72v High Power Battery Build DIY
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- čas přidán 6. 09. 2024
- DIY build of a powerful 72v 40Ah lithium battery for my electric dirt bike conversion. Samsung INR21700 40T cells 20s10p, ANT BMS, copper and nickel spot welding.
I'm an amateur hobbyist. This is my build, and I hope it entertains you. Be sure you fully understand the subject of battery building and handling electric current before undertaking your own project.
i like how thorough you are building this pack
Really good battery build .
hey! Love the video! I'm curious about your dirtbike build, was it a gas dirtbike frame that you converted/modified to be able to fit motor QS138 an battery? checked you channel videos but couldn't find one
Thanks! Yes, it was an Apollo rfz. The 2 main mounts of the qs138 match up with the engine mounts on the bike perfect. The foot peg plate did not and required some cutting and welding. I also had to make an additional frame piece to support the battery and case. I didn't video much of it but I have a lot of pictures. I will say it came out great and really rips!
Wow, probably the best battery building video i have ever seen. Have you expirience a lot of voltage sag on that battery? What are the dimentinons of the battery? I am considering building a pack just like yours! Great job man👍
Thanks! I'm seeing a lot less voltage sag than my previous battery. I think it's partly the higher capacity, and also the heavier discharge wires.
Dimensions with the rubber shrink wrap are:
9.5" long, 6" wide, 9" tall American
240mm long, 150mm wide, 230mm tall Everyone else.
@@ebikebuilds4000 what size heat skrink did you buy? 300mm?
@sandernikolajvintherpeters3842 it was 290mm from an ebay seller. Unfortunately at last check, it's out of stock there.
@@ebikebuilds4000 Hard to find one for a big pack.. Im still looking for a 21s15p pack
🔥🔥🔥🔥🔥🔥🔥
Are you using nickel on top of the copper to make the spot welds?
Yes, it's actually the cheaper nickel plated steel. Normally that is less desired as a stand alone connection because of the higher resistance, but in this application, it's the copper that carries the current during use, so the higher resistance of the nickel/steel makes for better welds.
I'm trying to build an ebike battery myself and currently in the process of understanding it all. What determines the ability for a fully built battery to allow say a 100AMP Continuous discharge? Is it the nickel sheet's thickness? Or the amp discharge rate of the battery? I see that these Samsung 40T cells are rated at 35A. If I use one thats rated for 15A, can I still use a 100Amp cont. discharge BMS from ANT?
Trying to build a 72v20ah Battery. Appreciate any help and insight! Looking to probably just copy your build
Discharge is a combination of the individual cell characteristics, number of cells in parallel, the electrical connection between them, the rating of the BMS, and the discharge wires and connectors. So if you have cells rated for 15A and you want 100A discharge, you need at least 7 cells in parallel. The series connections between each P-group need to be able to handle 100A as well. The copper does that fine. Your BMS has to be rated for 100A continuous or better, and you probably want at least 6ga discharge wires and xt90 or qs8 connections for plugging it in.
@@ebikebuilds4000 This reply along with watching a few other build videos of yours really made it click in my head thank you!
Will pure nickel strip be able to carry that amount of amperage? Or will I need copper
@djmedia01 pure nickel strip should be fine so long as you series connect each cell. The series connections carry the full current of the pack, so they need to be robust.
@@ebikebuilds4000 Thank you so much for the info. Greatly helped everything click together for me.
hi what is the range of that battery if you ride at 30mph ?
I'm not really sure. I would have to figure out the amp draw on my system at 30mph. My best guess is it would draw somewhere around 30-50 amps at flat cruising speed, so around 40 miles. I use the bike for woods, trails, and hill climbs, so my power usage is all over the place.