How To Rebuild Your Old Rechargeable Battery Packs with new ones. CHEAP! 

don't tear the tab off of the battery ends, cut it in the center with tin snips to leave a tab to solder to so you are not soldering to the battery itself

i LOVE THE WAY YOU SAVED SOME MONEY BY THINKING OUTSIDE THE BOX. tHE INSTRUCTIONS WE CLEAR SO EASY TO FOLLOW. THANKS FOR SHARING YOUR KNOWLEDGE.

Great tip! Paid $10 buck for an 18 volt battery and in my case the HF battery cells fit directly in my Black and Decker pack. I just had to un-solder the wires from the HF connector and re-solder to the B&D pack. Works great.

I never knew about the ability of renewing an old 18V battery pack. I'll never have to buy an expensive battery for my Ryobi again! Very good learning tool! A+

Great video, well paced, good description without being too detailed, and without skipping over anything. Very informative, and exactly what I was looking for. Thanks Peter.

Thanks for ur helpful video. İ have no good english as much as to understand ur speaking but i watched ur video with pleasure until end. Greting from turkey.

Hi Peter. I don't care what the haters had to say. I think this video was very useful and well thought out. I like it when a person takes the time to explain every movement involved, than the lazy ones that just play music show the item move this and that not explaining a thing expecting you to know what they are doing. Wish more would do videos like you. I had stumbled on this video by accident and Glad I did. A few months back my Ryobi cordless 18V battery pack wasn't staying charged have 2 battery packs. I looked online for replacements and seen the prices and held back on getting any. This video is an answer to my problem. I like saving a dollar to. Plus I like fixing things this will be another piece of knowledge for me to put to good use and share with my friends. Keep up the Good Work Peter. You've got my Vote. and New Subscriber my friend.

This is exactly what I was looking for. Brilliant idea buying from harbor freight for a bargain price. You made an excellent video. Thanks

excellent tutorial. Thank you for posting.

Great vid, I've got an ebike that had a defective battery , among other things when I bought it from evelo. They refused to replace the bike, and continue shipping me the parts I needed to fix it, because I seemed mechanically inclined to them. I've had the battery out of the bike several times to inspect it, and realized just what you are explaining here. Now I'm sure that I have the rite idea, just save myself almost $1,000 (what they want for a new battery). Thanx bud, I'll let you know how it goes when I do the surgery. The bike was a lemon, they didn't understand what that is apparently. $3,400 for the bike new, I'll not work with them anymore, very arogent & condescending staff. You rock!

Extremely helpful. Thanks.

Surprising I haven't come across this before now, thank you so much for sharing, can save a ton of money now lol

May I suggest that in the future you use flux before you begin the soldering process. This will minimize the amount of heat required and reduce the possibility of damaging the cell from overheating. In addition it looks like you are using a soldering gun, which could be 100 or 200 watts (could not determine from the video). I would suggest you invest in a soldering iron of about 40 - 50 watts, especially if you are doing this on a regular basis. This smaller heat source and the use of solder flux will greatly reduce the chance of damage. I thought this was well done and will try this on a couple of older batteries that I have not, thankfully, recycled yet. Keep up the good videos, thank you.

i have nothing but time on my hands, very good idea. will try this for sure thanks

Thanks for the video, I enjoyed watching though I won't be trying it anytime soon, you have a good knowledge and plenty of patience young man 💖 .

Those batteries dissipate a lot of heat during soldering and you soldered them easily without flux with your giant iron. Great tip on the HF battery.

Great hack! I can't wait to try it out on my old batteries.

i refurbish dead tool batteries for a resale warehouse as one of my side gigs. i use hot glue to hold the cells together in the desired configuration. i also made darkkevind's spot welder to connect the individual cells. no worries about over heating the cells that way. i only solder to the nickel ribbon, never the batteries themselves. the welder works quite well, it is a very good design. just make sure you get pure nickel ribbon, not nickel plated steel.

Thank you for showing, now I know that I rather buy a new pack.

Good DIY stuffs. This is a great way to save some bucks. Thank you for sharing.

Interesting. I never did battery pack "Rebuilds" when I was the Guitar Doctor at Stars Guitars in San Francisco, CA., but you might want to point out for those totally unfamiliar with the difference that in electronics you use Rosin Core solder [rosin is the fluxing compound inside the solder] and not Acid Core solder [where acid is the flux inside the solder] as you would use on copper pipe for example. Yes, you always "Tin" the wire [stranded or solid core wire] first before you attempt to solder it to a connector, etc. The same with a connector you're trying to attach to a metal part - tin the connector first, not the metal battery cap. While making everything clean and neat, yes, you do need to leave just the right amount of slack. The "Heat Sink", as you call it is actually a thermal-couple of some kind if it does what you say it does. Bye the by, "Chicken Shack" [if they're still in business] sells a small pair of wire strippers for electronic applications such as this that are a whole lot easier to use one handed than the kind of monsters usually found in your typical auto-parts or big box stores. Hopefully your soldering gun has a half power setting and it seems like painter's tape could hold everything together while you try using your third elbow when soldering things together.

THANK YOU FOR SHOWING US HOW IT'S DONE ! BE SAFE ! HAVE FUN ! GOD BLESS YOU ALWAYS ! ENJOYED !

Nice and informative. I have a dustbuster that needs some love like this.

Thank you for the video. Absolutely is very good

Awesome Peter, thanks for sharing this. I will try it as soon as I can. Be careful when you are soldering with that flux core solder. The smoke is very toxic, because flux acid melts out of the inside and cleans the connection so the solder will stick. Keep up the great content.

thanks, very informative, I have 4 of those batteries and now know how to fix them.

Great video Peter. I should have searched RU-vid before I tried to use some Wire Glue from SureHold. I have tried to solder the strips to batteries in the past resulting in very poor solder connections. In watching this video, I see that your technique was to get a good spot of solder on each of the battery and the nickle strip first and then attach the two in a third step thus reducing the amount of heat applied to the battery. Found it just in time. I have a coleman drill in which one of the battery connections broke. Will be following your example to repair. Thank you very much for taking the time.

I always learn new stuff from guys like you. You may have probably saved me the expense of a new battery with this video. My problem is that I bought two cordless drills; one 1/4 " and the 2nd a 1/2". I found no use for the later and left it undisturbed in its original package in my garage. Two years down the road, I found myself needing that second drill. I put it to charge and the darn thing would not charge. I tried returning it with the original receipt and learned the supplier (I will not mention Lowes so nobody will know who am I writing about) no longer sold that brand. Somebody at my work place mentioned it could be the battery had gone spoiled for lack of use. I was almost buying a new one but chose to check RU-vid for ideas from people like you. I praise your knowledge and ask you to please keep posting your videos. Domo arigatoo gozaimas...

Great video. Very informative and quite ingenious. Thank you for your DIY project.

Your hard work is enjoyable.

Awesome presenter!!! Better than any others I've scene!!!

very instructive but I couldn't help thinking when I saw it in action you just could've got a broom lol

peter use solder flux when soldering it makes the solder flow much faster especially when working on battery"s no chance of over heating the battery. great work!!!

thank you, Peter, a very good idea, I shall attempt the procedure, as I just happen to have a harbor freight battery of the which I lost the drill, so my Dewalt drill has a dead or defective battery so game on! thank you and God bless

thanks for showing us your yard

Tip 2: when reconnecting the top cell first add solder to the button and the bottom of the connector before putting them together. All you need to do after is reheat the connector to make the solder flow together. ( by the way solder what the rest of the world uses instead of US soder) Tip 3: Don’t blow on the solder. Let it cool naturally to reduce the risk of poor joint due to “cold solder joint”. If the solder is smooth you have a good joint. If it looks crystalline, reheat till it flows smooth. Cold solder joints can cause loss in power and extra heat in the battery pack due to greater resistance through the joint. Tip 4: tape the temperature sensor to the side of one of the batteries. Any air gap changes the actual temperature measured and therefore changes the switch off time. You want to measure the battery temperature, not the air temperature within the pack. I would be interested in the mAH rating of both the old battery cell and the new. You will probably find your cheap cells are rated less than the originals.

Great information,thank you.

an old video but very valuable every time for many reasons, but the most important one is how to tweak the system thanks tho 🕵

Im sitting here looking at 5 of these batteries that are dead. I cant wait to fix them. Thank you.

Touch of miss's nail varnish on the solder joints and wires, helps to keep them connected and offers some insulation!

have found that bundle style rubber bands free from post office holds the packs well. also tinning the wires before attaching works well. i have the third hand to aid me. new cardboard cutouts was a cinch. used non conducting tape to hold heat sensor and moved that pesky wire next to connection. worked out well.

Great video! I learned some from you. Thank you for sharing.

Very helpful step by step you are a teacher

The best part of this video is finding out harbor freight sells a nicad battery pack for $12. That is so cheap and so convenient to buy locally. The cells are also somewhat vetted for quality which is way better than a random ebay seller selling cells that might be really old (at a higher price than this). Thank you

Nice video, Thank you. For future reference you may want to find yourself a 500 ferad super cap and two 12 ga. solid copper wires, (and a pack of nickel terminal strips) filed to a blunt point. Solder them to the caps' terminals and that will give you a cheap and efficient terminal spot welder. It will produce less heat and no chance of battery damage due to soldering, It works very well.Good luck👍

Tip: Cut a length of solder-wire for soldering, and use the spool as a battery holder. (Large, adjustable pliers with an elastic band is good too.)

Love the RADIO SHACK SOLDER

Thank you for the info. I saved, and subscribed. 😎

Should glue the clips to batteries to help assemble or weld easier Thank for this demo :-)

Very informative. great idea. thank you for the video, I will definitely give it a go. 👍

Great idea. And a good video! Thanks.. O the music was loud.

I gave you a thumbs up and subscribed as soon as I saw that RadioShack soldering iron... 😎

Great tutorial video

brilliant....cheers from UK

i found to hold the battery pack to together while working on it, was to put a rubber band around the pack so it dose not short out.

Thanks. When I rebuilt a battery I bought new cells and I had a hard time connecting them all together because I couldn't get things hot enough to melt the solder to get good joints. This is a much quicker way to go.

Great video, I'm gonna give this a try. Thank you!

Great!’ I’ve got a couple of Dewalt 14V packs that are long gone and the drill still good. Costs $94. per battery to replace.

Hello ! Have you ever heard about FLUX ? FLUX is your best friend if your soldering components ! Makes it easier soldering ! And clean your soldering iron tip and do solder on it so you can better solder and protect your solder iron tip ! Best regards, thank you for your informative video !

coupla pointer on soldering to the battery itself ; 1. ALWAYS tin the battery after sanding a bit or using a small file to knock those pointy leftovers on it after you tear the flat ribbon jumper off it , also sand /file the ribbon and tin first , then when you apply heat they'll just join quickly with a bit more solder 2. forget that big stupid high wattage solder gun thats guaranteed to overheat the battery and get a quality 60 watt iron(pencil) , you'll thank me for it , controlled heat that stays on , so youre not dickin around waitin for it to get hot every time .

Useful Video, It could be worth taping the batteries together for stability while working with them, also to tape thermistor to the pack before reinstalling.

Interesting video. A little clumsy handling at times. Job well done.

Great video!

Great instructions

as a wood butcher I chose Ryobi early on and now have 10+ dead batteries. I can never catch them on sale and they are $40 each here. Am going to get this done ASAP. Thank you for walking me through this. do you save the old batteries for franken-pack or just new set up?

One thing you did not mention, was that the HF battery does not have POWER of the original battery. You can tell by the weight - the HF one is A LOT lighter than the original. The original actually feels HEAVY. This means it won't last as long on what ever job you are doing. But, I like it! and will use it on a couple of Craftsman batteries I have laying around. I do have a bit of a complaint, while do a good job of your step by step, it is too long - you could cut a lot of your redundant verbiage. All in all, you did a good job of it, and gave me a good idea. COMPLETELY agree with Lei below. tnx

Really good video. Thank you.

Helpful video. I would suggest removing any metal watches or rings whilst handling battery packs as you could end up with a severely damaged wrist of fingers.

Good video and Thanks for sharing .

how to rebuid your old rechargeable good job

Thank you! Sadly I can't find those ultra cheap 18V batteries here in Germany, but what I can find are 18V 3,5Ah 20€ Bosch replacement packs. I will use the cells to rebuild my pretty rare (~75 for replacements) Hilti battery pack. Thats actually a great deal because single NiMH (or NiCd) Sub-C cells are pretty expensive at around 3€ per cell. that would make 39€ worth of cells for just one 13 cell (15,6V) pack

Thank you for this very informative video! I do have one question; can you comment on the overall capacity of these Harbor Freight batteries as compared to (for example) the original DeWalts? If I understand what I'm reading on the internet, the DeWalts are in the range of 3,000 or 4,000 or 5,000mAh while the Harbor Freight seems to say it is 1,300 mAh. SO, if this is accurate, your rebuild would be of much lower capacity. Am I reading all that correctly, or is the comparison apples vs oranges?

It's a good thing you didn't mix cells from both packs together, the Robi's could be 1Ah, 2Ah or 3Ah vs HF 1.3Ah. There are "Ryobi replacement packs" for the P100 One+ (not Ryobi), 2 for $32 vs the $13 HF battery pack. That's nearly 3x the Ah for $3 more, or you can get a single P100 3600mAh "Ryobi replacement pack" for $19. No fuss not muss. Even buying 15 sub-C batteries online would offer better value than the HF $13 pack these days. You have the flexibility to create a pack with the number of Ahs you prefer. The more Ah per pack means the longer you can run that tool without recharging. 1Ah means you can expand 1 amp per hr before you have to recharge, 3Ah means you can expand 1Ah for 3 hours, etc. How long you can run a particular tool depends on how much energy that tool requires to operate. If it uses 1Ah/hr, then you can run that tool for one hr, but with a 3Ah battery, you could run the same tool for 3 hours.

I got a question.. i got 4 battery packs, all are Ni-cd, wondering if i can connect them 3 battery packs are 4.8v(4 AAbatteries per pack) and the another 1 is 6v(5 AA batteries) Would it be safe if i unsolder them and create a custom batter pack? For example, taking the 5AA batteries and connect it to the 4AA battery pack, is it safe to use? I tries it bur after connecting to an rc vehicle, the motor starts smoking, am not sure if it will explode because i took the battery right away.. not sure if i did the connection of the 2 battery packs correct..

I know you are very competent at soldering battery packs, but to keep the heat off the new cells. Would it be of help to pre tin the connections or are you concerned about too much flux floating around? What happened to the shorted out cells? Dave M

Regarding soldering and or spot welding the cells. A spot welder can do damage and so can a soldering gun. The spot welder can make punctures. The soldering gun has a skinny tip which has only a small amount of thermal inertia. When you apply the tip to the work the heat is almost instantly drained away and you have to hold it there while the tip and work heat up. This can cause internal battery damage. I suggest using a small 40 watt soldering iron with a big tip. The tip has a lot of thermal inertia so won't cool down too quickly as you apply heat to the cell. The outside of the cell and the steel conductive tape heat up fast enough that the cell contents get very little if any damage. I use the same strategy when installing RF connectors to coax cable for my ham radio work. What a difference. I used to use a gun and it would heat and melt the inside plastic separators in the RF connectors. All the best fellow do-it-yourselfers.

amazing congrats!!!

Excellent.

Always remember to use a small heat sink alligator clip between the battery terminal clip and the end of the wire you are soldering so it can wick the heat away from the battery to keep from over heating the cell...

It looks like you didn't solder directly to the cell, it was to nickle strip and a button-top. To solder directly to the cell, one might want to use flux and cooling sponge. The high temperature iron is good apparently because while the surface gets hot very fast, it does not conduct inwards as quickly. DiodeGoneWild and MrCarlsonsLab have videos on soldering directly to cells. Made more recently though, and this does show you what's in the Ryobi pack! Thanks for the video!

What kind & size welder did you use & what was it set at

Good Video, You Can Also Pull Your old Batteries Apart and Keep The Good Cells - Take some Pictures Of How They Were Originally Joined and Join The Good Cells Together To Make a New ( ISH ) Battery

This is Child's Play hit me up when you get the LiPO batteries

Very cool idea!

How about using some tape, or a thick rubber band to hold the pack together while you're working in it?

Good video and some good points have been made below about using flux to reduce the chance of heat damage. Also, make sure not to toss your old battery packs into the trash as all rechargeable battery packs recycle. If you toss them into the trash they can cause a fire if they short out. Place them into a plastic sandwich bag and give them to a recycling center (most electronics store will take them).

Hi Peter. Very informative. If you see this question: What wattage of that classic RADIO SHACK soldering iron did you use for this soldering of the battery cells? thanks

Nice video. like the old radio shack gun and solider. can not get them anymore.

Do be careful. NiCd cells can go into thermal runaway just like lithium can. It takes a worse mistake to cause it, but they also take longer to self destruct, meaning the fire hazard lasts longer. NiCd batteries can withstand a TON of abuse and they don't care if it's really hot or really cold. Shocking them repeatedly can cause this! Also, *both* of your batteries needs attention. The charged pack should register 19-22 volts. How shocking works is to melt off parts of the crystals that form in the NiCd cells. This also damages the separators, never mind that the crystals do that and they're conductive to begin with. Damaged separators = energy drain or short circuits. Also be *very* sure the cell chemistry matches. Charging methodsa and discharge characteristics are very different with each chemistry. I ran into this with a set of Black and Decker tools when I built battery adapters for some Craftsman V20 batteries. The tools don't shut down automatically for low voltage but I know when to stop. I've done this same mod many times and found better luck just building adapters and running modern batteries. Every time I rebuild a pack, though, it spends the night in a fireproof container.

Always good to make do and mend. Your soldering technique needs a little improvement though. Never ever blow on a hot solder joint,,,,, always let it cure at its own speed. This can cause cracked or dry joints. Might be worth investing in a small spot welder for better current transfer on those bridges.👍🇬🇧👍

Excellent. Thank you..

Are those batteries 18650 batteries? or some other size? I have so many of these tool batteries in different brands as well, can I use them for my vape pens as well and other stuff that I might need it for? The thing is each one of those batteries at a vape shop cost like anywhere from like 10 to $15 sometimes what a rip-off but if I can take apart one of my batteries now knowing and also laptops as well have these same looking type of batteries then I can go ahead and save a lot of money lol thank you but hopefully the are the size I'm looking for if you can answer thank you sir for your video and your services

Hey Peter ! Great video , very informative , i hope when my stuff goes bad i can be able to do that too , even with my snap on products ! thanks

Nice job...GOOD WORK...THOROUGH!!! When Harbor Freight 1st sold batteries...9.6v...I TOOK ONE APART...THERE WAS A WET PAPER TOWEL IN IT TO MAKE THOSE FLAT MILD STEEL BATTERY CONNECTORS RUST...HARBOR FREIGHT SOLD HOW MANY THOUSANDS...BAD BAD BAD...MY SUGGESTION...CHECK EVERY BATTERY YOU GET FROM THEM 1st...grrrrr

Great job

Nice work

Good demo

Good job. Would it be a good idea to put a little blob of solder on the top of the battery before attaching the tab?

Thanks Peter ; NOT ALL THE CELL IN THE BATT SHOW IF IS 2000 mah or 1300 mah ,, IN THAT WHAT CASE SHOWED YOUR BATTERIES THAT? AND HOW CAN YOU KNOW IF YOU DO NOT SHOW IT?

I have several old somewhat battered Ryobi 18v power packs and thanks to thieves I am going to have to try to refurbish the ones I have left. I came across your great videos found some new batteries with a rating of 3200-3500 mah and wondered if you knew what was the maximum mah rating that the Ryobi P118 or P117 can manage? I would assume the higher mah would give me longer life in these packs. Do you know the tolerances or where I might find that information? I wanted to check before I bought a bunch of batteries and started testing them out. Your opinion is greatly appreciated. I am hoping I can use the tools I have to rebuild and get the last ounce of use out of these.