18650 battery tray

sore knee bike ride

New Member
Region
Canada
Will this work?

IMG_20230214_140601.jpg


More specifically with batteries in it and even more specifically in a 36 volt electric bike. The batteries are Samsung ICR 26H M

It is wired in series and the white wire is 16 gaije copper.

Thanks in advance.

-sore knee bike ride
 
I know the protocol, a new member on a forum has to receive at least 10 non answers before a legitimate one.

I'll say this, I have infact disassembled a lithium battery.
 
18650 cells have a high current discharge rate... There's a good reason you don't see your set up used.
 
So two batteries walk into a bar, and one says to the other " is this a power bar?" And the other says "yes I'm positive"

Ahh man, I could barely keep my self in my chair

Buy all seriousness aside what will happen if I try to power a 350 watt ebike with this battery tray?
18650 cells have a high current discharge rate... There's a good reason you don't see your set up used.
 
So, your cells are rated at 2C, which equates to 5.2 amps. The 16 awg copper wire is marginal, but should "work" for that current, at least for a while. You show a 9S1P configuration. 9 cells in series should yield 9x3.7V = 33.3V "nominal", but when fully charged, they will briefly yield 9x4.2V = 37.8V. Li-Ion discharge curves being what they are, most of the discharge life will be closer to the nominal voltage. Most 36V ebike battery packs are 10S, I believe.

I think the real question is, will this work for what? They won't propel a 36V ebike for long. If you want them to stay balanced, you'll need a battery management system (BMS) to keep the cell levels even, unless you have a low-voltage parallel charging scheme. So, what is the mission of your 36V ebike?
 
Thankyou four your reply wanders.

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So does the BMS demand current from each cell equally?

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-joke-
What did the charger say to the outlet?
 
The BMS hooks up to each parallel set of cells in the serial array. in your case, since you have a 9S1P array, it would need 10 connections (across each stage of the 9S array - it looks at every cell in the array). It monitors and balances voltages among the sets when charging (so that one set doesn't get over or undercharged), and it monitors voltages during discharge to avoid over-discharge. Typically, it can shut off the discharge when the voltage drops too low.
 
There is a reason that e-bike battery cells use soldered or spot welded nickel ribbon to carry the high current load. As mentioned by @harryS above, the gauge of the wire in the springs isn't heavy enough. They are also made from a steel alloy which isn't the best conductor. They will heat up under high current and lose their tension. That will compromise battery contact causing more heat. IMO, It's a fire waiting to happen.
 
My Main concern is building a battery with cells that:

-Aren't the correct capacity
-Don't have a many charge cycles in them
-have some funky characteristics in them like everything else I've tried to do

I've called Sony and asked about where I could buy real batteries. I ended up at some website that didn't stock the batteries and Sony sent me there.

Samsung and Panasonic's I knew weren't going to be easy to navigate






What is the best method of getting a good battery?
 
The bike did not go very fast

Also the cells dropped from 4.14v to 3.99 in maybe 200 meters

Thank you to everyone who replied in this thread and also those cared to take a look as well.
 
Oh and as to purchasing a new pack, I would like to build the most energy dense pack as possible as I have enough range with the current setup I have. Thank you gionni for refering me to Jenny mao.
 
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