Retrofitting old electronics to Lithium Ion Power

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Sclass
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Retrofitting old electronics to Lithium Ion Power

Post by Sclass »

Ego inspired me to share this (again).

I've mentioned in the past that I like to refurb old electronic devices that use rechargeable batteries. Don't you hate throwing away something that needs a proprietary Nickel Metal Hydride battery from the manufacturer that exceeds the replacement cost of a new unit? Here is an example.

Futaba airplane radio from the 80s. Used nicad batteries that died and leaked long ago. The replacement pack costs a fortune because it's made by cottage industries that exist to keep vintage RC stuff going.

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I'm not a purist so I don't care if it isn't original Futaba anymore. I just want to control some robotics projects with the radio. So this is what I do. Three Li cells approximately match the voltage of the umpteen nicads it used to have.

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I go to ebay and buy one of these 18650 Li Ion battery clips. Its like a AA holder but bigger. Costs $1. Double stick tape it to the back of the radio. Solder +/- wires between the radio and the battery clip.

I salvage some 18650 batteries from old laptops. But you can also buy them for less than $2 each. Once you use these, you'll wonder why everything AA powered isn't designed with 18650. AA should be made illegal. 18650 will hold 75% of their charge for over a year on the shelf. The number of recharge cycles they take puts nicad to shame. They also have a high energy density and can source a lot of current. Junk batteries can be found in all kinds of stuff. Just start tearing stuff up. Kindles have nice batteries too. You just have to unwrap them and solder wires to the cells. (use common sense, shorted cells can blow like a Samsung phone!)

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Motorola spirit walkie talkies for when the cell grid goes out. Useful where there is little cell reception. The proprietary motorola battery is crazy expensive and it dies after a year of use. So I do the same old trick.

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Here's a toy car that I converted to laptop batteries. See the white pigtail in the front of the battery pack? That's the charge cable. You can buy those pigtails by the dozen on ebay for dimes. It's a standard balance connection used by RC car people and connects to standard cheap chargers.

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Getting the idea?

How about charging? Ebay again. Lotsa different kinds of LI Ion chargers out there.

These: (good for simplicity) $2
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These: (good for multi cell balancing) $2
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These: (common for model helicopters) $2
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They even sell these high power LED flashlights that use recycled laptop cells. I've fully converted at my home. No more AA battery lights. Those should be made illegal. This brown flashlight only costs $5 shipped. Blinding brightness and a two hour burn time on free batteries.

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This is a neat freebee given to me at a tradeshow recently. It is a LI battery in a little box with a USB input and output to act as an onboard charger and power supply for a phone. So you can charge this on a PC then use the power to power up a bike light for example. These chinese wonders are dang near free online. So you can make your own rechargeable devices with one of these and a scrap of old USB cable.

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Next time you trash a dead iphone remember that there is a nice battery still in there. Strip all your ewaste. Don't give it to some third world sweat shop. Cherry pick it first.

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Have fun. And be careful. Charging LI batteries incorrectly can start fires. Shorting LI batteries can cause explosions. The batteries contain Li and an extremely flammable electrolyte = Molotov cocktail the size of a grenade. Do your Youtube research first if you are uninitiated. Watch what happens when you poke a pin through the electrode. I like to charge the batteries in a metal ammo can to contain a spontaneous explosion. (It's actually scary we do this same thing with our phones regularly without a thought). With great power comes great responsibility.

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Ego
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Re: Retrofitting old electronics to Lithium Ion Power

Post by Ego »

This is exactly the kind of advice I love to get!!!

It is easy.
You can do it.
No problem.
Look at this....
Oh, by the way.... it can become a bomb if you do it wrong.... so be careful.

I love it! I am now on the lookout for my first project.

vexed87
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Re: Retrofitting old electronics to Lithium Ion Power

Post by vexed87 »

I think we're getting too advance for my n00b skilz, but how could I get two new and unused iphone batteries in series to charge other gadgets? Is this a big project for a newbie? :)

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Re: Retrofitting old electronics to Lithium Ion Power

Post by jacob »

Suggest considering rewiring gadgets to run directly from mains when mobility is not needed. Batteries are inherently wasteful. I'm thinking, for example, a cell-phone that plugs into a wall outlet.

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Re: Retrofitting old electronics to Lithium Ion Power

Post by Ego »

jacob wrote:I'm thinking, for example, a cell-phone that plugs into a wall outlet.
:lol: Oh man, you are asking for it. When they interview you for Time Magazine's 100 most influential people, they'll love this one.

Maybe you could get one of these to go with it.

Image

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Re: Retrofitting old electronics to Lithium Ion Power

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vexed87 wrote:I think we're getting too advance for my n00b skilz, but how could I get two new and unused iphone batteries in series to charge other gadgets? Is this a big project for a newbie? :)
Hi,

Not sure what you're asking. iPhone batteries like the one I show are 3.7v. You need double or triple that voltage?

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Re: Retrofitting old electronics to Lithium Ion Power

Post by vexed87 »

Oh wait, I meant put them in parallel to up the battery capacity, not the voltage, definitely a newbie at electronics!

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Re: Retrofitting old electronics to Lithium Ion Power

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Ok. You can certainly wire the cells in series or parallel. Check for your +&- connections with a voltmeter. If you are unsure how to do this, practice with some AAA batteries first.

As I said before, these batteries need to be respected. Google "e cigarette explodes" images and find out why. This is what happens when you draw too many electrons in too short a time. Do a little youtubing.

Anything good has an element of risk. Make sure you know what you're doing before kludging up LI batteries.

If you just want to up capacity, use the USB power stick shown in the second to last photo in the OP.

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Re: Retrofitting old electronics to Lithium Ion Power

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Here is a retrofit I did today. Not sure if it was worth it. Several hours of 3D printing and a lot of fidgeting getting it together. I have a bunch of these free harbor freight tools flashlights lying around. I burn through their batteries and I started feeling guilty about it. I have a lot of 18650 Li Ion batteries around. I had an old pal who worked in IT and he gave me tons of dead battery packs. I learned how to rescue the good cells out of them and made a mountain of batteries that I use for mostly flashlights and some other retrofits shown in this thread.

I found this Thing on Thingiverse. It is a couple of frames that hold a 18650 cell in a harbor freight lamp. It also holds a TP4056 USB li ion charging board. These are a super cheap (sub $1) li ion battery charger on a postage stamp board. It's powered by USB micro.

https://www.thingiverse.com/thing:5020393

This is kind of a trash can light. I'm not sure if it was worth the work. But i feel guilty trashing it after the batteries go dead. Now it'll probably last longer than I need it. The nice thing is somebody else designed the 3D model so all you have to do is hit print. The electronics is cheap and also already designed for you. The battery is free. It only costs time which is mostly assembly.

The process is pretty simple. Print out the frames. Put the little board and battery in and connect the charge module, battery and LED board together with four wires. I used some scraps I had lying around from another piece of junk I gutted. This is a nice proof of concept and it saves the landfill from another piece of junk. I think this technique is best suited for good items that are in need of an updated battery. Like an old radio, test instrument or a higher end flashlight. I redeemed too many free flashlight coupons.


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batteries. comparison of cheap cells and 18650. I think I'll recycle the batteries for their zinc electrodes. They're good for electroplating rusty bolts.

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The teardown. New parts in the middle ready to load boards.

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The TP4056 module. Cheap easy way to put charging capability into a device. No external charge cradle required. Connected with junk wires salvaged from an old wiring harness. They're too thick BTW. It would have been easier to use finer stuff but this is what first came out of the junk box.

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Testing before I put it all back together. You want to make sure this works before assembling. Assembly is tough because the wire routing is dense inside. The screws are fidgety because it uses mostly recycled screws from the old light.

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New VS. old. You get a bit of a bump but the light stands up a bit better on the bench.

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Charging. You can see a little glow of the status light through the housing.

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Gilberto de Piento
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Re: Retrofitting old electronics to Lithium Ion Power

Post by Gilberto de Piento »

What is your method for rescuing the good cells?

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Re: Retrofitting old electronics to Lithium Ion Power

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Oh, just a voltmeter. The bad one will be the lowest voltage.

So there is a battery management system in he packs. It measures the individual cell voltages for all the cells. When one drops out it shuts down and won’t drop into the charging routine anymore. This is the dreaded flashing yellow or Orange light on your Laptop when your battery is “dead”.

On every pack I’ve taken apart it is always one bad cell. One is close to zero volts and the others are fine or low, like 2.5V.

I tear away the little tabs with pliers (don’t cut yourself) and peen down the sharp points with a little block of wood. Then the good cells go into a charger. Sometimes the cell needs to be jumped on a power supply to get he voltage up to where the charger will agree to charge it.

It has been a long time since I’ve seen a laptop with 18650 cells. Good PCs have moved to flatter packs. That was something from the last decade. My friend gave me a big box of the batteries in 2015. I tore them apart and salvaged a big pile of cells.

There are YouTube videos on salvaging these cells. You can find them in old Dyson packs, tool batteries. Portable industrial/medical equipment. Alarm backups. Kids toys. Portable Bluetooth speakers. If I find anything electronic in the trash I tear it down. It may contain a battery pack among many other useful things like, wire, screws, populated boards etc.

People are looking for that stuff now. Just saying if you are tossing a Dyson pack or an old laptop pack, tear it apart.

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Re: Retrofitting old electronics to Lithium Ion Power

Post by Gilberto de Piento »

Sclass wrote:
Mon Jun 06, 2022 5:39 pm
Oh, just a voltmeter. The bad one will be the lowest voltage.
20 years ago I would tear down RC car nicad batteries into individual AA cells and use them to power things, mostly RC car radios as shown in your original post and flashlights.

I still have some RC cars from the 7.2v nicad era like what you showed in your post. I've recently become interested in getting them going again but I only plan to run them a couple times per year. One or two runs would probably be enough and I don't need top performance. It looks like in your original post you have done this already. The old electronic speed controls my cars have could run on 7.2v (6 cell) or 8.4v batteries (7 cell), though I always used 7.2v. They will run even if the voltage gets very low. I'm not interested in buying a new battery and charger for something I'm going to use a few times and then having the battery be useless in a few years. Too wasteful for me.

I have a bad 10 year old laptop battery that I'm guessing by the shape has 6 18650 cells. I'm going to pull it apart when I get a chance. Will I need a charger for 18650 individual cells to try to charge the cells to find out if they are usable or can I just measure voltage without trying to charge them?

It looks in the picture like you have 3 or more cells in the car battery. Since the cells are 3.7v it seems like a pair of them will give the necessary voltage. Can you give more detail about how your battery is set up? 6 cells in pairs so it gives 7.2v? The easiest and most convenient would be if one of the spring loaded holders would work but I think they would likely melt given the draw from an RC car. Are any additional electronics/battery management needed in the car battery? How do you charge it?

I'd really like to make an ebike battery like this since they are very expensive but the voltages / potential for fire is scary.

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Re: Retrofitting old electronics to Lithium Ion Power

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Gilberto de Piento wrote:
Tue Jun 07, 2022 9:30 am
Will I need a charger for 18650 individual cells to try to charge the cells to find out if they are usable or can I just measure voltage without trying to charge them?

Can you give more detail about how your battery is set up? 6 cells in pairs so it gives 7.2v?

Are any additional electronics/battery management needed in the car battery? How do you charge it?

I'd really like to make an ebike battery like this since they are very expensive but the voltages / potential for fire is scary.
To jump an 18650 I just use a 12v power supply. I connect it for a minute. It draws 500mA. Get the battery up to 3v and if it holds the charge put it on a Li charger to top it up. Or, you can buy a multi tap balance charger like the black box above with the red white and blue label. It individually charges up to three cells even when they’re connected in series to exactly 4 V. Hence the name - balance charger.

I think I did 3s2p for that car. I’ll need to check. The voltages aren’t perfect but they’re close enough.

I do not have a management system. I just drive around till the car gets slow. Then I charge. My serious RC buddies cringe when I do this and say I should put a shutdown circuit (available on eBay) in the car or at least a voltage monitor which beeps when I get low voltage. But I don’t drive that much.

I got this car off a friend. We played it as children in the 70s. He was my rich cousin. He was tossing it during a move and he gave it to me. I retrofitted it and he screamed it was dangerous. I did it anyway. Just for fun. We relive our youth driving it around in my livingroom over beers and pizza.

ETA. Battery is 3p2s. You can see the three pin balance plug

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Re: Retrofitting old electronics to Lithium Ion Power

Post by Gilberto de Piento »

Thanks for all the info. I had read up on the 3p2s thing. Cells both in series and parallel was new to me. I'm still trying to understand it. :)

I will let you know what I come up with if I take apart the pack I've got.

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Re: Retrofitting old electronics to Lithium Ion Power

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I did 3p2s because the 18650 batteries don’t source enough current. Putting three in parallel triples the current like dumping three buckets of water simultaneously into one funnel. Like three tributary streams merging into one. Backing them up in series increases the pressure to get to the 7.2V. Individual cells are 3.7V. You want both current and voltage for those little cars to give you cranking torque and top speed. I think I tried 1p2s and it just went too slow.

Also the spring clip battery holders didn’t work well in the cars. The connections weren’t robust enough for the high currents and the car went slow. To connect the batteries I used pennies soldered between the terminals. That’s pretty unorthodox but it’s a cheap way to gang neighboring cells together in a pack.

Also all 18650s aren’t created equal. I have a big pile and certain manufacturers like Samsung and certain cell variants INR18650-15L for example seemed to have better burst performance. Laptop batteries aren’t optimized for RC car performance so I had to pick and choose specific cells from my collection for best results.

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Re: Retrofitting old electronics to Lithium Ion Power

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I retrofitted the little $27 oscilloscope I bought to use an old Li ion phone battery. You can buy a battery powered option for $3 as an add on. I should have done this. I had the old candy bar phone and a battery and I wanted to use it. The idea was I'd just solder in a battery and use the USB C plug to charge it. Turns out they left out the charging circuitry to save money on the batteryless option. So I had to wire in a TP4056 board to convert usb voltage to Li ion charge voltage and then pipe that into the oscilloscope's mother board. Kind of a pain. Kind of unnecessary but I'd already bought the oscilloscope from China and there really isn't any returning it for another at the cost.

So here is the retrofit. Took a bit of time to figure out where to hack my new power source into the oscilloscope but I figured it out. Works well now. It's a portable digitizing scope for $27. Really cool. The portable battery really is great. I'll be able to carry this with me on customer tech support calls. Easier than packing a full sized scope.

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Re: Retrofitting old electronics to Lithium Ion Power

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I've got a good one today. This is almost qualified to be a something for nothing.

I was walking in the nature area next to my home this morning and I was stunned to find all this trash in the stream and gullies. Little single serving drink bottles. Boxes from vape devices. I stumbled across this thing sitting in the mud. It's a one time use vape device made to look like a kids toy. Stunk like cheap strawberry candy. At first I was thinking WTF is this world coming to. Then I came to my senses. I had something valuable in my hand.

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I picked it up and started tearing it apart on the trail. I dumped most of it in the trash but I kept the interesting bits. A lithium ion battery and a USB C port with a lithium ion charge controller. I got home and wondered if the battery would take a charge. It did. Unbelievable. All this good material in this device and it is a one time vaping device. Tossed into a gully after it likely ran out of juice.

Contained this tiny USB battery charger with a USB C port on it.

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This 650mAH battery. This is about half the capacity of an AA. It can source more current than an AA alkaline to heat the vaporizer.

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So I took all the stuff and hot glued it into this LED lantern I own. It had gone dead because it runs on AA alkaline cells. I got sick of reloading it with new batteries and tossed it on the shelf. After changing batteries twice I realized it was a junk purchase but I didn't have the heart to toss it given I'd paid $5 for it. I figured if I made it rechargeable I'd be more likely to use it. The Li cell has half the mAH but I suspect it can run longer at high current than the AA alkaline. On the old AA batteries the lantern just got dim after only twenty minutes. Anyway, it was free so I decided to dump it all into the old lantern. Seems to work well. A little solder, junk wire salvaged from the vape and some dots of hot glue.

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Charges with a USB c cable like this.

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Drilled a little access hole under the screw down battery cover. This makes a handy charge port.

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Done deal!

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Re: Retrofitting old electronics to Lithium Ion Power

Post by rref »

@Sclass: Nice! The included USB C charge controller seems so wasteful for an apparently non-reusable product. Unfortunately they can be found as trash in Europe as well:

Scavenging rechargeable lithium cells from the roadside
More free street-lithium reclamation

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Re: Retrofitting old electronics to Lithium Ion Power

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Thanks for the vids. The unit I found was not refillable. I’m sure you could refill it if you were determined to do it. I believe the charging port is there because the battery capacity isn’t high enough to use up all of the installed liquid. So you recharge electricity and you use it till the liquid is consumed. I got the liquid all over my fingers and it took a day to wash the smell off. The lantern now stinks of fake candy.

That’s how I think it works. I don’t know how to vape. The ones in the video are even worse. They have a rechargeable LI ion battery but no way to charge it!

This is just so wrong. :x It makes me embarrassed that some engineer designed this trash. A perfect example of people getting rewarded for doing the wrong thing. Our feedback loop is set up to damn the human race. The batteries are rechargeable and they’re just ending up in the gutter! The dumb wrappers are all over the hiking trail. It’s so short sighted.

At least make a nice durable device that can be refilled, recharged and eventually rebuilt for years of inexpensive vaping. Although I’m not into vaping I do appreciate the Mod style of vapes that are infinitely rebuildable and customizable.

I don’t even know why these things are available. I thought JUL got banned for making bright colored vape toys filled with candy flavored nicotine salts. Something is just wrong out there.

ETA - OMG it’s regulation gone wrong. This is dumber than dumb.

https://www.nytimes.com/2020/01/31/heal ... sable.html

https://www.npr.org/sections/health-sho ... -vape-pens

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