09-30-2025, 11:08 AM
3S lithium ion at 3.6v nominal voltage range of 12.6 to 7.5v make such an arrangement a poor substitute for lead acid's range of 10.5- 15v+, and 4S is just too much at 10v- 16.8v
At no point should 3s lithium ion ever be exposed to charging voltages above 12.6v.
4S Lifepo4 has a much better range for lead acid substitution at 10-14.6v.
Lesser energy density but better safety than nickel maganese colbalt.
This will be a 20AH 11.1v nominal battery made with lightly used Samsung 50E cells.
These cell rated at at 9.8 amps CDR, and 4900mah minimum capacity, y no means impressive figures in tohe current marketplace, but cannot argue with free.
I am using a 6$ 40 amp BMS with balancing function.
I am trying to decide how I want to attach it to the 3s4p 50E..
These BMS usually cut power when the lowest P group touches 2.8v, but there s so little energy below this voltage that is fine with me.
Powering leds, their max brightness will be limited at 11.1v and below, as will maximum fan speed, but is not a huge concern as I rarely run either at max output anyway.
These 12 21700 cells are a fraction of the weight and size of my 22AH AGM battery. I could fit it in my cargo short's pocket if required.
My 3s1p EVE 40PL(tablesz power cell) will be getting same 40 amp BMS. These cells can output 40amps.continuous without overheating, and can handle 70amos, limit temperature to below 80C.
Mooch has tested them at 100amps continuous, and they handle it far better than all but about 4 of the very best power cells.
I will likely add a heatsink to the BMS mosfets. They look to be poorly matched, and that means their resistances will vary, with some taking far more.of the load than others, getting far hotter.
Ill likely never use either 3s 40amp BMS near their limits, but one needs to know those limits and stay under them, or only flirt with them briefly.
At no point should 3s lithium ion ever be exposed to charging voltages above 12.6v.
4S Lifepo4 has a much better range for lead acid substitution at 10-14.6v.
Lesser energy density but better safety than nickel maganese colbalt.
This will be a 20AH 11.1v nominal battery made with lightly used Samsung 50E cells.
These cell rated at at 9.8 amps CDR, and 4900mah minimum capacity, y no means impressive figures in tohe current marketplace, but cannot argue with free.
I am using a 6$ 40 amp BMS with balancing function.
I am trying to decide how I want to attach it to the 3s4p 50E..
These BMS usually cut power when the lowest P group touches 2.8v, but there s so little energy below this voltage that is fine with me.
Powering leds, their max brightness will be limited at 11.1v and below, as will maximum fan speed, but is not a huge concern as I rarely run either at max output anyway.
These 12 21700 cells are a fraction of the weight and size of my 22AH AGM battery. I could fit it in my cargo short's pocket if required.
My 3s1p EVE 40PL(tablesz power cell) will be getting same 40 amp BMS. These cells can output 40amps.continuous without overheating, and can handle 70amos, limit temperature to below 80C.
Mooch has tested them at 100amps continuous, and they handle it far better than all but about 4 of the very best power cells.
I will likely add a heatsink to the BMS mosfets. They look to be poorly matched, and that means their resistances will vary, with some taking far more.of the load than others, getting far hotter.
Ill likely never use either 3s 40amp BMS near their limits, but one needs to know those limits and stay under them, or only flirt with them briefly.
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