Battery packs - cycle life

EFOIL.builders Electronics (ESC, remote, batteries)
#1

I’d be interested in hearing from other people how their various batteries are lasting after extended use.

I have around 150 cycles on a molicel p42a 13s6p pack, and it’s still offering fairly comparable run times to when new. The p42a seems to get 500 cycles to 80% capacity, in testing on the forums.

My latest pack is running with the Samsung 40T3, which is rated at 600 cycles to 80%, (around double the cycle count of the original 40T).

Samsung 30Q seems to be popular in the commercial efoil batteries, with a cycle count of 300 to hit 80% capacity. What sort of durability are people seeing on these packs in the real world?

How are lipo packs are holding up after 100+ cycles, do they get puffy with 80A+ running through them?

I considered going to a Samsung 50E on my latest 13s8p build, for the extra capacity and long cycle life. I’m using these on my ebike, but I suspect they’d sag too much under 80A load for waterstarts (10A per cell). Particularly as the voltage gets lower and the required current draw is higher. Maybe these would be suitable in a bigger 10p configuration (too heavy for a tow boogie)?

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#2

I think most of the efoils don’t get used enough for the cycle life to matter so much. 5 months/20 weeks a year, twice a week and 300 cycles gives a lifespan of 7.5 years

I would not use 30Q anyway due to the limited cycle life, if i build a pack with cylindrical cells i’d either use whatever name brand cell i could find discounted or go for the top cells like molicel p42. If i wanted to build quickly i’d buy some EV battery cells like from a a VW e-golf or id3

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#3

We are using 2.1kW VW EV battery’s, and they work great.

Only problem with the EV battery’s is that they are 12cm high, so you need to build a board that is thicker than 12cm.

#4

Just curious, any pict of them + item dimensions ? Can’t they be mounted flat to decrease the apparent thickness ?

#5

Same for me, module height (and smallest dimension) is 120mm so i have a 150mm board

They are really powerful, i’ve used these cells on my ebike at 300A.

Some pics here:https://www.power-and-storage.de/shop/Samsung-SDI-PowerBlock-12S-48-1-6-48V-1-62-kWh-p266060893

image
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#6

Same here. (2 times)

The one in the picture below is covered in silicone gel.

batt
batt1920×3410 769 KB

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#7

I’m using the 30Q cells in a 16s 14p config, so far 100ish cycles, still at full power and full capacity.
Charge up to 4.18v per cell and discharge to 3.3v per cell, charge with 1.4A per cell and regularly pull 100ish from the pack. Hopefully she keeps giving a while longer!

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