1S 3.7V 18650 PCB board and 4.2V cylindrical protection circuit with 4A constant working current for single li-ion cell


This is The PCB for single 18650 cell PCB Board with 4A constant discharge current
This is The PCB for 1S 3.7V or (4.2v) lithium ion 18650 battery .

1) Over-charge protection voltage with single cell :4.25V??0.025V

2) Over-discharge protection voltage with single cell :2.40??0.1V

3) Over-current protection :7A??1.4A

4??Constant working current : 4A

5) Size :17.5*1.8mm
6) Functions : Over-charge protection ,over-discharge protection ,over-current protection ,short circuit protection .

VoltageCharging voltageDC 4.2V CC/CV
Balance voltage with single cell
CurrentBalance current for single cell
Current consumption with single cellless than 10 uA
constant charge current 4A
constant Discharge current 4A
Over-charge Protection Over-charge detection votlage4.25V??0.025V
Over-charge detection delay times 0.7~1.3S
Over-charge release voltage 4.1?? 0.025V
Over-Discharge Protection Over-Discharge detection votlage2.4V??0.01V
Over-Discharge detection delay times 80~167mS
Over-DIcharge release voltage 3.0?? 0.01V
Over-Current Protection Over-Current detection votlage0.62V
Over-Current detection current 5-7A
Over-Current detection delay time 8~16mS
Over-Current release conditionLoad off
Short circuit protection Detection conditionExternal short
Release conditionLoad off
TemperatureOperating temperature range-40~85 degree
Storage temperature range-40~125 degree
Dimension (L*W*T) 17.5*1.8* mm

Photo border


1)Do not apply the PCB which beyonds the specified criterias as above :

2)Sometime , the battery may not discharge when connected this PCB , please connect it to the charge and it can recover to the normal

status .

3)The PCB may not work normarly When Mixing cells which were over-discharged or over-charged ,

4) Do not shock this PCB with big static even though the PCB has been designed with anti-stastic protection function.

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should afford the extra freight cost by express delivery .

As post by air ,usually it takes around 20-60 days ,please notice it and do not open the disputes easily before reaching the

contact with us ,we will try our best to solve the problem with our joint efforts .

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for buyers’ mistake or wrong handling, our product must be maintained in proper way. If Item is defective and not working

on arrival, please report the item to us within 7 days of receiving the defective product so we can issue a RMA.

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be tested and if found defective, the buyer will be shipped a new replacement unit immediately. In the event that a suitable

replacement is not available a refund will be issued.

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