Hey everybody. So I finally finished diagnosing my battery pack and I’m getting good voltage through the cells but nothing comes out of the bms. I was just wondering if there’s any way I could get the same, if not, something similar to the bms I have right now so it’s easier to plug and play. This is my first time working on something like this but I have a friend who has some experience building batteries solder a new one back on. I’d really appreciate an eBay link or I can buy one off of you if you have it. Thanks for reading : )
FYI, this is a bms from an Acedeck Stella S3 and is a 13s2p if that helps. Let me know what else I can provide to help find this.
My thoughts: That’s proprietary, and you’re not likely to find a straight swap out. It has a bunch of FET’s on it, so it’s obviously being used for discharge protection.
Maybe you could try searching for the number printed on the bottom of the PCB, but that will probably lead to nowhere. If the charger is 42V, then it’s 10s and will have 11 balance wires. You could search for “10S BMS” and see what comes up.
If it were mine, I’d see two options. 1. Repair that BMS (but it doesn’t even look like it has balancing shunts so I probably wouldn’t bother). 2. Build a new enclosure, battery, and replace everything. Then I’d keep buying more used evolve’s because they were cheap, and make bigger batteries for them. Then I’d start buying old longboards, and building enclosures to hold even more battery. It would likely lead to an unhealthy addiction to electric skateboards, in which it’s difficult to stop starting the next board prior to finishing the last.
I hope you find something and don’t have to become as mislead as myself. My neighbours thought someone was cooking meth, but I had to admit to doing fibreglassing every single day - causing the smell.
Good luck!
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Then after you finally get the insane range and power you want start making short boards and light edc boards until you find eskate parts everywhere in your house and car. You wake up one day from a dream about carving the freshest asphalt after finally nailing the hand down heel side slide to realize you’re pushing 70 and still pushing once in a while because it just feels good…
Or get a nice smart bms with Bluetooth or a cheap but good daly. Llt smart bms are a little big but can be found cheap direct from the manufacturer website.
Also do you really want to put a bms back in after all your trouble taking the battery apart and putting it back together if it was obviously the weak link here? I wish you luck in finding that bms but I personally feel like it will be a bad investment of your time and probably cost the same or more than a better more reliable bms.
The hardest and most dangerous part of swapping in a new bms will be getting the balance connector changed to the new bms layout and type - most of the new ones ive been using have switched to locking jst connectors which means splicing the old wire onto the new one which is stressful. If you do come back here for the process. You can setup the bms in bypass if you need to keep it small and compact as the esc will prevent over discharge.
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I agree with this man of literature. However, one thing I would like to point out.
If you use a dumb BMS, and choose to bypass it, with new cells this is relatively safe. Personally, I bypass with a fuse although I notice most people dont. Anyway, that is irrelevant for this discussion.
If your battery is out of balance, or due to whatever reason the P groups have a differing capacity, then you never know, and nor does the ESC - that one P group may have over discharged. You could put an LED to show the output of the BMS as a precautionary measure.
I bought three thousand used cells, from public scooter recycling. Some had lived in rivers, others had failed BMS, many cells had dropped to 1 volt from being in storage, all sorts really. Cells with a high self discharge rate are on my mind more than the minds of others who use premium, new cells. Please don’t judge me for taking my chosen risks with battery. I’m more terrified of cars on the road, and getting cancer.
Another option is like what I take on the plane travelling for work. It’s an acoustic long board. I drink beer, and use the energy to power my foot.
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I like this idea. Just like a pilot light.
Just an anecdote, i was using a 10a4p pack as a big ass power bank feeding a bunch of LEDs with a daly bms not bypassed. I assumed as long as the bms was not bypassed it shouldn’t kill the cells but would stop providing power if voltage got low or a cell group died or something. I left the leds running overnight keeping all the hippy ravers entertained. The next day the pack would not charge and in testing I discovered it had been over discharged to the point of failure. 
i wont use dumb bms anymore and have developed trust issues. Even if the hardware is nearly identical between smart and dumb bms i can oversee the smart bms and keep an eye on things.
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Yes. It’s important to keep the ravers happy.
I remember when MR16 LED’s were a new thing. I was young, and the world felt like an amazing place full of hope and opportunity. I brought with me, to the raviest of raves, my collection of SLA batteries normally reserved for pointing mountain bikes down hills in the depth of night.
As ravey day turned into ravey night, I went on a journey to fetch sticks. I favoured the long and slender type, and created a campsite light pole.
One thing you have to be wary of is that when light does run all through the night, like moths to a flame, the light will attract the muntiest of Munters - mostly individuals, and less likely in packs. It’s just something to be wary of.
I like smart BMS also. Not just because the function is required, but for all those times you would otherwise be facing anxiety to the point of the dissatisfaction that comes with having to drop off ones enclosure and reach for the multimeter. Life’s just easier when you’ve got a few smarts.
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I feel personally attacked
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I’m awefully sorry, I really didn’t mean to offend any Australians!
In reality, real Munters probably don’t come here to exchange ideas and opinions. They’re probably all out doing muntery things, or getting munted. Hmm…
Now, I must say thanks. I think I took your advice from memory, and bought the radium motor munts from Jesse for my 1kwh thane wheeled and flexible evolve GT. Haven’t used them yet, as the spare Chinesium mounts are still holding up with new years eve scrapmetal alloy brace.
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I really appreciate everyone’s feedback and as much as I would love to develop an unhealthy addiction to eskates, I’m still only in college and can only wish to afford an addiction like this.
I’d also like to add a note that the bms used to show perfect voltage when I kind of pushed the cable back into place if that makes any sense. Something like this,
And when the cable was scrunched in the enclosure it showed no voltage.
I suspect there’s something loose connecting to the bms but have no idea what’s wrong. I know I’m holding out a lot of hope in this battery but if there’s any shot I can fix it, I will try my best to do so. Once again, I really appreciate your help.
That seems like an open if Ive ever seen one, your bms could still be good and either the joint at the bms, the wire to the connector, or the joint at the connector is bad. That can be fixed by swapping in a new connector cable.
Test with continuity setting (ohm on the multimeter or possibly the diode test setting) between the connector and the bms and the connector and the positive battery terminal. Inspect them very closely and look for broken wire or solder joints. That could be a $10 fix.
Also eskate doesn’t need to be super expensive, thane and budget builds are fun as hell. You just need to take into consideration that you will probably need to double your budget if it’s fully diy as there are a lot of unforeseen costs that pop up until you get the hang of it and what you’re in for. Frustrating as all hell but satisfying once you’ve gotten a build dialed 
Old mates right. It doesn’t have to be expensive, but it probably will be. If you learn plenty, that’s what matters.
No matter how your life turns out, you’re going to need a descent soldering iron. A cheap temperature controlled copy of a Hakko is enough. I’ve bought one once which was suprisingly good considering it was from Ali.
I also tried cheap solder on AliExpress. It was shit, don’t waste your money. You’ll need a good “no-clean” flux pen from a reputable source, I tried Ali flux pens - money and time I will never get back. You can cheap out on a solder sucker, even if you don’t think you need one, you’ll use it. Same goes for solder wick, just don’t run it too hard on little chips and bend the legs. These things over time will save you more than they will cost, I assume.
I also have other soldering fluxes I use. Some leave a conductive reside but are better on copper wires, especially if there is corrosion. Don’t use those types on printed circuit boards. I’ve also used Ali gel flux in a syringe, despite it testing as non conductive, the reside caused hall sensor inputs on a vesc I repaired to not operate, and I had to do a lot of cleaning. Flux choice is important. I use my hot air SMD thing a lot, that’s been worth owning. So have a couple bench top power supplies and an old fluke portable oscilloscope on rare occasions.
I used to repair a lot of audio amplifiers, until I had better things to do with my life. Sometimes the sun would rise before I would give up on a car audio amp when I was still learning. You learn more from getting things wrong, than from getting things right. Personally, I feel soldering is an essential skill for every person, so you might as well start young. In New Zealand, the kids learn about all sorts of stupid stuff. The soldering skills will be way more useful than half the crap the teach these days.
Poor connections to your balance connectors could also cause the BMS to switch off. The whole BMS is relatively simple. The data sheet for the chips will likely even show a circuit diagram of how they are implemented. The chips just switch off the MOSFETs if the voltage isn’t in between about 2.8v and 4.3 volts per P group. There will be output protection, probably by measuring voltage over a shunt resistor to calculate the current.