Absolutely amazing educating video! Keep up the nice work! (P.S. Audio gain could be improved)
@sashaprzybylski
Ай бұрын
Thank you!
@68HC060
21 күн бұрын
Clever girl. 😃 -I assemble and disassemble battery packs for a living. You can easily add thermal protection to your charger. Connect the positive wire from your charger inlet to one or more thermistors in series, where the other end of the PTC-string will go to B+, the positive terminal on your battery pack. Connect the negative wire directly to B-, the negative terminal on your battery pack. Edit: Make sure each thermistor touch one or two of the cells, otherwise they would have no effect. -I've seen packs with 3 thermistors in series. There are basically two types of thermistors, NTC and PTC. NTCs are cheap and PTCs are more expensive, however, you can't just pick the cheap NTC thermistors for thermal protection, because as temperature rises, the resistance drops on NTC resistors. On PTC resistors, the resistance rises as the temperature rises, this is what we want, because if a battery cell gets hot, we want more resistance (and thus less charging power), that way we'll "stop charging" when temperature rises. -Investigate a little more about NTC and PTC before you begin (and you'll also have to find out what values of PTC resistors you want to use, depending on your pack. Another thing you want to know about, is heatshrink. When you solder two wires together, you leave an exposed part of the wires. You'll definitely want that insulated, so it won't short-circuit with another exposed part of another wire (especially B- and B+). Heatshrink comes in many different sizes. Here in Europe, where I am located, you'll find them in for instance 3mm, 6mm, 9mm and 12mm diameters. Most of the time they have a shrink-ration of 3:1, but there are also some that are only 2:1 (a 3mm heatshrink tube will shrink to 1mm if it's 3:1, but if it's 2:1, it can shrink only to 1.5mm). Now, to shrink a piece of heatshrink, you'll need a "heatgun". You can use a hairdryer if you don't have much money. It's all about getting the heatshrink hot. Make sure you overlap the insulation of the wires by about 10mm on each side. So if your wire has 5mm metal exposed, your heatshrink should have the length 10+5+10mm = 25mm (approximately - it can be longer). Some heatshrink come with glue on the inside. That makes it stronger but also stiffer. -for your use, you can use either; I'd use heatshrink without glue for thinner wires, but for thick wires (with lots of current going through them), I'd likely pick heatshrink with glue. When you disassemble battery-packs, the only important thing you should keep in mind, is to not short-circuit the terminals with your side-cutter. If you disassemble a 1P or 2P package, you will hear sparks, which may startle you; it won't get much worse than that. But if you work with anything above 4P, you may want to go slower and safer, such as ... putting tape over the nickel, which you do not want the side-cutter to touch. Kapton tape is a good type of tape for this purpose, but as it's very thin, you want several strips (2 or 3) on top of each other, before you start. Even though you've insulated the nickel-strips, try avoiding touching neighbouring terminals. Start with the largest nickel-strip (one spanning over several negative and positive terminals). Example: A 4P7S pack might contain a 2x2 nickel-strip, then several 4x2 nickel-strips and a final 2x2 nickel strip. The first thing you'll want to do is to flip the pack over, so the 2x2 strip is on the bottom and you'll see a 4x2 strip which is connected to that first group. It will have a neighbour 4x2 nickel-strip, which you should add 2 or 3 layers of Kapton tape over, before you start. When that's done, you can safely remove the first 4x2 strip. After doing that, you can remove the Kapton tape (save it for re-using), flip the pack over, add the Kapton tape to the 4x2 strip neighbouring the 2x2 strip and remove the 2x2 strip. Continue in the same manner, and you'll never see any sparks. -It's a little difficult to explain, but once you've gotten the idea of it, you could make a complete video about disassembling battery packs. 😃 -Oh, and when you spot-weld, you should weld the positive terminal of each cell with two spot-weldings (that's 4 "dots" on each cell), the negative terminal should have 3 (that's 6 "dots"). This is maiinly because there's not much room on the positive terminal, but also because some cells have thick negative terminals, which can be hard to weld well. Last tip: Keeping a distance between the cells in a pack is good for you, because if one cell gets hot, you might avoid thermal runaway if the cells are far apart. Your switch (between charging and discharging) might spark and after X uses break completely, this will likely happen if you connect the motor first, then switch to discharging. You don't need a switch on the charger, especially not if you use PTC resistors for thermal protection. I'd recommend having a fuse on the discharging side. This fuse should probably be below 30A in most cases. A fuse on the charging cable could be about 5A...7A. You may even want to add a reverse-polarity protection on the charging side (a 1N4001 will do just fine). Now, have fun and don't make too many sparks. 😉 Edit2: Oh, and one more thing: If you use used cells, you'll need to test each cell and sort them according to their internal resistance and also how much capacity is left in each cell. It's true that some Tesla cars use 18650 cells, but some people say that their cheap 18650 cells are the same type that Tesla uses; this is very likely wrong. Apart from capacity (Amp-hours), a cell can be high-current discharge, which means some cells can be discharged at for instance 10A, where others can be discharged at maximum 1A (or even below that). If you try and discharge a 1A cell at 10A, you risk that it will break (explode in worst case, so make sure to investigate if the cells can be discharged at the current you wish). A pack of 4P will allow you to discharge at 4 times the discharge rate for each cell, it'll last 4 times as long before you need to recharge it, but it will also be 4 times as strong/dangerous (4P isn't so bad, but avoid short-circuiting an 8P configuration by accident).
@TheWillDConstruct
Ай бұрын
This is BASED, and that looks way better than my first liion pack.
@sashaprzybylski
Ай бұрын
ahaha thank you!
@currydude7
Ай бұрын
Killer! Can't wait to see you blow up as a youtuber =] Good luck with your future builds!
@muhammodmostofa1413
21 күн бұрын
if you dont mind please talk a little slower..english isnt my first language so its a little tough to understand you.But loved the video.Keep it up
@AlanGibson7
18 күн бұрын
use youtube to speed up or in this case slow down the speaker. I played her video at 1.25x speed. Other speakers, i go up to 2.0x speed. So @Sasha, talk your speed, let the listener, do the speed adjustment.
@imaginationscene
20 күн бұрын
Very interesting, subscribed and question: How would you go about designing a battery back for a ebike?
@68HC060
17 күн бұрын
Here's my best tips on designing a new ebike pack: If you're designing for a new ebike, I'd recommend that you design the pack, so it can be easily renovated. That means: Make it possible to open it, change cells and close it again. -Avoid using "China-cells"; those are cheap and actually dangerous. I'd probably go for Panasonic, Samsung or LG cells (2.6Ah and up). Use a BMS; Daly BMS will work just fine; you should be able to get an affordable one. If you design your own BMS, I recommend not making it a "smart BMS", eg. one that does everything on one PCB and requires communication between the bike's display in order to work. We see them break all the time. Avoid being too smart about making the battery water-proof. Most of the water-damage we see are in enclosures that are "water-tight". The best battery I've seen has holes in the bottom, so any water will run out. These never gets damaged by water. I don't know what to recommend for charging-plug; most I've seen break easily, but my top-recommendation would probably be XLR and DC-barrel (yes, that max. 2A plug, which is used everywhere!) For battery-indicator, I recommend a simple LM324 (or even LM339). Usually packs are 7S (25.2V) or 10S (36V). A pack should be 3P or more (usually 3P tp 6P). Make sure there's at least 5mm extra space in the enclosure on each side of the pack and 5mm extra space on top and avoid screws in the mid-center of the enclosure. It's best to be able to build the complete pack, then put heatshrink around it and drop it into the enclosure. Do not forget thermal protection (PTC) - especially during charge, but also while the bike is powered. Use a 5A ...7A fuse between the charge-port and the pack. Use a 30A fuse on the "discharge port". Design battery-holders that are production-friendly, but also renovation-friendly (eg. easy assembling, easy disassembling). When you build your pack, don't be afraid to use fiber-tape and Kapton tape. Finish up with heatshrinking the pack (including the BMS). It'll be a good idea to design your holders, so one of them can contain the BMS. Avoid using silicone, it's not production-friendly and definitely not renovation-friendly, thus "bad for the environment", because the entire battery is likely thrown out and not recycled. Ensure your nickel is thick enough (0.1 ... 0.15mm thickness should be fine). Thin nickel weld easily, but may melt (like a fuse) if the bike is drawing too much power. Thick nickel requires an expensive welding machine. Always insulate between pack "modules", so you won't go "boom". -I recommend fiberglass sheets (like PCBs without copper), they don't melt and they insulate. Insulate your soldered BMS-wires using heatshrink. Make sure you have no exposed metal in your pack (including wires). Always use proper insulation; never tape, hotglue or silicone. Silicone will damage the insulation on the cells over time. Use proper connectors. Try not to use flimsy connectors. I've seen so much of this; they break, the factories glue them together (what's the purpose of a connector, if it's glued, anyway?). When choosing connectors, just make sure that the connectors you pick, won't fall out by accident. An ebike shakes a lot when in use. Finally ... Put some foam-blocks (10mm x 30mm x 20mm or the like) on each side of the battery pack, so it sits tight in the enclosure. Also put some foam sheets on top/bottom of the pack. You can put foam sheets on the pack, before heat-shrinking it, but the foam-blocks should be outside the heat-shrunk pack. I hope this was useful. If in doubt of anything, search the net, ask people who work a lot with batteries. And best tip: Safety first - always. 😃
@imaginationscene
16 күн бұрын
@@68HC060 wow that was way more informative than i expected anyone to reply, I'm new to this so your guide and advice is very appreciated thank you so much. 🙂
@68HC060
16 күн бұрын
@@imaginationscene - Anything I can do to help. 😃 -In addition to the above, I recommend getting "basic electronics knowledge" - unless you already know. Eg. You need to understand Ohms law ... 1: Voltage = Current * Resistance 2: Current = Voltage / Resistance 3: Resistance (Ohms) = Voltage / Current 4: Power = Voltage * Current -Those are the most common. Also, to calculate the total resistance of several resistors in parallel, this is the formula: Rtotal = 1 / (1/R1 + 1/R2 + 1/R3 + ... + 1/Rn) Series is much easier: Rtotal = R1 + R2 + R3 + ... + Rn. For capacitors, it's "opposite": Parallel: Ctotal = C1 + C2 + C3 + ... + Cn Series: Ctotal = 1 / (1/C1 + 1/C2 + 1/C3 + ... + 1/Cn) -If you know those two things, you'll become an expert in a matter of weeks; especially if you know a little about Arduino or similar (eg. ARM-Cortex microcontrollers). Learning electronics through using microcontrollers is probably the easiest way to get electronics knowledge. Just remember: The more battery cells you connect in parallel, the "stronger" the battery will become. You'll be able to melt metal with just a few battery cells, so make sure you go slow when experimenting, taking care not to short circuit the cells. -For your own safety, you should work with cells that are almost fully discharged or just old used cells that are almost "dead". This is a very good reason for not throwing away old cells. Avoid prismatic cells, they can explode much easier than the cylindric (for instance 18650) cells. Note: At work, we recommend people to avoid purchasing batteries that cannot be refurbished, so it's a good thing to make a product that will be recommended by those refurbishing it. 😉
@MegaKrustyman
23 күн бұрын
KZitem recommended your video after I watched another one on recycling disposable vape batteries to make a high voltage, high capacity pack. Maybe you could do something similar, highlighting the safety precautions of discharging and cell balancing. Nice work on this though, turned out great!
@sashaprzybylski
22 күн бұрын
thanks!! could you share the link to the video, if you still have it? sounds super interesting!
@@sashaprzybylski I tried pasting in the link but I don't think you're allowed to include full links in comments. It's KZitem slash watch?v=ehp23hrrEHY
@MegaKrustyman
22 күн бұрын
@@sashaprzybylski The video creator is Chris Doel
@HintenLinksUntenLP
22 күн бұрын
Wait, you too? That was literally the last thing I watched 😄
@AcrosstheNanoverse
Ай бұрын
This is so cool 🤩 Thanks for sharing your process. I'm glad it worked out safely! I'm excited to see what your next project will be...
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