A question for any battery builders, DIY 72v 48ah 20S16P build.

Hello everyone,

I'm going to be building my first battery soon. I know there are some very intelligent minds on here that have had a lot more battery building experience than I have.

This is the plan, I'm going for a 20S16P configuration, 320 total cells with a BMS. 72v 48ah.

I would really appreciate if someone could tell me how to connect the cells in the correct order as I don't want to blow anything (or myself) up.

Thanks in advance.

Pictures of my planned layout to follow....

Would doing it this way work or am I way off with my thinking?

I think I can get away with 20S16P

Black are negative
Red are positive
Current flow is green line

no cell holders? what will keep it together

I'm going with the hot glue method.

Or I might 3d print these cell holders that I designed.

This is what I am thinking about how to connect the cells together with nickel strips...



Can anybody see any potential problems with this?

Take a look at this thread for the topic of "current sharing" : https://endless-sphere.com/forums/viewtopic.php?f=14&t=84412

I'm not sure how much current you plan on drawing from the pack but 16P has potential for some pretty high current. Some of the series connections only have 3 cells to share the current of 16P.

I think I understand what your saying.

I need to make it so there are more than 3 adjacent cells next to each bank, more cells sharing the connection the better. I can see where there are only 3 cells next to the next bank.

I can go back to the drawing board & try to tweak my layout but apart from that, am I not far off building the battery correctly?

I appreciate your advice, thank you.

Everyday is a school day, especially when your a noob like me.

I've had a shuffle around with the cell layout to remove the areas where the connection was only on 3 cells.

So I am attempting to build my first battery. A 20S16P configuration, 320 18650 cells with a BMS. 72v 48ah.

This is my final design with all the connections that I will be making. Hopefully it doesn't blow up.

Parallel connections


Series connections Side A


Series connections Side B

Don't get me wrong, I am trying to help:
But why are you using this cells (I suppose 18650) for this pack?
I know that Teslamotors does that. But now it is not the best, cheapest or easiest way to create a battery pack this size.
You have plenty of different larger prismatic cells or larger cylindrical cells now to choose from with very reasonable prices.

Tesla did that way because several reason at its time, and keep on doing it because they can not throw away thousands of millions of dollars on its manufacturing development. (But they already have changed to a much larger cell)

But knowing the actual big availability of prismatic/cylindrical cells it is an error to follow that path.
Why: With larger cells the pack will be cheaper, much easier to build and provably more reliable.

I was looking at alternative larger cells that were meant for an electric race car but due to the size of the cells, I was struggling to fit in the amount that I require, purely because the individual cells were so big & I was leaving a lot of space in my frame. The battery would be either too big or not big enough.

Using 18650's I can make the battery to the perfect odd shaped design & size of my frame to maximise the space that I have available.