Sure but failure mode on an ebike is a non-issue compared to on a euc
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true,
But an ebike is just as capable of burning your house down whilst you sleep 
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I donât see a lot wrong with the post picture. Could it be better? âŚ, yeah⌠will it start fires? Likely not. Also @TheBoardGarage your work is gorgeous.
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As far as I have seen, this community holds the highest standards for pack building out there. I may be wrong. Please correct me if this is the case. I know that I put love and integrity into every pack that I build and try to make it the safest thing possible for what it is. ENERGY IS DANGEROUS there is no such thing as a completely safe battery pack. It doesnât exist.
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Haha good point
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not bad, Iâd imagine the mid section of the positive terminal needs to be abit recessed.
Think battery hookup had something similiar.
Only real problem I see here is that since its 4 conductors, those 4 conductors needs to be kept as identical as possible. In terms of width and length and when one blows, the other three is sure to come straight after. However, if one is blown and for some reason current goes low, three will remain and maybe something bad happened without you knowing whats up, everything looks fine when charging etc. Generally its a no no to parallell fuses, since theyâll never, ever blow simultaneusly. Dsnât matter how good they are, one is always bit weaker.
Think you have some testing to do 
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did you not see their fancy videos? they also have a video running it over with a car.
does @Battery_Mooch know about the batteries melting down after someone puts too long of a screw in the lid and goes for a ride?
hmm offtopic should be in CHI Batt threat or an xxr thread
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IMO cell level fusing is not a bad idea if done correctly.
But thereâs a fine line when making a fuse. Y want it so that that it wonât blow during heavy load but will blow during a short. For esk8 packs those numbers are quite close together.
In cars or ebike this is easy when cells are rated to only 5-10A per cell.
The old original Kaly packs with cell fuses were good. I once shorted a pack and it blew all the fuses for a whole P group. Probably saved the pack in the process.
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We have to go back and ask why is cell-level fusing being done?
If it is for marketing reasons and they are not claiming any increased safety then as long as the fuses donât decrease the safety of the pack or add new failure modes then theyâre fine.
If they claim that their cell-level fusing increases pack safety then we have to ask what failure modes/mechanisms does this fusing protect the pack from that wasnât already being addressed? Is the BMS not reliable? Are the cells not UN38.3 and EN/IEC62133 tested? Are cells being found with a higher than acceptable internal failure rate? Basically, for what safety reasons were these fuses added? What other safety issues still exist?
Cell level fusingâŚa good concept that needs to be properly applied to be effective, which is not easy at all. There is a significant amount of testing that needs to be done before approving this for a product.
If only three out of the four links blow does that leave the fourth link hot enough to eventually burn through the tape or shrink wrap during normal or heavy use of the pack?
Can any of the fuse links, when blowing, ignite the fishpaper rings? This is molten nickel weâre taking about here.
Have the links been tested under a wide enough range of environmental conditions? Do the links retain their original properties after hundreds of km of vibration and shock? Are the links properly sized for the cells they are using? If they are using more than one type of cell then do they have different size fuses?
Iâm not dissing cell-level fusing. I would use it in any esk8 pack I built. But it needs to be done properly and not just tossed in, assuming it always increases the safety of the pack.
Lastly, Iâm actually more concerned about the second image of the three in that Instagram posting. The one that shows them spot welding in the center of the bottoms of those cells.
This is where the internal spot weld is made between the metal can and the negative tab from the roll of battery materials. All of the manufacturers say to not weld in the center of the negative terminal of the cell, presumably because it can damage the internal weld. This is being done by a company that, on the same image, claims the âhighest standard of safetyâ?
Things that make you go hmmâŚ
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This is why I love your input 
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We tested fused nickel for our battery pcb that already have charge fuse and discharge fuse and bms inside the pcb so no balance wires. Also space between all cells.
Problem with cell level fusing with nickeltab is that it could melt and drop down on pcb and make a permanent short.
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Try telling the uni guys this and youâll be buried in playground insults about how you ride slow
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Par for the course.
Youâre talking about a company that can literally sell anything to a customer base with the loosest wallets in the PEV space.
They have basically carte blanche to sell anything and assert itâs the best thing ever.
The Onewheel base already is primed to accept products, because thatâs what Future Motion instilled. Thereâs only one maker of the product, so thereâs no productive critique. You canât go anywhere else.
And Chi is âhomegrownâ, as Iâve been told. They have a referral system, the assertion of innovation, and the continuing image of being the underdog that flies in the face of the Goliath that is Future Motion by offering people the âsafestâ batteries for the Onewheel.
Itâs their bread and butter. And itâs not likely to falter ever.
Criticism is met reactively, and then said to be part of the operation the whole time.
Also, most people wonât spend $300-700 on a battery to immediately tear it open and look for reasons why they unwisely spent their money.
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i would
but thatâs cause i like to take a peak inside
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Esk8 news approved. 
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just deflate your tires youâll be good to go.
I mean if the wires are thin enough they will just vaporize⌠hopefully.
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I think I know why they started cell-level fusing. (Or at least one of the reasons they kinda fasttracked it)
The Onewheel packs are an extremely tight fit. FM uses bolts with several different lengths in the Onewheels and some Chi customers swapped some bolts during installation.
You can kinda see where this is going but on some places longer bolts will go inside the battery compartment. There have been (I think) two instances where bolts have punctured cells which caused fires.
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