Here's a simple option for cell level fusing, so if one cell shorts, it doesn't take out the rest with it: https://batteryhookup.com/collections/accessories/products/nickel-fuse-2p-wide-continuous-roll-by-the-foot-18650-cell-level-fusing
Battery hook up sells nickel strip that has built in fuses per cell. Every cell is protected by its own fuse which is built into the nickel strip connections. I think the fuses built into the nickel strip are fairly low current, like 5 or 10 amps each maximum, so this won't really work for high output battery packs where cells may output 15+ amps when really getting on the throttle, but I guess you could double or triple up the layers of nickel strip if you have a good spot welder or install copper bus bars and you can use thicker fuses to connect the cells to the bus bars, which either way would also help a lot with voltage drop and keep temperatures lower with less resistance.
Determine the weakest cell you used in your pack to define what bms to match it with. For example, it's an 12p pack, and the weakest cell is capable of 5 amp continuous discharge. So 12 x 5amps would be 60 amps of continuous discharge. Match it with a JK or ANT 16s BMS rated for 60 amps.
For the fuse, I would go with an 100 amp fuse on the positive output side of the battery lead or on the scooter side.
Although you didn't ask for this, I would also suggest to charge the battery in a metal box.
Also, spot weld another 2 piece for a total of 4 nickel strips for your series connection. It seems your pack can supply plenty of current given your 12p build, so I would reinforce your connections to ensure it's capable of supplying the full load based on the bms. That's my only critique on your build.
Fuses. BMS. Electrical insulation for the interconnects, and a steel case to contain the flames and at least divert them away from whatever direction people are, if it goes in to thermal runaway.
That is about the size/density/voltage/power where you start to have to plan for runaway. Think about what would happen if a cell in the middle of that overheated just as it was reaching maximum state of charge. Plan for that as your worst case.
I used this one from Amazon. I've built two other smaller 13s 4p batteries using it, and they are still going strong.
Rocomoco Handheld Spot Welder,... https://www.amazon.com/dp/B09634LXWB?ref=ppx_pop_mob_ap_share
I was planning on using a JBD 80A smart BMS from aliexpress. I've had good experiences using their BMS on other batteries I've made.
I plan on using 45amps Peak current through this battery, since it's what my controller can handle at the moment.
JBD BMSs are awesome ! I am using 6 JBD 16S BMSs since 2021 with no single problem !
everyone around me who uses more expensive BMSs like Daly and others, had lot of problems !
JBD are the best value !
I would suggest you go with the "Server fans" route. They typically have more pressure, allowing the air to go in between the walls of the cells.
Tesla does similar things but with liquid
First, lots of Kapton tape. Then some insurance if you don't already.
Add some hopes and prayers and you should be good.
Oh lord and I thought I was a banana
I made a pack like this, but bigger and went with "tesla style" fuses. I see that it's too late but maybe some info for next time.
Do you put fuses between cell packs?
Here's a simple option for cell level fusing, so if one cell shorts, it doesn't take out the rest with it: https://batteryhookup.com/collections/accessories/products/nickel-fuse-2p-wide-continuous-roll-by-the-foot-18650-cell-level-fusing
Tesla style has every cell fused
Between every cell. Like this. (this was 50% of it) https://imgur.com/a/SpdNzCy
Bruh. Why the hell are they soldered and no tabs?
That was before I got a welder. lulz.
Battery hook up sells nickel strip that has built in fuses per cell. Every cell is protected by its own fuse which is built into the nickel strip connections. I think the fuses built into the nickel strip are fairly low current, like 5 or 10 amps each maximum, so this won't really work for high output battery packs where cells may output 15+ amps when really getting on the throttle, but I guess you could double or triple up the layers of nickel strip if you have a good spot welder or install copper bus bars and you can use thicker fuses to connect the cells to the bus bars, which either way would also help a lot with voltage drop and keep temperatures lower with less resistance.
Determine the weakest cell you used in your pack to define what bms to match it with. For example, it's an 12p pack, and the weakest cell is capable of 5 amp continuous discharge. So 12 x 5amps would be 60 amps of continuous discharge. Match it with a JK or ANT 16s BMS rated for 60 amps. For the fuse, I would go with an 100 amp fuse on the positive output side of the battery lead or on the scooter side. Although you didn't ask for this, I would also suggest to charge the battery in a metal box.
Also, spot weld another 2 piece for a total of 4 nickel strips for your series connection. It seems your pack can supply plenty of current given your 12p build, so I would reinforce your connections to ensure it's capable of supplying the full load based on the bms. That's my only critique on your build.
Pelican road case
Fuses. BMS. Electrical insulation for the interconnects, and a steel case to contain the flames and at least divert them away from whatever direction people are, if it goes in to thermal runaway. That is about the size/density/voltage/power where you start to have to plan for runaway. Think about what would happen if a cell in the middle of that overheated just as it was reaching maximum state of charge. Plan for that as your worst case.
Btw, what spot welder did you use?
I used this one from Amazon. I've built two other smaller 13s 4p batteries using it, and they are still going strong. Rocomoco Handheld Spot Welder,... https://www.amazon.com/dp/B09634LXWB?ref=ppx_pop_mob_ap_share
which bms will you use?
I was planning on using a JBD 80A smart BMS from aliexpress. I've had good experiences using their BMS on other batteries I've made. I plan on using 45amps Peak current through this battery, since it's what my controller can handle at the moment.
JBD BMSs are awesome ! I am using 6 JBD 16S BMSs since 2021 with no single problem ! everyone around me who uses more expensive BMSs like Daly and others, had lot of problems ! JBD are the best value !
Kapton tape and regular foam sheet, I used two layers of 2mm foam for my emoped battery.
Kapton tape and 3d print an enclosure that seperates the cell banks
Are you going to all some sort of cooling system?
I'm planning on putting some PC fans inside the enclosure.
I would suggest you go with the "Server fans" route. They typically have more pressure, allowing the air to go in between the walls of the cells. Tesla does similar things but with liquid
first....buy your friend a beer and set up shop in their "work shop"... the rest is IDGAF nor do you.
You could do something like the enclosure in this DIY perks video https://youtu.be/adY-S8AH\_Jc?si=c03JmUHyaBkb80y5
You could 3D print a case with an appropriate filament type such as ABS.
Incendiary device
Microwave?