My new battery for my bike.

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So I wanted a new battery basically just because I could....sounds goofy I know but my last pack of Koinions still could pump out 200 amps but I just wanted something that could hold a charge longer. I had a 20s15p V3 Koinion pack 1600mah for a total of 23 amps. I built a 20s15p Samsung 30Q pack 3000mah for a total of 45 amps. First ride today with the new pack I rode hard and fast with some peddling. Started out at 4.1 v per cell at 82 volts and went 19 miles. Finished with 3.9 v or 78 volts after pulling 200 amps many, many times! Rode it for the most part like a motorcycle today.....not super fast but always quick to speed.

Bought all the cells and nickel from nkon https://ru.nkon.nl/ and have nothing but great things to say about the whole purchase. Like my previous build I followed/copied madin88’s battery building ideas. Used my home built 800 watt second capacitor discharge welder with glidcop electrodes that produced flawless welds.

Clean area, 25mm x .15mm nickel, copper strips for even current flow, all cleaned with alcohol after prep, 8 gauge super flexible wire and huge 8mm anti spark connectors. The finished pack was wrapped in 2 layers of packing foam and then tightly wrapped with duct tape as I think it’s the most durable battery covering you can get. Shrink wrap has a tendency to crack at edges and sometimes mid pack.

Fun build and should last for many, many years.

Tom

I would have done it so you have wires (all the same length) coming off several spots off your first and last 1P string of each block, so it evens out the current flow. Perhaps to reduce the bulk in wiring, instead of every second one (as shown) do every 4th. If you think about the electron having to travel much further in the top section then the bottom section, that is what I would want to avoid. Your sense/balance wires are good to go.

Each parallel string makes 15A and you have 8P and 4P and 8P, so your 8's are 120A and your 4 is 60A. Divided by how many "collector arms" are coming off each block.


But overall, I'd say your build is looking good.

You do see the 2 strips of 10 gauge copper on each positive and negative nickel strips don’t you? Soldered to the nickel in between each of the cells with silver solder?

It’s my opinion that running multiple wires to many spots vs solid copper wire soldered to each spot is either the same or better with the 2-10 gauge wires soldered in between each cell.

As far as the 8s ad 4s bricks I had thought of the less amperage the single 4s will have to carry. I do believe adding 2 more connectors, all the extra copper, solder would have added more resistance and wrapping them separately probably would not fit in the compartment.

Tom

Nice work Tom

Nice build, would be nice to know how much the cells were, how much and what kind of shipping and how long it took to arrive from Russia.

They came from the Netherlands and took about 3 1/2 to 4 weeks to get here. Total cost was right under $1300 shipped to my door for 305 cells, a shit load of nickel and a shit load of insulation paper.

The pack is good for a speculated 100 miles at 20 mph. I was able to go 35 miles and used 34% of my pack. I also did 25 mile trip mostly 25 but up to 55 mph all throttle and used 60% which makes me think I could do 40 to 50 miles at 40 mph.

Two thumbs up!

Tom

Nice work. I think the bus bars look good. If you wanted to be really picky about it, you could calculate the voltage drop across the bus at full current. I bet it's not enough to be a concern.