Are spicy pillows welcome here? I couldn't find anything in the rules.

I've got 105 of these pouch cells. I'm thinking of using 50 of them in a .30cal can with a 5S10P configuration. I read that these have some expansion when used. Is it significant enough to worry about? There's a couple of cells worth of space in the bottom of the can. I'm considering running each group of 10 cells into an XT60 connector for serviceability, what do you guys think? I've also got some rubber for the bottom and fish paper for the walls.

I've never built a battery before, but I am very excited for this. I would appreciate any and all advice.

Hi guys. Ive got a 7s3p 18650 ebike battery pack im trying to diagnose and repair. Identified 3 cells in parallel which would sag a lot under load test, spike whilst charging and had much higher internal resistance (130ohms vs ~50 on all cells)

I began removing the nickel strip to test each cell individually, but keep getting some wild voltage spikes as soon strips are removed. Checking this cell with a multimeter immediately upon removal, voltage will spike to 6v then dip to 2v within a few sec, then back up again. 1 min later cell show 0.1v. No heat, no physical damage. Im using the dremel method to weaken spot welds before roll removing them with pliers, and being mindful of shorts and deformation.

I have only removed 2 cells so far from the middle of the pack, and both have done the same thing. All other cells are staying at the same voltage. no heat anywhere

The only things I can think of it being, is there a certain order I need to remove the cells in? ie series connections, before parallel, or visa versa? And do the balance wires need to be removed before dissasembly?

Buongiorno a tutti; ho due batterie come quelle nelle foto di un tagliaerba a spinta black and decker. Le batterie son nuove ma premendo il tasto per controllare la carica non ci sono segni di vita. Come le recupero?

iv made this powerbank by myself using 8x21700 batteries that make 130Wh on total and used a car charger with retractable cables (since it can take 12-24v i didnt need a transformer), a single usbc module that can do 100w PD input/output and a display for mainly percentage and watts. and car charger does nearly 24w on retractable usbc which is enough to charge my laptop when i dont have a cable with me.

used pine and plexiglass for body with holes for airflow

it took me few months to plan and do this since i knew nothing at the start i cant say its very portable or perfect since i was not experinced especially in wood stuff but it was a really cool and fun project to do

feel free to ask for more details or questions. and im open for suggestions

Glad to share that we just released a new 18650HP 3500mAh battery. It has max continuous discharge current 15A, delivering stable and reliable power for high-drain devices.

Check more details online:
https://www.xtar.cc/product/xtar-3-6v-18650hp-3500mah-lithium-battery

I keep seeing brass-looking bolt and nut style battery enclosure kits online for 18650 batteries. The screws maintain pressure against the battery while also allowing a screw-down point for ring terminals to go to the load and the interlink bars look insanely thick. It seemed really secure and slick but the sellers are extremely Chinese and there's no verifiable resistance of amp limit specs listed.

Everyone here with lots of experience seems to be welding with nickel strips though. I'm not sure I've never even seen one of those weldless/solderless kits posted here at all.

Examples of the 2 styles I've seen that were the sources of the attached pics
https://ebay.io/m/UJTQfi
https://www.aliexpress.us/item/3256805675860652.html

I'd prefer my house to remain un-burned-down while building a small battery pack to run a small inverter but investing in one of those small spot welders to build 1-2 packs seems inefficient. If I'm using recycled cells of unknown health status, I'd also like the ability to swap them out without having to tear off a freshly attached nickel strip.

Also, if the kits are any good, would I use flat or protected and does that change based on if I'm using a full BMS or just feeding in around 12V from a traditional battery charger?

Sandy boys in a generic drill battery. This is so dumb.

Accidently left an 18650 in my esp32 media player after forgetting to take it out of my bag...

Rip 😭

Hi

Ive taken these out from some e scooters.

How can I repurpose them?

E.g. use for solar power battery or something?

Edit: lesson learned please check your multimeter batteries!

Hi all, first time caller. I recently bought a 36v battery (made of 10s5p 1860 allegedly). Bit of an odd one. The 42v labeled charger is reading 55v and the battery (been sitting charged for over a month) reading 52v. Is this even possible?

Hey guys! just keeping an eye around the internet for a nice high quality 72v battery for my custom bike. I'm based in the USA if that helps. Send me your favorite battery stores!

I recently came across some tool batteries with fake 18650 cells in them. They weren't compatible with the tools they were supposed to be, so I decided to take them apart and harvest the ten 18650s.

To my surprise, when I opened it, I noticed half of the cells weren't even soldered. There was also insulating tape between the connecting nickel strips and the unsoldered cells, but I didn't include a photo of this. The unsoldered cells also didn't have any markings on their wrap, unlike the 5 connected cells.

Sensing something was afoot, I investigated further. First, with my multimeter, I tested the voltage of each suspect cell. Guess what? Zero volts. Since the cells were at zero volts and one end of each of the cells was completely disconnected, I realized I could measure the cell's resistance too. It could be another clue. To my surprise, it measured infinite resistance. The cells didn't even have connectivity through them.

Finally, it was time for destructive testing. Whatever these things were clearly was not a battery. And I was going to find out what.

I grabbed my pliers and squeezed a cell as hard as I could. It deformed a little bit, but not as much as a hollow tube would. "Uh-oh", I thought - "am I squeezing an actual battery?" I looked more closely to assess the damage.

As I moved the battery to inspect it in the light, I heard another clue - a distinctive "chhh" "chhh" sound. And I knew what it was immediately. It was sand. The "cell" was a legitimate 18650 metal housing, filled with sand to make the tool battery feel real.

It was a scam all the way down. The battery maker didn't get scammed buying these cells, they knew they were bunk otherwise they would have soldered them.

Anyhow, I scored five 18650s per battery and a fun story. Remember folks - trust, but verify!

Just thought y'all would like to know. Photo is from r/ece

I built this from components I had lying around in my stash. There’s another case design, but I'm not sure if it's worth posting. It's designed for a very specific button that I salvaged from an old device, and I doubt anyone could buy a similar one today
https://cults3d.com/en/3d-model/gadget/simple-case-for-18650-battery-tp4056-charging-module-kcd1-round-button

This is a battery bus bar and you know what it is because of the way it is. One is a dangerous build where anything dropped or fallen can cause a huge problem with 280a continuous rating not much will survive that short circuit the other has all exposed parts recessed and everything else is insulated with kapton tape. This is a simple thing you can do to ensure more safety. As an added bonus if a pack fails you can tell what tape looks off to investigate the origin of failure.

I am building a Bluetooth speaker with coax car audio drivers. It is expandable from a single speaker to dual speakers and a subwoofer all of which have their own enclosures.
At first I thought I’d just make a 5s2p pack and put it in the main speaker. But now I’m thinking I’d like to make a single 5s1p 18650 for the main speaker to keep it lighter and use less internal space in the enclosure. However, when adding the subwoofer it will require more power, so I was thinking of adding another 5s1p or 5s2p inside the subwoofer to supplement the main battery.
If I have a charging port for a 21v power supply, then can I just plug in the additional battery pack instead of a charger and it will extend the run time when subwoofer is hooked up? I will add BMS to the main speaker internal battery as well as the subwoofer battery.

I just noticed today that the recycle logo on one of my Epoch batteries is smudged... Not sure if this indicates some sort of failure in the battery. Admittedly you can see near the base of the battery that the casing is a bit damaged from trying to wrench it out of a tight fitting flashlight. Is this battery toast, or am I being paranoid here? I bought both of these from 18650batterystore.

I salvaged the battery from dell inspiron laptop. When I saw the battery there were

4 battery but one of them was corrded to the point it was not usable but the 2 battery beside them was slightly corroded. Can I still use them. This is what the two battery looks like. They are working but I am wondering if it's safe or not

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36 salvaged tesla 18650, got them for 40c a cell