Charging port for fast charging

What is good a charging port for 10S4P battery with 30Q cells? Charging this pack at 1/2 C rate means 6 Amps, and 1C rate 12 Amp. So, theoretically, it should be Ok to charge is at 12 Amp. My BMS can handle charging at 10 Amp.

I see that many people use 2.1mm x 5.5 mm charging jacks. But these jacks are rated for 5 amps and 12 (or 24) Volts. So I guess, it may not a good idea to use them for 42 Volt charger at 10 Amp.

Is it still Ok to use them for 10 Amps? Or is it a better idea to always stay below 5 amp for charging? (Safer, better battery life, etc.)

As an alternative to 2.1 mm x 5.5 mm jack, I am considering using two banana plugs as a charge port. This is definitely going to handle higher current. But this method is not idiot-proof. I don’t know what is going to happen if somebody accidentally switch polarity. (Lot of sparkles? Explosion? Fire and fury?)

Does anybody use banana plugs as a charging port?

you could use an xt60 for charging. I recommend just sticking with 5.5x2.1 and charging at 4a tops. The slower the charger the better it is for your cell’s cycle life.

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I am currently using an XT60 for charging with a balance charger. But I need to open the enclosure to access it. I guess I’ll use 5.5x2.1 port for normal charging at 4amp, as you recommend. In case if I need to charge the battery faster, I can open the enclosure and use an XT60 connector inside. Thanks for the advice.

I checked the specs. With 4 cells in parallel, 6 amps is the normal charging current. What Jinra say is fine. You won’t find many chargers at 5 or 6 amps at 42V for cheap. Disregard using the C value with lithium-ion cells as manufacturers do not rely on using ambiguous units. The specs provided by Samsung say a single 30Q cell can be fast charged at 4 amps for 70 minutes. Better to charge slower and not to the full 42V to extend battery life beyond 300 cycles.

I have an iCharger balance charger. It can easily do 6 amps or higher. Do you think that a 5.5x2.1 jack would be Ok for charging at 6 amps, even though it is a bit above its rating?

For safety, stay at 5 amps or less with the 5.5x2.1 jack as specified by the manufacturer. The worst that can happen is heat damaging the jack from too much current.

Thanks. This makes sense.

Out of curiosity, I’ve checked the specs of Evolve “fast charger”. It is 42 Volts and 4 Amps. So I guess charging at 4 amps is already considered to be fast.