Building 13S17P battery, need some criticism on layout

I'm planing on retiring by old 13S battery and replacing it with 13S17P of LG M29 cells. For now the pack will only be pulling 25A, maybe some day I will look into pushing 40A if range won't suffer much. Well above what the cells can do, but that's just half the story. The limiting factor is my layout and the odd number of parallel cells I have plenty of space for the battery, padding, controller and maybe even a charger(Eltek FlatpackS). Any tips are welcomed. I've ordered some 0.2x 8mm nickel strips for this project. 2 layers of Series connection should be enough.

Looks like you’re using loads of little round cells if you used one big triangular cell it would fit much better and take less time to make.


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The cell arrangement looks good. With that big of a battery pack and chemistry you could easily push 80 to 90 Amps. Are you planning on using a BMS? The leftover area limits the size of your controller and BMS. I assume you’ve taken that into account. If you ever want to upgrade to a more powerful controller you may need to mount it outside the triangle space. I’m not sure if 0.2 nickel strips are in overkill I’m sure somebody else will chime in.


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CrazyFrog please just go away.
The layout looks good. If you are planning on putting it into a triangle bag you may have problems getting it through the zippered opening. I built a similar one last year and ended up making it in two sections to go into the bag one at a time then plugged together with XT90 connectors.
It might be worthwhile to build a mock up using sections of 1/2" cpvc plastic pipe hot glued together to test fitiment in the bag and in the bike frame.

crazyfrog said:

Looks like you’re using loads of little round cells if you used one big triangular cell it would fit much better and take less time to make.

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Interesting. Could you link to such a product? What chemistry puts out such high voltage with just one cell? Never seen a triangular one. . .

Is crazy frog licker nuts or does he not know triangle cells are just 3 cells in parallel?


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I haven't heard that description before but yes Crazy Frog is likely a nut licker.

Cdub said:

The cell arrangement looks good. With that big of a battery pack and chemistry you could easily push 80 to 90 Amps. Are you planning on using a BMS? The leftover area limits the size of your controller and BMS. I assume you’ve taken that into account. If you ever want to upgrade to a more powerful controller you may need to mount it outside the triangle space. I’m not sure if 0.2 nickel strips are in overkill I’m sure somebody else will chime in.


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Click to expand...

Right now I'm running a 60A Bluetooth BMS at 20-30A. 80-90 Amps will probably never be achieved as I only need it for 20-30mph city commuting(long range).
In terms of space I've left enough space for an 18fet controller I have right now + some slack for the cables, but If I ever have the need to upgrade I'd go with 12 fet Nucular controller. That thing can output 5kW and takes half the space.

Majority of Series connections have 4 strips, but one will only have 3 due to awkward positioning... The 0.2mm nickel strip might need to be doubled up as from the acceptable current table they should only be used for 7-10A per strip. So if I will ever want to pull more than 30 Amps I'll need a second layer.

Hwy89 said:

CrazyFrog please just go away.
The layout looks good. If you are planning on putting it into a triangle bag you may have problems getting it through the zippered opening. I built a similar one last year and ended up making it in two sections to go into the bag one at a time then plugged together with XT90 connectors.
It might be worthwhile to build a mock up using sections of 1/2" cpvc plastic pipe hot glued together to test fitiment in the bag and in the bike frame.

Click to expand...

I will be ordering a custom ebike bag so hopefully gonna be able to negotiate an adjustment for this battery, but thank you for the heads up. Didn't think of that.

I have not seen that thread about nickel strips before. Makes me question the two battery packs I’ve built. I read somewhere, obviously on the Internet. .15×10 mm is good for around 50a. Perhaps that was max and not the efficiency range. Can’t seem to find where I read this. Not on endless sphere. It’s clear you’ve done your homework. My last battery pack was 13S, 4P with .15X10 pure nickel one layer spot welded with a home made welder. Double layered the BMS connection end cells. I regularly pull 40 amps with no problems but now I’m wondering what kind of heat soak I’m getting. I double shrink wrapped the pack and built a custom Aluminium box for it. 25R cells btw. I would recommend using Palight Between the large chunks of battery that you have in bold on your drawing. Palight is a PVC foam board that can be molded with a little heat and hardened when cooled easy to cut and shape. Works great as a battery cover as well. It’s obviously non conducive.


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Hwy89 said:

CrazyFrog please just go away.
The layout looks good. If you are planning on putting it into a triangle bag you may have problems getting it through the zippered opening. I built a similar one last year and ended up making it in two sections to go into the bag one at a time then plugged together with XT90 connectors.
It might be worthwhile to build a mock up using sections of 1/2" cpvc plastic pipe hot glued together to test fitiment in the bag and in the bike frame.

Click to expand...

Man asked for criticism not constructive criticism don’t be so stiff.


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