Battery Layout Help

[jcnsdad]

I am at my wits end trying to find out the best way to lay this battery pack out. I have read so many instructions and looked at a lot of photos with no clear way of laying it out. I am trying to make a 52v 20 AH pack with 91 cells using a polly PD-9 Box. the cells are recovered from backup packs with minimal use. the specs are:
Model: LGABF1L1865 (INR18650F1L)
Capacity: 3350mAh Rated
Voltage: 3.63V Nominal
Charging: 4.20V Maximum 975mA Standard 1625mA Maximum
​
The bike motor is an Janopay 1,000WAH 48v-52v I have attached a layout that I put into my battery layout not sure its correct or how to connect what to what.the battery holder is a Polly DP-9 Down Tube max load of 91
If anyone could help me with the layout I would appreciate it I'm beginning to think I just should have bought an off the shelf Pack. I would like to just do the pulling of the nickel strips only once. If more info is needed just let me know.

Thank you

 

[beemac]

I am at my wits end trying to find out the best way to lay this battery pack out. I have read so many instructions and looked at a lot of photos with no clear way of laying it out. I am trying to make a 52v 20 AH pack with 91 cells using a polly PD-9 Box. the cells are recovered from backup packs with minimal use. the specs are:
Model: LGABF1L1865 (INR18650F1L)
Capacity: 3350mAh Rated
Voltage: 3.63V Nominal
Charging: 4.20V Maximum 975mA Standard 1625mA Maximum
​
The bike motor is an Janopay 1,000WAH 48v-52v I have attached a layout that I put into my battery layout not sure its correct or how to connect what to what.the battery holder is a Polly DP-9 Down Tube max load of 91
If anyone could help me with the layout I would appreciate it I'm beginning to think I just should have bought an off the shelf Pack. I would like to just do the pulling of the nickel strips only once. If more info is needed just let me know.

Thank you

Can't see any attachment but first off you need to decide on the number of cells - you don't need all 91 to make a 52v 20Ah pack - using your cells that's 14s6p so only 84 cells. A 48v 23Ah pack would use all 91 cells - 13s7p.

I used this site when I built my first pack:

https://www.ebikeschool.com/how-to-build-a-diy-electric-bicycle-lithium-battery-from-18650-cells/

Really good info

Only thing I'd add to the info on that page - is use split nickel strips. Not sure if I'm just useless at spot welding (probably) - but putting a split down the strip really makes it soooo much easier - I put stacks of cut strips in a vice and used a dremel disc to cut grooves in them - oh actually thinking back I tried that and just vapourised many little cutting discs so just used a hacksaw instead - anyway - or you can buy them ready split which is what I'd probably do in future.

 

[docw009]

I looked at the datasheet on the LG INR18650F1L. It wouldn't have been my choice for an ebike cell. Has good capacity at 3.3AHm but max current is low at 4.9A, and the AC impedance of 70 milliohms is pretty mediocre. Good ebike cells are under 25 milliohms when new. Your cells will show larger voltage sag at higher currents. How many amps is your ebike controller?

If you're going for a 52 volt battery, that is fourteen series groups. If you have a cell holder with 91 spaces, the biggest battery you can make is an 84 cell 14S-6P. That's fourteen banks of cells, each with six cells in parallel. This should be clear to you.

You didn't attach your proposed cell layout. The DP9 will allow a pretty nice 14S-6P layout, What does your proposed layout look like? What BMS did you buy? Did the case come with precut metal strips or any strips at all?

 

[v85]

There are already nickel strips for this case with 18650 cells: https://a.aliexpress.com/_mLHWChe

But you must know how to arange serial groups of 6 cells parallel

 

[chuyskywalker]

There are already nickel strips for this case with 18650 cells: https://a.aliexpress.com/_mLHWChe

But you must know how to arange serial groups of 6 cells parallel

Getting these is so worth your time; saves some much work cutting out the nickel by hand.

 

[jcnsdad]

Thank you for all of the great info. That's what I ended up doing was to follow the DP-9 layout (14s6P). I just ended up cutting the strips by hand. It would've been worth having them pre cut but it seems when I order from aliexpress it takes a month of sundays to receive anything. I was trying to get this done before the snow flies and I have to put it away until spring. I haven't picked out a BMS yet if anyone has any suggestions im all ears. Again thanks for all of your help.