Hello everyone. My son and I are building a go-kart. We have all of the components, but when making the final connection, it of course arcs, and I wanted to make sure that the wiring diagram attached looks good to everyone. This is based on watching many different YT tutorials and I also had a few questions. I've been told that we should install a killswitch for the last connection and I'm not sure exactly what to buy for that.

The battery is 20 amp by 60V per the 16 series 3.7V batteries we're using, but when fully charged and measuring voltage with the multimeter, it registered at close to 80V. Our motor/motor controller are rated for 60V. I imagine after a 10-15 minutes of hard use, this voltage would drop. It has been sitting on my desk like this for almost a month or two and has dropped to 65V. This leads me to my questions.

1. What type of kill switch would you recommend? I put the link to one below that I think may work, but I'm not sure.
2. Is it OK to put 80V through the motor controller and motor?

We're so close! Once we get this wired and we can see the gear on the motor turn, the next step is just attaching everything to a frame, right?

https://www.amazon.com/AWBLIN-Disconnect-Voltmeter-Isolator-Application/dp/B0CQ4PCVLX/ref=sr_1_3?crid=E3FAQBU5GQ73&dib=eyJ2IjoiMSJ9.mLWbZdL3olcS7FDzN5A19KbRbp-GLLMhhCpmn7FcCe8GJcbvTTzDBSEM0CMj8jdImC-AdbQCJG6RGh5avrv5jaH9Io5LUGHHwVmCDKRcsQ4dIpmHET11iBq9HiBYWCmgBRBr1GIVnMl1ta_hZ1I0ZHGZk6haxfuIGLIXKWclIC3zDjyOfHgLOnIZXJDtBFa53bR0f0-AjOnjuvUjtYKoqi5lnX5Xsv-9z-BlRJCC7B0saYqBFdMvrvHgp_-qn93F2A4S7VQsGszX3rBAXsU3FGEJLTtod8jfuxfLu8gkmec.g2GZQ8Lso5V9Lv1V0EXA3mMR5SOQ3OdupOf2ZZ0aJEQ&dib_tag=se&keywords=60+volt+dc+gokart+kill+switch&qid=1732992749&sprefix=DC+kill+switch%2Caps%2C291&sr=8-3

https://preview.redd.it/9t9bxniy534e1.jpg?width=4000&format=pjpg&auto=webp&s=fab957988a9187d0eff2fc25396e440a190e064e

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https://preview.redd.it/00d45siy534e1.jpg?width=4000&format=pjpg&auto=webp&s=31a9ff346c69387532140fbc83b9864f0cae86af

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Hello there. My parkside 8 ah 20v battery keeps having issues.. i already sent 2 units back to warranty replacement, and the new ones still do the same.. basicly 1-2 cells gets unbalanced, so the bms won’t charge the pack more then lets say 70%.. its stuck on the orange light. The batteries supposedly have passive cell balancing..

What can i do with it without opening it to void warranty? What im thinking to do is discharge the pack, and start charging it back up, but with the slowest charging possible (1 Amp) to give time for the bms to balance the cells?

Help please

https://preview.redd.it/buy0h8dvrw3e1.jpg?width=4206&format=pjpg&auto=webp&s=934d936051f1287abcb9dfcf065fcc6ed1f3fd73

I know it's missing some parts, and before I finish it, I want to use it as a power bank, but I don't know which one for the USB-C board. By the way, it's 3s6p.

Thank you.

Can someone help me founding this bms? I can’t find it anywhere It’s a 6s for an electric scissor

Hey guys - can anyone tell me if there is a meaningful difference between having the balance tab like in image 1 or image 2 (where image 1 is closer to the cell terminal of the group being read, and image 2 is in the middle between the 2 cell groups)

https://preview.redd.it/4akdwqqs2t3e1.png?width=1130&format=png&auto=webp&s=20ed37b26dc1837bc997062a3ca7f55df72abe94

https://preview.redd.it/vj2q3hxt2t3e1.png?width=380&format=png&auto=webp&s=e4137dcd227954a09a9149a61fc5a5a3a2603208

So glad to share XTAR 21700HP 5000mAh 25A battery was released online! This 21700HP battery offers 5000mAh capacity and 25A continuous discharge current, making it perfect for flashlights, power tools, and other high-demand devices.

Check details online:
https://www.xtar.cc/product/xtar-21700hp-5000mah-25a-battery.html

https://preview.redd.it/le6b443tws3e1.jpg?width=1200&format=pjpg&auto=webp&s=711bc6bee64e7aecfd5081709ba2713a726e46c9

I’m trying to ship a large battery pack Approx 8”X8”x17” and 45 pounds.

UPS told me no.

FEDEX told me I had to go to one specific facility and then said I’d need the proper sticker and packaging but it would be fine. Then I asked more questions and they said I’d need to be hazardous product certified and it’s expensive.

How expensive? How much of an issue is shipping? Is it possible to find third party shippers?

I see that there are some other people on there that have also had a bad experience with jag35, but I'd figure I'd share mine. I've bought from them in the past (4 cell modem packs) and had a good experience, so I tried again with 3 cell modem packs. I bought 50 packs, so 150 cells total. They were pretty cheap, but I still had to ship them. I've taken half of the packs apart so far and have found NO usable cells. Everything was discharged down to almost nothing., reading below .5 volts. If I tried charging them up, they'd discharge to about 4v immediately after being taken off the charger, then to 3.4 v under 1 amp of load during capacity testing.

I know you get a few duds when you buy used cells, but if ALL of the cells were bad, they have to know something is up, there is no way jag35 is ignorant of this. I can't be the only one that had this experience. Last time I bought from them, I had around 15% of the cells be either completely unusable, or only good for very low current applications. This is basically what I expect with used cells. But this was a whole other thing. The sale was as-is, so all I have is my rage, but definitely use battery hookup for used cells, jag35 can suck a nut.

Hello I would like to know how should I start building my own BMS that has a constant current and constant voltage outputs.

Any help would be appreciated as this is for a current project I’m working on, (an autonomous vehicle powered by Li-ion 18650’s).

Everything I’ve found either fits standard size only, or claims to fit protected size just to have customer reviews saying they don’t. The holders are all way too tight.

Are ill-fitting holders and soldering the only options? Has anyone found a holder that actually fits?

newbie question; i have a 18650 based no name flashlight
the 1 dead no name cell inside says on it; 1800mAh 3.7V
but when i shop for cells i see they are also AMP rated
between about 5a to 30a - so which amp do i buy here?

i am aware of button top and flat top,
this particular flashlight works with either
as both + & - side has a coiled spring.

Hey guys,

I am planning on building my first battery, however, Im a little scared and somewhat concerned and was wondering if anyone here would be willing to help guide me as I build it.

Looking something like this but instead of aa/aaa I would want 21700 and 18650. I guess my search ability is terribly inadequate because anything actually meant for our sizes are 2 or 4 pack boxes like they get shipped in and I would much prefer to be able to easily cycle through my batts instead of trying to remember what batts are in what holder and having them stacked on the table. Any ideas on where to find? If I had a 3d printer I would just make my own. Anything similar and wall mounted is my goal. Thanks in advance.

https://preview.redd.it/x6sd151z3x2e1.jpg?width=1002&format=pjpg&auto=webp&s=541ec0c814bb3d5bd9c1a0e1f40b8807afed05fd

Hello there, I'm trying to build a power bank out of a 4s lipo battery pack. i got myself an ip2368 module and a 4s BMS, i wired it all up, the output terminals of the BMS read a little over 16V, and when i hook up the IP2368 it seems to power on fine (the leds light up at full power, and if i connect a charger the 4th led starts blinking).
but it seems i cant get any decent output out of it:
i tried plugging it into my phone - nothing, i tried hooking it up into a usbc -> power barrel 20V, and i read only about 4.5 volts on that.

I also have a fnirsi fnb58 tester, and even there, if i connect it to the IP2368 directly, it doesn't even power on, if i give it external power via the pc input it turns on, it reads the quick charge protocols just fine, but the voltage is always stuck at about 4.5-4.8 volts.

in all three cases, the board seems to power on (with 4 fixed leds, which opposed to what happens to when i plug in a charger, i think it correclty means i'm in output mode)

What's the matter? did i get a faulty IP2368? what else can i try?

PS: i tried also hookin up the batteries directly to the IP2368 without bms in between - just in case, and that yields the same exact result as with the BMS (which i expected since i see the expected 16V on the BMS output)

I have some questions

Im looking to make a pack from recycled cells with different voltsges 3.8v, 3.5v,4.1v and I am wonderig if there is an specific voltage the cells need to be at when I start to build it?

Can one series be 3.50,3.49, 3.50 and another series 3.79,3.79,3.80 for example?

Each cells are the same compacity. And how would I discharge or charge to the correct voltages?

i mean, how much more dangerous could it really be?

...asking for a friend.

Howdy Friends!

Anyone spot some cool 18650 powered electronics/gadgets out there?

I know this list exists: https://www.reddit.com/r/18650masterrace/wiki/devices/

But it looks like over half the items listed there are either no longer made or just dead links.

Cheers!

Tell me all the mistakes I made. (Before I turn it on)

I plan to weld 0.2mm pure nickel and 0.15 nickel plated copper for small form factor, small capacity, high drain packs.

I'll keep the cap bank at 14v for the sake of the 25v cap on the control circuit but am ready to change that out to a 1kuF 50v cap when I inevitably pop this one.

My purple board is the updated one where the octocoupler is driven from the control circuit and the mosfets triggers are stabilized by afformentioned cap so "the mod" is not required here.

Other than keeping pulse times super low with such a beefy power supply I don't think there's anything else too egregious I've missed. I guess I could build a flyback array for the output?

Has anyone used this: https://a.aliexpress.com/_mPcb5f9

I have a Ryobi Lithium-Ion 1.5AH battery pack, and I've been using it for charging my phone through a voltage regulator module (I believe it is 24v-12v regulated to 12v). I have 2AH and 4AH Ryobi battery packs, and both of those seem to cutoff at around 14v.

As far as I can tell, the 1.5AH battery packs don't have a voltage cutoff, and the system stops once the battery voltage reaches 12v, due to the voltage regulator module cutting out, not the battery. That equates to 12v / 5 = 2.4v per cell.

I actually just brought this pack back to life with a bench power supply after it was dead for probably over two years, and it was at 0.04v for all 5 cells. The standard Ryobi charger would refuse to charge it, but it's back to life now!

With that being said, is 2.4v per cell okay? It would be ineffective for me to add a low voltage cutoff to my system just for this battery.

EDIT: After cycling a few times, it appears that the under voltage circuit has started working again in the previously dead battery. It now stops at 13.8v / 5cell =2.76v per cell

I see all these posts not to buy from Amazon, but can you explain why I shouldn’t buy these? They are inexpensive and the reviews seem decent. I don’t care if I’m getting a bit lower mah. I would be concerned if they were dangerous though.

Jessy 18650 https://a.co/d/9IOyIW1

I am thinking of pairing them with this charger.

https://a.co/d/8sfOWZg