Various Flashlights And Things Get 18650ed

[rebelrider.mike]

Nice work!

Here's an extended idea for this project: if you have a TP5100, you could hook it up so that it can charge the cell, but this is secondary. By placing the TP5100 on the side of the case and allowing the usb connector to be accessed (or install a stand alone one and run wires to the board), you could essentially charge the cell and power the scope at the same time using usb power.
The TP5100 can take up to 16V (I think even 20V if I remember correctly) and can accurately drop to 1s1p for 2A charge if needed (depending on the resistor).

Altho, if you go this route, you could potentially put a lipo or cell phone battery in the case too.

I thought about that, but decided that it's easy enough to swap out the one cell, and the external cell holder is a nice way to prop it up a little.

Does anyone else think this looks like a pipe bomb?

It clearly says "water" on the side, so no. LOL!
On the other hand, every Li-Ion cell is potentially explodey, so I guess technically, you are correct. But mine has an off switch, so it's ok.

 

[rebelrider.mike]

I've been testing all these 18650 cells and using them in more and more things, but I realize I don't have a good way to charge just one cell. So I put a few parts leftover from old projects and made one.




I like to charge my cells at 500mA rather than 1A, so for a single cell I need to replace the R3 resistor with one that is 2500 Ohms. I have a bag full of little potentiometers, so I use those.

With the meters out of the way, this setup fits in a pill bottle. So I did some drilling and glueing and came up with this:




I still need to add a plug on the end, but it works. Also stands upright.

 

[rebelrider.mike]

I use axial glass fuses for fusing individual cells in my various projects. Well, the larger ones anyway. I end up with a lot of leftover leads that I clip off the fuses which I collect in a jar. Maybe that's weird, but I don't like to throw things away if they might be useful later. This time, they made great extensions for some old components that a friend of mine had stashed away and recently gifted to me.




This allowed me to put them in a little component tester I have. Turns out the big ones are capacitors, and the little one is a resistor. The bands would probably have told me that also, but I don't know how to read them. I didn't even know capacitors had bands.



(Usually the tester also gives me an ESR value, but in this case it didn't.)

This is a pretty neat gadget that identifies capacitors, diodes, resistors, inductors, and transistors. Doesn't recognise everything, but it sure is better than I am!

Anyway, you can see it's powered by a 9V battery. Well, I have several boxes of components that my friend gave me. Most of them are quite vintage looking. Over an afternoon of testing and sorting, I still have a long ways to go, and the 9V battery was getting weak. The simple thing to do would have been to track down a fresh 9V. But why do that when I can 18650 it!?





I had to make new holes in the sides of the cell holder for the wires, as the holder itself just barely fits inside the box. Oh yeah, I also decided that this time I would like the cell permanently inside the box and to charge it without taking it out. Unlike the pocket oscilloscope. Anyway, first thing to do was to remove the 9V connector.




I drilled the holes with a cordless Dremel that I haven't quite finished 18650-ing yet. I have a number of old 12V tools, and I want to make an 18650 battery that can run all of them. But it's still a half-baked idea, and I don't know exactly how I want to proceed. Maybe it will end up in a box I clip to my belt or something. Anyway, yeah, the cell holder with wires coming out the sides now:




Those leftover fuse leads I have saved up: also great for sticking a Voltage protected TP4056 board to a booster board. These little boosters are great, and I've now used them all up. I'll need to order more.




With the cell holder soldered to the TP4056 board, I can adjust the output on the booster board to just over 9V. I'm not sure what the Voltage range of this gadget is, but it's able to run on 8.8V, though the screen starts to flicker a bit. The oscilloscope sure didn't run on that little, but I think it takes more power than this tester does.



(The components at the top of the picture aren't part of the tester. They're part of that stash waiting to be identified.)

It took quite a while, but I finally got a hole filed in the acrylic to allow the USB port on the TP4056 board to stick out. Acrylic is not a forgiving plastic like polycarbonate. It is brittle, and likes to crack if you try to drill or cut it. I also had to peel off the protective coatings as the dust was just collecting between the coating and the plastic. Normally I'd leave it on except for the top. Just my personal preference.




I got the boards hot glued to the box, and soldered wires from the booster output to the 9V input on the tester board. It all fits with room to spare. (So far...)




Here it is testing a 3-pin IC of some sort. During testing, it tells you the status of the battery. In this case, 9.15V. So success!




Turns out I have an N-E-MOS. Whatever that is, LOL. Looks like a transistor with a couple diodes from the little graphic. Pretty neat, eh?




It doesn't test stuff with 4 pins or more. But that's ok. Here is the tester, now getting it's cell charged. Works great. And since it's transparent, it's easy to see the LEDs on the charger.




So one thing I forgot: I've mentioned before that I like to charge my cells at 500mA instead of the standard 1A. Especially since this is a generic Sanyo cell and I don't know its specs. I've been adding little 10K potentiometers set to 2,500 Ohms. I did this after the fact, and it turns out the potentiometer sits right in the way of the support spacer under the board. That's going to drive me nuts until I get it repositioned, LOL.



I should probably buy a bunch of 2.5k resistors. They take up a lot less room.

 

[rebelrider.mike]

A while back, I started to convert some dead 6V lantern batteries into 18650s. I got as far as getting a single one finished to use in my old red flashlight. I ran into a few problems. First, the TP4056 board I used had the protection chips on it, and it didn't want to allow a full 6V into the light bulb. (Too many Amps.) So I had to dumb it down to around 4.5V. I bought an LED bulb to replace the incandescent, but it was the wrong polarity. Finally, the boost converter was in a position that I had to make a fairly large hole to get a screwdriver in to adjust the Voltage.

Well, camping season is upon us, and I've picked up this project again. I went back and changed the polarity of the part that connects the battery to the switch and bulb, so the LED will work. This allowed me to increase the booster back to actual 6V, as the LED takes a fraction of the current that the incandescent did.



I did nothing with the adjustment hole, or the location of the booster. It's a little irritating, but it's not like I'm going to adjust it very often. Or ever.

But now with the polarity fixed, the flashlight works, and is quite bright!




With that done, I made 2 more batteries. This time with a 1s protection board and a regular TP4056 board. These will be for a fluorescent tube lantern.




Filed, drilled,and cut holes and notches for the boost board, switch, and charge controller. This time, the boost board is positioned so the adjustment screw is right by the hole.




All the cells were soldered in parallel, and connected to the BMS and other boards. The bottom and sides are wrapped in foam for a little protection, and to keep the cells snug so they don't get bumped around inside the shell.




I separated the batteries from the electronics with some styrofoam. This also fills the gap left on the top of the shell. This is something I didn't do in the original battery.




Everything was stuck in place and sealed up with hot glue. Put in series, I have the 12V needed to run the lantern.




I wondered about the TP4056 boards melting the glue, as they get hot. But it doesn't seem to be an issue. Also while gluing, I kept the actual chip and the LEDs clear of glue. A couple holes allow viewing of the charge status LEDs. And the switch cuts the boost board off from the battery. They draw phantom power even when not in use. This is more for storage. It doesn't make a difference over the course of a few days.




And it works! The whole thing takes about 0.7A at 12V, and with the capacities of the cells I used, should last over 14 hours of continuous use. We generally only use the lantern for a couple hours a day, so it's good for a week between charges. And since I didn't modify the actual lantern, in a pinch I can still use regular 6V lantern cells.




I don't know if I'll make any more, but I learn a little each time. Like next time, I might position the switch and USB port so I don't have to remove the batteries to charge or store them. Maybe I'll put the charging boards on the outside so the chip can cool better. It takes a long time to charge these guys as each battery has 9 cells in parallel, so each cell gets a maximum charge current of 111 mA. Maybe I'll use a TP5100. They are switch mode, so don't get as hot, and can output 2A of current. Or I may never build any more 6V batteries. Who knows?

 

[Korishan]

Wow, you been busy! keep up the nice projects

 

[rebelrider.mike]

This one's not 18550, but it goes along with the flashlights and lanterns.

A while ago, I can't find the thread now, I made a little tent lantern after seeing ones for $30 and thinking "I bet I could make one for free". It turned out great, but I needed a 12V battery to power it. I've had this old 3s2p pouch cell battery on my desk since almost the beginning of my battery nerdism that I used just for a quick 12V source for my weird little experiments. No fuses, or bms or physical protection of any kind, as it's just for using really quick.




Well, I started taking it along on camping trips to run the lantern (Which I made for free from an LED 1157, pill bottle, wires, and a switch) and decided it was time to make it a bit safer. I bought a bunch of 3s BMS boards, and soldered one to the battery. I also replaced the temporary barrel connector (where the screws clamp down on the wires) with a sturdy pre-made one. Way less chance of failure.




It all got packaged up in a layer of foam and duct tape.




I think my little tent lantern is heading for a version 2.0. Among the changes, I'll be putting a pre-made barrel connector on it too.

 

[rebelrider.mike]

This time, my little weatherstation is getting 18650ed.

This guy is a wireless display that has a sensor outside. The sensor has 2 NiMH AA cells that seem to last months between charges. The inside unit however, is powered by 3 NiMH cells, and seems to need charging every couple weeks or so. I've tested all the cells, and they are better than 80% of their rated capacity. Anyway, it doesn't take much to get me interested in modifying stuff, so...





Had to make sure the cells were in series, and where the positive and negative leads are.




Most AAs go from 1.5V to around 0.9V before their done, I think. Here it is running on 4.2V, and using less Amps than I can measure. Can't remember now how far down I turned the Voltage before it quit, but it should still run more or less ok on say, 3V before the screen starts getting too dim to see. Once it starts dimming, that's my que to charge the cells.




I still have lots of these 4 cell holders from an order I made over 2 years ago. I wired them in parallel, and gave them nice easy to read polarity labels.




Here it is on the wall. Normally I'd put positive up, but I messed up the orientation while I was soldering.




Runs great with just one cell that's around 3.8V. From some math I did, if I use 4 cells in parallel with decent capacity, I could get up to a year of continuous use. I want to see how long this sell will last first though.

And I didn't even need a Voltage regulator!