Question Question About Battery Setup

[Beck]

I'm starting work on a portable PS2. I've built a portable N64 and a few portable Raspberry Pis in the past, but have always used power banks for my portables. This will be the first time I'm not and I want to clarify some things about my setup to make sure it's safe.

I've read the battery guide several times but I want to be extra sure my setup is good as I'm really concerned with safety. I'll be using two 18650s wired in series for 7.4V to power the system. Specifically these cells:

Samsung 35E 18650 3500mAh 8A Battery

Samsung 35E 18650 3500mAh 8A Battery The Samsung 35E battery is a high-performance power source, offering an impressive 3500mAh capacity and a discharge rate of up to 8 amps. Whether you're using it in laptops, electric vehicles, or other high-demand devices, this battery provides extended run...

imrbatteries.com

For the BMS, I'll be using this one I've seen mentioned on the forums:

Intelligent Balance Charging Protection Board 2S Packs 18650 lithium Satellite | eBay

4, short circuit protection function: When Vout + and GND short-circuit protection circuit will quickly action within 5-50uS, cut off access, short-circuit protection. The protective plate is used in Japan MITSUMI original battery protection chip.

www.ebay.com

If I'm understanding, I should be able to use any old power supply as long as it's between the input voltage range specified on the board (9v-18v), correct? I don't need a smart charger? I know this is all in the guide and I'm probably being annoyingly cautious, but I'm very concerned with battery safety and want to make sure I get this right before I wire everything up since I haven't done this before. Thanks in advance.

 

[Stitches]

You are correct, the "Red Board" BMS (they used to be red) will accept any dumb input voltage within its advertised range to charge the cells. I have personally used a 9V3A supply with an older revision of it and it worked great. Just be aware that the max charging rate of that BMS is only 1 Amp, so it will take around 8-10 hours to charge 4 of those cells.

It also has a safety feature where you are required to connect a charging current after first connecting the cells to enable output from the BMS. This only needs to be done when cells are disconnected or added to the BMS.

 

[Beck]

You are correct, the "Red Board" BMS (they used to be red) will accept any dumb input voltage within its advertised range to charge the cells. I have personally used a 9V3A supply with an older revision of it and it worked great. Just be aware that the max charging rate of that BMS is only 1 Amp, so it will take around 8-10 hours to charge 4 of those cells.

It also has a safety feature where you are required to connect a charging current after first connecting the cells to enable output from the BMS. This only needs to be done when cells are disconnected or added to the BMS.

Awesome, thank you