Dinky Battery 13S-1P


1 MW
Aug 2, 2015
Illinois, Not far from Wayne's World.
I purchased the Battery Hookup Molicell M42's last month. Tested one at 4.2Ah on my Littokala tester with a 500ma load. Made a 13S-1P brick to see how they worked. Makes for a nice compact battery. My load tester says it's 3.8AH with a 3A load. I was disappointed with that, hoping it would do better than 90%. On the other hamd, 26 bucks for the cells, $16 for the BMS, $5 for the rest, it's OK.


What to power with this tiny battery? I tried my Tong Sheng TSDZ2 conversion. It has the OSF formware, but still only pulls 11.8A max. Typically uses 6-8 wh/mile,

The road test got me 25 miles before the battery died. I had used 3AH to reach 22 miles, suggesting a real world life of 3.5AH.

I also did some other tests. I spot welded a short length of 8) mm .15mm nickel* to a P42 cell, about enough to do a series connect from one cell to another. I put this on my load tester and eventually got to pulling 20 amps thru it.

IMG_5523-1.JPG IMG_5520-1.JPG

The P42, nickel, and wires stayed cool for the tests. I put my IC resistance meter on the metal strip. It use two point probes and is pretty precise for small voltages.

I'm looking at 22 millivolts at 20A. If that's accurate, then with 26 of these series tabs, that's .57 volts in losses at 20A. I'll probably be in the 4-5 A range, so the resistive drop is small at 100 mv. For the kind of packs I make, which are mostly for 20A bike controllers. I think the 10 mm wide .15mm thick nickel will be enough. It's about the limit of my spot welder anyway.

*EDIT: I originally wrote 10 mm nickel, but re-measured it, and it was 8 mm nickel.

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Seems to me like it puts a critical perspective on their 45A/cell claim. Is that 45A at nominal-ish voltage, or 45A at 1V?

Not that it matters much, because it would be a rare cell tab that could carry 45A without turning into an incandescent filament, or else destroying the cell in the process of being welded on.