Question 1

If a single cell drops below 2.3V will the entire battery pack be disconnected? It appears that all three cells need to drop below 2.3V.

Accepted Answer

Calling this tiny board "BMS" is overkill, This is more of a simple "Battery Protection board" with little bit of so called "BMS" thingy. This BMS won't cut on discharge until at least one "cell-group" has dropped to a dangerously low voltage.. Since you see the arrangement is 3S and with 5 x 18650 in parallel, one of such cell-group developing an internal fault and dropping to a dangerous low level of 2.3 while the rest of the cells in the 3S configuration having more than 4.0 is very rare and if that ever happens, it better that the BMS disconnects that cell-group to save the other two groups.

To answer your question: - Yes! if single cell drops below 2.3v it does have a potential for the entire battery pack to be disconnected from the output terminal by design.

Question 2

One you build the battery, i assume you need a 12v dc charger. anyone have any reccomendations for chargers?

Accepted Answer

find something at 12.6v - there is a company called talentcell on amazon that sells some already put together batteries using 3s 18650 cells at various parallel configs to give different capacity. They do sell their 12.6v chargers separately - but keep in mind they are designed for 3s2p or 3s3p levels of setup - i think 1 or 2 amp - so depending on how big your build is - these may not work for you. I have in the past gone with 12.6 volts and used 1 amp for every parallel set of  cells. so for a 3s5p battery i had a 12.6v 5a charger - lots of those on here too.

Question 3

When using a 12v power supply to charge the battery, will the BMS automatically shut off, or can it be overcharged?

Accepted Answer

For this item the max voltage that should be put into it for standard max voltage 4.2v 18650 batteries is 12.6v (4.2v x 3s). Any more than that and you risk overcharging (damaging) your batteries. For the longest life for the batteries over time 12v should be most optimal (ends up being about 8-10% under max capacity of most batteries).

Question 4

What thermocouple is needed for these boards?

Accepted Answer

There is no capability for temp monitoring on this board that I have seen.

ASIN	B07JMY631D
Best Sellers Rank	#334,967 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #1,439 in Power Converters
Brand	daier
Color	green black
Customer Reviews	4.4 4.4 out of 5 stars (716)
Input Voltage	3.7 volts
Item Weight	12 g
Manufacturer	daier
Mfr Part Number	Z370*2
Model Number	Z370*2
Number of Items	2
Number of Packs	2
Output Voltage	4.35 volts_of_direct_current
Plug Type	2 Pin
Power Source	battery
Unit Count	2 Count

2Pcs 3S 11.1V 12.6V 25A W/Balance 18650 Li ion Lithium Battery PCB Protection Board

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