PSA: Be careful assembling Li-ion Battery packs

that was on the grand tour, not sure if they have petrol companies as sponsors since it’s mostly amazon, and some dhl sponsorship monies too.

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But the thing about conspiracy theories Is that you can just go nutz :smiley:

Back on topic: Live and learn :frowning: hope this doesn’t happen to others.


GrandTour. It’s backed by Amazon. Jeremy fired TopGear.

Sorry to hear you lost your board. :frowning:

If it makes you feel any better building battery’s is difficult. Just yesterday a Tesla caught fire for no reason the video is not that different from yours.

Maybe the community should start opening lots of products with lithium battery packs to see how we can make our diy packs more reliable.

Cell level fusing is an idea that chaka first brought to this community. This defiently decreases battery fire probability, but introduces another issue, which is when those fuses blow, so can your acceleration. On powerful boards like this, you would get thrown off.

This is the main reason I don’t use fuses. It’s a trap waiting for me to hit, and it will cause slams (as I saw happen to jinra in person the first time we met)


Damn, so sad to see things go in balls of fire… I know you’re out of the industry game, but you still building another board? So far, my cell-level fuse battery pack is holding up in my Evolve, but I was so paranoid every time i charged or rode the thing. Kept imagining it would blow in the middle of the night and burn the damn house down.

i think cell fuses makes sense in huge P groups, ie tesla’s 6s72p, where the remaining cells in the P group can make up for the lost cell(s). in a 12s3p tho, missing a cell in P group without it being addressed quickly will be a massive problem.

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With the carvon v2’s, because the kv was so high, I could lose reception under full throttle and recover. I can’t do that hummie a lower kv lower top speed motor like the hummie v4’s.

I’m rebuilding, but In a hole still. I’m actively applying and interviewing now though. 4x focbox or vesc6.4 is not cheap. I’m using one of hummies decks with the @psychotiller enclosure with zippy 12s (4x 3s) rewired on the tabs so they could fit and with a 12s balance plug. Everything’s together except esc’s.

Did you use insulators on your cells?: download

Did you solder the copper strips onto the cells? Maybe one of the solder joints failed?

i can’t rly picture the copper strips, can you post a pic?

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Sorry for the loss, glad no one was hurt.

Personally I think lion is more dangerous than lipo in a skateboard due to the increased number of connections and short points compared to a lipo setup. Also if there is a fire they shoot off like little rockets while lipo’s stay still.

Vibration is a big issue with all the connections in an esk8.

This wouldn’t stop me using lion but you have to be even more careful with pack assembly. Most of the fires on this forum have been lion and happened while ridding. I only remember one lipo fire and it was due to a screw from the enclosure penetrating the lipo pouch.


Looking at this post scared the hell out of me. I built first pack and I was about to start using it until I realized I didn’t follow all the necessary precautions. For example I didn’t use fishpaper, or positive terminal insulators as shown two posts above. It kind of seems like the nickel strip I used is a little wide. Can you guys look at my first attempt at battery making and see if you think it’s safe to use? If not, is there anything I can do at this point to make it safe? I was told that once the strips have been soldered onto the positive terminals, it’s too late to add insulators. Check out the pics. Let me know if it’s unsafe or fixable. 12s4p from 30q cells.


ouch - sorry to see that man…

Brother I feel your pain, I’ve been there and it’s not fun, o also could ever detect the main cause of my Trampa catching fire but I know what I didn’t do.

I did use the round circles around the positives leads, but I didn’t use fish paper between each pack.

Did you use the circular fishpaper terminal isolators? Did you use fish paper between the packs? Do you have pictures of you battery build process? Did you isolate the charging port? Did you use fish paper between the cells and balance wires? Did you use bullet connectors between the battery and ESCs? Were you giving full throttle when the first cell started to vent? What was your technique to connect P groups?

Sorry for all the questions hope you don’t mind answering, but I understand this post has been created to prevent these kind of incidents and so are my questions.

Wish you good luck with the next build hope you do t get discouraged by this episode


I was thinking about putting m batter in a lipo safe bag

disassembling the battery would be a pain. maybe you can get in behind all the possible edges with something. can see if the welds are any good at the same time. but there are long spans of horizontal nickel strip which will be very rigid. theres a method people use with a bend which allows flex.

i also believe the lipos are ironically safer considering so many people are connecting 18650 packs having never done it before. I think especially if you want to get decent brakes on a high kv hub motor at higher speed, and have the battery max regen be possibly set high, lipo may be the best thing




Unfortunately, no

Yes, charge port was opposite corner of where the fire started.

No, but the wires where no under any pressure.

Positive yes, neg, no. Used the positive to turn the board off and on.

No, I was braking, was going maybe 20 mph, slowed down to around 10 mph and it started venting.

I used a copper strip on top of the cells to connect the p’s. This was all covered in electrical tape.

Yes, could have taken more precautions. The last li-ion battery I built did not have any issues, besides it was larger than desired. The only difference was I used copper stripping instead of copper wire.

I don’t works. Our packs are above 100wh and are to powerful for a Lipo bag

Lack of fish paper would easily be the culprit venting of the first cell, I guess P groups could have been rubbing against each other.

I don’t think thicker strips could have caused a short as once they are spot welded they don’t move at all, however the copper sheet might have cutted one negative isolation.

I need to understand this, I’m not sure what you mean. Did you spot weld the P groups and the folded the strip?

On the other hand, if something like this ever happens to anyone reading please go to the nearest shop, grocery store, office, building, business, etc., and ask for a fire extinguisher, no sane person would ever deny it.

In this scenario the mind just freaks out and says, sh!t there’s nothing I ccan do just wait it to finish, but remember it could take 20 minutes to finish or even more, so you just take out your phone and shot a video, I know because I did it myself and then banged my head knowing there were docens of shops around.

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