The CM1051 series is a protection chip dedicated to 5 strings of lithium batteries or polymer batteries.
It has a built-in high-precision voltage detection circuit and a current detection circuit.
It can detect the voltage, charge and discharge current and temperature of each battery to achieve battery life.
Charge, over discharge, discharge over current, short circuit, charge over current,
over temperature and other protection functions, can adjust the delay of over charge,
over discharge, over current protection through external capacitor.

High-precision battery voltage detection function:
Overcharge detection voltage 3.50 V ~ 4.40 V (step 50 mV) Accuracy 25 mV
Overcharge hysteresis voltage 0.10 V accuracy 50 mV
Overdischarge detection voltage 2.00 V ~ 3.20 V accuracy  80 mV
Over-discharge hysteresis voltage 0 ~ 0.50V accuracy 100 mV

1 VCC positive power input terminal, battery 1 positive voltage connection terminal
2 VC1 battery 1 positive voltage connection terminal
3 VC2 battery 1 negative voltage, battery 2 positive voltage connection terminals
4 VC3 battery 2 negative voltage, battery 3 positive voltage connection terminal
5 VC4 The negative voltage of battery 3 and the positive voltage of battery 4 connection terminals
6 VC5 battery 4 negative voltage connection terminal, battery 5 positive voltage connection terminal
7 VSS chip ground, battery 5 negative voltage connection terminal
8 TOC Capacitor connection terminal for overcharge detection delay
9 TOD Capacitor connection terminal for overdischarge detection delay
10 TEC capacitor connection terminal for overcurrent detection delay
11 RTS connects to NTC for temperature detection
12 RTV is connected to the RTS terminal to adjust the temperature protection threshold
13 VINI overcurrent detection terminal
14 DO over discharge detection output terminal
15 CO overcharge detection output terminal
16 VM overcurrent protection lock, charger and load detection terminals