Home › Parts › Charging & BMS › 4S LiFePO4 BMS 20 A

4S LiFePO4 BMS 20 A

Charging & BMS · 12 V 20 A

Daly 4S 20 A LiFePO4 common-port · 4S LiFePO4 · 20 A continuous, trips at about 60 A (1 ms), short circuit about 120 A (250 µs) · over-charge 3.75 V/cell (15.00 V pack), over-discharge 2.5 V/cell (10.0 V pack) · balancing 30 mA from 3.5 V

4S LiFePO4 BMS 20 A on the simulator's bench

Try it on the benchThe lab drops it on an empty bench and opens its datasheet card.

Typical part: 4S LiFePO4 BMS 20 A — modelled on Daly 4S 20 A LiFePO4 common-port

Pins

Ratings and limits

ProtectionDaly standard LiFePO4 BMS
Cells4S LiFePO4
Over-charge3.75 V per cell after 1 s · release 3.65 V
Over-discharge2.5 V per cell after 1 s · release: connect a charger (or the cells recover above 2.7 V)
Discharge current20 A continuous · over-current trip about 60 A after 1 ms
Short circuitabout 120 A · 250 µs · release: remove the load
MOSFET resistance7.5 mΩ (150 mV and 3 W at 20 A)
Balancingpassive, 30 mA from 3.5 V
Temperature protectionnone: above its continuous rating it heats, and its MOSFETs can fail shorted

How to use it

Wire B− to the pack’s negative end, B1…B3 to each junction between cells in order, B+ to the positive end. The load and charger go on P+ and P−: the board switches the negative side with back-to-back MOSFETs.

More in charging & bms