20s 72v 18650 25A Common Port BMS Li Ion EV Battery Bms Common Charge Discharge Port With Balance Function

PCM or PCB ( protection circuit module or board ) is the "heart" of Lithium battery pack. It will protect Lithium battery pack from overcharging, over-discharging and over-drain, therefore it is the must to have to avoid Lithium battery pack from explosion, fire and damage.

For low voltage lithium battery packs (<20 cells), you shall choose PCM with equilibrium function to keep each cell in balance and good service life. For high voltage Lithium battery pack (>20 cells), you shall consider advanced BMS ( battery manage system) to monitor each cell's performance to ensure battery's safer operation.

A battery management system (BMS) is any electronic system that manages a rechargeable battery (cell or battery pack), such as by monitoring its state, calculating secondary data, reporting that data, protecting the battery, controlling its environment, and / or balancing it. A BMS may monitor the state of the battery as represented by various items, such as:

Voltage: total voltage, or voltages of individual cells
Temperature: average temperature, or temperatures of individual cells
State of charge (SOC) or depth of discharge (DOD): to indicate the charge level of the battery
State of health (SOH), a variously-defined measurement of the overall condition of the battery
Current: current in or out of the battery

RFQ

1.What is the common port and separate port? what is the difference?
We take 13S 48V 15A BMS as an example, common port 15A means your charge cathode and discharge cathode are connected in the same point end(our P-), charge cathode and discharge cathode are used in the common connection
port, so the charge current and discharge current are the same 15A. while the separate port is separately connected by charge cathode (C-) and discharge cathode (P-), so the charge current and discharge current are different, discharge current 15A, charge current 8A.

2.What is the balance function?
The working principle and function are as followings, when your one cell voltage is upto alarm voltage(Li-ion upto 4.18V, LifePo4 upto (3.6V), then the cell Balance starts to work, balance resistance starts discharge with 35ma(when balance discharge starts to work, BMS will starts a little heat up, which is the normal reflection), the cell is in both charging and discharging status, and others which are not reached to alarm voltage(Li-ion 4.18V, LifePo4 3.6V)are only in charging status, no discharging, when the fast cell voltage is reached to alarm voltage (Li-ion 4.25V, LifePo4 3.75V) BMS starts off power protection, all the other cells are all in stop of charging, this process will enable your battery charging in balance current, and your battery voltage are in balance status, but when your cell voltage difference are in a big range, then balance can not be functionning well

3.The relationship between Battery capacity and BMS current?
There is no direct relationship between Battery capacity and BMS current, big capacity doesn`t mean a big battery, but rely on continue current, that is to say if your engine is powerful, your should choose high current of BMS, it is not relied on battery capacity.

4. What type of charger should I choose?
Lithium battery must choose specific charger, do not use Charger for Leadacid battery, for leadacid charger may have MOS with high pressure breakdown protection, which will not protect of BMS over charge. Life Po4 battery charger voltage=battery string No.X3.6V, while Li-ion battery charger voltage=Battery string No.X4.2V.

5. What current BMS should I choose ?
Take 10S 36V as an example: what current BMS you choose is relied on your E-bicycle Motor power and current limitation of controller. eg., choose 15A for below 350W, 20A for below 500W, 30A for below 800W, 60A for Below 1000W, higher than 1200W are contact with our service specialist for suggestions, one inall, continue current shall be higher than current limitation in Controller.

6. Whether my BMS damaged?
if you want to judge if the BMS is damaged, please take the folowing steps, to test if each cell voltage is the same with
voltmeter? if the cell voltage difference is over 1.0V, the fault is displayed that it cannot run far, no power supply at the
start range, short charge time, all these issues are almost caused by battery cells, if BMS damaged is displyed as no charge, no discharge, no discharge while the battery has voltage.