This battery was originally intended to be used on a Honda dirt bike I was building but I figured I have enough projects going on right now so I just kept it in a configuration that would fit in the 72v Voloci. It was going to get folded in half to be a cube battery...And if i ever do build the Honda it will need a much bigger battery than this
These cells are Eve 7.5a 18650 cells in a 20s10p configuration spot welded with Kweld. It has a 60a continuous BMS which is being reused that was taken out of a junk Ebay BTR pack that has a few cells puff and leak. The worst part of the pack build was extending all the tiny BMS wires that were cut very short
I got these batteries from the 18650 battery store website just like the 21700 40t Samsung cells, if i remember correctly I paid only $2 per cell on a black friday deal (so $400 plus shipping)
Here are a few pics of the build process, I know alot of this build is not perfect but I got it slapped together without spending any more money than the original cell purchase which was my main objective
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Pic of the Ebike corner of my basement over a year ago
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I still have some more work to do on the pack today, but my neighbors car battery died and he needed some help while I was outside cutting the PVC sheeting to cover the sides of the pack. So I used the rest of the daylight on assisting them
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Threw the pack on charge with the Cycle Satiator and everything looked to be in good condition! I cannot believe it took me over a year to complete this for no reason...it wasn't that bad
Thanks for your concern, but even major battery manufacturers make packs this same way. They do have a plastic protective layer over the positive already, would another layer make it safer...yes I will agree. But they are certainly not a requirement by any meansSorry to say but that battery is crazy dangerous. Have you missed to add cell insulation between the groups and insulation pads at the positive terminal? You are most likely to get a short circuit due to wear on the cells plastic cover due to vibrations.
That is not relevant to spot welding in any wayDon't trust everything you see on commercial photos![]()
Yes I see your cause for concern and appreciate your input. I do however own my own home(do not live in a multiplex or city) and put all of my bikes in a 10x12 shed that I built myself so if anything were to go wrong I would be the only person liable. I have been on this forum over a decade and I have yet to have one battery fire...I would obviously post it here if anything were to happenIt was a joke! I hope your battery does not fail due to missing insulation, I just think its important to bring up since it can be catastrophic if battery groups shorts and its a common fault that is easy to prevent.
Regarding "major battery manufacturers make packs this same way", maybe so but that does not change the fact that its dangerous. I seen multiple builds burn up because of this.
Your battery build looks nice and clean!This battery was originally intended to be used on a Honda dirt bike I was building but I figured I have enough projects going on right now so I just kept it in a configuration that would fit in the 72v Voloci. It was going to get folded in half to be a cube battery...And if i ever do build the Honda it will need a much bigger battery than this
These cells are Eve 7.5a 18650 cells in a 20s10p configuration spot welded with Kweld. It has a 60a continuous BMS which is being reused that was taken out of a junk Ebay BTR pack that has a few cells puff and leak. The worst part of the pack build was extending all the tiny BMS wires that were cut very short
I got these batteries from the 18650 battery store website just like the 21700 40t Samsung cells, if i remember correctly I paid only $2 per cell on a black friday deal (so $400 plus shipping)
Here are a few pics of the build process, I know alot of this build is not perfect but I got it slapped together without spending any more money than the original cell purchase which was my main objective
View attachment 329678
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View attachment 329676
View attachment 329675
View attachment 329674
View attachment 329673
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Pic of the Ebike corner of my basement over a year ago
View attachment 329671
View attachment 329670
View attachment 329669
View attachment 329668
View attachment 329667
View attachment 329666
View attachment 329665
View attachment 329664
I still have some more work to do on the pack today, but my neighbors car battery died and he needed some help while I was outside cutting the PVC sheeting to cover the sides of the pack. So I used the rest of the daylight on assisting them
View attachment 329663
Threw the pack on charge with the Cycle Satiator and everything looked to be in good condition! I cannot believe it took me over a year to complete this for no reason...it wasn't that bad
I completely agree with you on the overhanging nickel strips that is the one thing i also noticed they should get trimmed down just incase!Your battery build looks nice and clean!
2 Questions, why did you choose not to use cell holders?
Also, I noticed on the ends of your nickel strip there’s sharp edges sticking out over the insulated wrap of the cells. It seems that through time with vibration that could dig into the insulated wrap, short-circuiting the battery? I’m a complete noob when it comes to battery building. I’ve been trying to absorb as much information as possible before I start my first battery build.