuit which locks out the batteries if they go below a certain voltage. Adding a bit of power back in a non-standard way bypasses these circuits and lets you "revive" a battery. The issue is why these circuits exist: when li cells are over drained or over charged or over temp it changes the physical properties of the battery. These changes can lead to catastrophic or minor failures. Some batteries are robust, and you can bring them "Back to life" with only minor probably not noticeable damage/loss of capacity. Some batteries are not as robust and or the physical changes may be more severe and you could get into failure modes, one of which is the mentioned fires.
Some tool batteries have the protection circuits in the batteries, some have them in the tool. Some batteries balance cells, some don't. Again, you should start learning then decide if you feel you can mitigate the risks and are comfortable.
One of the best sites with various articles on Li battery mods is hackaday blog. Link , Safety , chemistry There are countless youtube tutorials on how to physically disassemble but its up to you to determine if the technique is risky. Shorting out a cell when opening packs is very dangerous.
Once you decide if you want to keep going you can purchase a battery tab welder for little or lots of money, or you could attempt to solder without introducing damaging heat. Most li cells on amazon are poor quality and do not output as advertised, but they are very inexpensive! A reputable dealer will have quality cells and you could upgrade the capacity while your in there.
Battery bike guys seem to mod battery packs so you can learn some info from them. This youtube channel gets into some custom packs but isn't quite a "diy how to" battery test
All this said: I have metal surplus .50 call ammo can I store my "custom" batteries in and keep the box isolated from flammable stuff. If my batteries cook off theoretically the damage will be isolated.
have fun learning!
As a tag-along to this thread:
I'm heavily invested in the DeWalt ecosystem. However, over the years I've had a few batteries go bad and refuse to take a charge. Does anyone here repair batteries or know someone who does? Is repairing batteries more cost-effective than buying new?
Yes. A ton of them. Especially Ryobi (and DeWalt).
if you are comfortable with a multimeter, you can do it. You will need an adjustable CC/CV power supply, like this. If you want to do higher voltage packs like for yard tools or golf carts get the higher voltage one.
when I get back to the computer I'll post some links. If you really have a dead pack as opposed to just unbalanced cells, you want an internal resistance 4-wire tester and spot welder to make repairs.
Ryobi and dewalt are easy, you can safely fix them if you pay a little attention to electronic safety.
RevRico said:In reply to dculberson :
That worked with NiCad, does it still with Li-ion?
Yup, did it with my B&D 20v li-ion for my backpack sprayer last season. I accidentally left the battery on the sprayer switched on and it dropped the voltage so low it wouldn't charge. A quick tickle with the bench charger then onto the regular charger and it worked great - and still works!
In reply to bbbbRASS :
I'm definitely fine with a multimeter. I have either 3 or 4 dead DeWalt 60V 6Ah and 9Ah batteries that I'd love to resurrect; those things are expensive!
I wouldn't be afraid to test and replace cells, as long as you don't bypass the battery management board etc there shouldn't be any increase to fire risk. Another tool you might need is a spot welder, they could be had cheaply from AliExpress at least a few months ago...
Most of the time, if the battery tests at full voltage, works as expected but dies quicky the issue is actually going to be charge imbalances. One cell pack in the series will be discharged or overcharged relative to the rest. (Although continued use in this state can damage cells.)
What I do is use a 12v incandescent bulb to discharge each bank until they're all within 0.01v. (Alligator clips on the respective banks attached to a bulb socket) Then charge the pack, let them sit overnight recheck. Will do more balancing if needed or put them back in rotation.
It's very time consuming, and something I only do when I'm in the shop. If I leave for any reason (restroom, coffee etc) I unhook everything so when I get distracted I don't screw up anything.
If you want to get into rebuilding packs you'll need to learn how to balance them anyway. Typically you'd use an automated battery balancer, but that's a bit higher risk if you screw up. Eventually I'll jump into that, but for now, the 12v bulb method was free and relatively hard to turn catastrophic.
I just "fixed" 3 Ryobi lithium packs that wouldn't charge.
Apparently they can get too dead for the charger to recognise them
I opened the packs, used a multimeter to determine polarity on each cell, then used a bench power supply to briefly (like 30 seconds each) charge each cell individually. When they all read some voltage with a multimeter, I closed them up and put them back in the charger.
All three are working fine now.
Sure beats buying new batteries.
In reply to brandonsmash :
I'm going to make a repair thread. Are those Flexvolt? I have both the 6&9Ah flex, but wasn't sure if there is a straight 60V version. The flexvolt are harder to repair, but I got my 9Ah from the recycling bin and made it work again.
In reply to ShawnG :
Yep, the Ryobi are notorious for this because of their battery circuit board.
In reply to bbbbRASS :
Please do a repair thread! All Dewalt 60V batteries are Flexvolt. The pinouts for 60 and 20v are different but the FV batteries are compatible with both (but 20V batteries will obviously not fit in 60V tools).
I'd have to check, but I think these don't register properly (or they immediately show as full) on a charger. It's not that they discharge quickly, it's that they don't charge.
In reply to brandonsmash :
If they show full right away that can still be an imbalance. One cell is discharged and another (or several) banks are overcharged so the charger still sees full voltage, but the battery protection circuit kicks on seeing that low bank.
In reply to Crackers (Forum Supporter) :
Timely!
I have one now that shows on the charger as being charged, but on the battery only shows two of five bars. I was able to get it to charge to five bars by letting it sit overnight, installing the battery on the unplugged charger then plugging it in. It charged, now shows as being fully charged, measures, and works as it's fully charged. What's going on here?
Ryobi guy here , Home Depot often has sales of a tool , battery and charger for $60-$75,
And the have Ryobi day sale in the summer with some great deals ,
You can also use the older 18V Blue Ryobi tools with the current batteries , and you can often buy the "Blue" tools for a few dollars each at swap meets / yard sales etc
daytonaer said:dculberson said:Question: what are the symptoms that they are bad? Will they not take a charge or are they not holding their charge for long enough? If it's the first one, I learned a trick where you manually apply a few volts DC to the battery for just a few seconds then throw it on a charger and it'll charge right up. I had a black and decker battery that sat for too long and went below the chargers happy voltage so the charger refused to charge it. I connected 9vdc (in my case using an adjustable bench power supply but I've seen people using 9 volt batteries) positive to positive, negative to negative. Wait literally ten seconds then throw it on the charger. It seems to juice the packs voltage just enough to get the charger happy to charge it.
now if it's the second and the batteries just aren't lasting long enough that's gonna need new cells and I haven't tried that on a power tool battery.
You need to start learning how and why packs fail and catch fire before you start rebuilding packs, in my opinion.
Most packs have a protection board/circuit which locks out the batteries if they go below a certain voltage. Adding a bit of power back in a non-standard way bypasses these circuits and lets you "revive" a battery. The issue is why these circuits exist: when li cells are over drained or over charged or over temp it changes the physical properties of the battery. These changes can lead to catastrophic or minor failures. Some batteries are robust, and you can bring them "Back to life" with only minor probably not noticeable damage/loss of capacity. Some batteries are not as robust and or the physical changes may be more severe and you could get into failure modes, one of which is the mentioned fires.
Some tool batteries have the protection circuits in the batteries, some have them in the tool. Some batteries balance cells, some don't. Again, you should start learning then decide if you feel you can mitigate the risks and are comfortable.
One of the best sites with various articles on Li battery mods is hackaday blog. Link , Safety , chemistry There are countless youtube tutorials on how to physically disassemble but its up to you to determine if the technique is risky. Shorting out a cell when opening packs is very dangerous.
Once you decide if you want to keep going you can purchase a battery tab welder for little or lots of money, or you could attempt to solder without introducing damaging heat. Most li cells on amazon are poor quality and do not output as advertised, but they are very inexpensive! A reputable dealer will have quality cells and you could upgrade the capacity while your in there.
Battery bike guys seem to mod battery packs so you can learn some info from them. This youtube channel gets into some custom packs but isn't quite a "diy how to" battery test
All this said: I have metal surplus .50 call ammo can I store my "custom" batteries in and keep the box isolated from flammable stuff. If my batteries cook off theoretically the damage will be isolated.
have fun learning!
This is the only sane answer in this thread. Do not mess with multi-cell Li-ion batteries unless you are comfortable with this workflow.
Alternatively, Ryobi will just give you new batteries if they are less than 3 years old if you contact customer support. Otherwise take them back to Home Depot and just play dumb. Home Depot doesn't care they just send the batteries back to their prospective brands and they generally get lost or stolen by the workers in the distribution centers.
In reply to RacetruckRon :
I started the repair thread. I will second that you can often get a warranty replacement pretty easily.
Yes you need to be safe fixing batteries, but if you work with gasoline you know how to be safe enough.
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