36 volt lithium battery build
 

Hi
I have a 2000 ezgo golf cart.Its 36 volt.What I want to do is build a lithium battery pack for it.
I have a bunch of K2 lfp26650e-3800-21 cells.
the cells have the following specs
capacity 3800mah
nominal v3.2
fully charged volts 3.65-4.1
discharged 2.5-2.0
continuous discharge 12amp
charge current 3.8amps
What Im looking for is the best cell configuration.And what brand bms.
I only drive it about 20 miles a week.
Any help would be great
Thanks

Re: 36 volt lithium battery build
 

You're going to need a lot of cells to do this. Well over 100 cells. Work out a config and I would not go less than 60 amp hours and 10S. For continuous discharge, you need at least 100 amps.

Re: 36 volt lithium battery build
 

I have 250 cells

Re: 36 volt lithium battery build
 

That's enough. You need to invest in a good spot welder to connect them. You also need to test and sort them to make sure you are building a good battery out of them.

Re: 36 volt lithium battery build
 

I bought a kweld and I have been checking all the cells.All good so far

Re: 36 volt lithium battery build
 

Great. Make some pix and post them here so we can see your progress.

Re: 36 volt lithium battery build
 

The kweld is excellent, I have one.

Are the cells new or used? If they're used, as Volt_Ampare said, test and sort, noting the capacity of each cell. When selecting the cells for each parallel string, try using cells that add up to the same total Ah rate for each parallel string.

Lithium cells connected in parallel behave like on larger cell, so you want each of the "larger cells" to be the same capacity.

there's a lot of info in the following thread in regard to building your own pack. It uses repurposed Nissan Leaf cells and is 48v but a lot of the info is relevant, BMS, protection etc.
https://www.buggiesgonewild.com/show...ht=nissan+leaf

Look through that and come back with any questions you may have.

Cheers
Pat.