12V 400A EV BMS
For 4 Lithium LiFePO4 Battery Packs in Series (4S)
USA Stock!

Features:

• Top Quality (A-level) Protective Circuit IC
• Strong Load Ability, Constant Discharge Current 400A, High Voltage Resistance, Low Inner Resistance Power Mosfet
• IC itself has power balancing function. The circuit is simple and reliable.
• Extremely Low Power Consumption. The consumption of the whole device is less than 50uA.
• The PCB uses high anti-corrosion, high water resistance, and high impedance ESD conformal coating

Specifications:

Wiring Instructions

First, Preparation before installation

Make sure the batteries are of a good consistency, the voltage difference is no more than 0.05V, the inner resistance is no more than 5 milliohms, and the capacity difference is lower than 30mAh. Connect the batteries in parallel first and then in series. The better the battery consistency is, the higher the performance of the BMS.

Second, Wiring instructions

Attention: Please use our wires for our BMS. Don’t use other factories’ wires because they don’t match up with our BMS.

Step 1, B-(blue thick wire): Connect to battery pack total negative pole –

Step 2, Disconnect the wires for batteries from the BMS side.

Step 3, Connect the wires to batteries. Start from the thick black wire to total negative pole (B1-), then connect the 2^nd red thin wire to the 1^st battery positive pole (B1+) B2+, B3+, B4+ … till the last red thick wire.

Step 4, When you are finished connecting all the wires to each battery, don’t plug into the BMS directly. We suggest you use a multimeter to measure the voltage of two adjacent metal terminals (You can see the white connector with silver metal pins on the BMS). If the voltage is 3.0~4.2V (LiNCM), 2.0~3.6V (LiFePO4), 1.5~2.75V (LTO), then the wiring is correct.

Step 5, Ensure the wires are connected to the batteries correctly and the voltage is normal. Then you can plug the wires into the BMS.

Step 6, P-: Connect P-(black thick wire) to load – and charger –

(if you ordered “common port”).

Charger+ connect to C-(yellow wire) load+ connect to P-(black thick wire)

(if you ordered “separate port”).

Step 7, charger+ and load+ connect to battery+. Please use thick wire. 

Third, Measure the total voltage of the pack and the output voltage of the BMS. If the voltage is the same, it means the wiring is correct. You can use the BMS now. Otherwise please check the wiring again according to the tips above.

Frequently Asked Questions about the BMS/PCB:

1, Which current PCB should I use?

Take a 13S 48V pack as an example: Which PCB you should use depends on the power of your motor or the current limitation of your controller. Below 350W, you can use 16A. Below 500W, you can use 18A, Below 800W, you can use 35A, Below 1KW, you can use 60A. Above 1200W, the same. If you are not sure, please contact us.

2, Can I use a bigger size of PCB than is indicated?

Suppose you need 60A PCB but you chose 80A, that will work.

80A allows for a higher current. A bit higher price is the only drawback.

But if you choose 50A, it will be too small. So you can use a higher spec but not a lower one than it should be.

3, What kind of charger should I choose?

A Lithium Battery must be charged by a Lithium Battery Charger. You can’t charge it with a lead acid battery charger because the lead acid battery charger might damage the MOS pipe of the PCB.

4, if I have a PCB, do I need any balancers?

Yes if you add QNBBM balancers, that will be perfect.

The Main function of the PCB is to prevent batteries from over-charging over-discharging, over-heating etc.

With balancers added, the batteries lifespan will be longer and the capacity will get fully used.

5, How do I judge if my PCB is broken or not?

If you’d like to judge if the PCB is fine or not, please use a multi-meter and see if the voltage of each cell is close to one other or not. When the voltage difference is 1V, the battery will have this kind of performance: the driving distance will be short, it will be cut off when started, the charging time will be very short. Under such a situation, a battery is defective. When the PCB is broken, the battery can’t be discharged. When you measure the battery voltage, it will be normal.

Quantity discounts show in the “Shopping Pallet”.

We love to meet or beat any competitor’s price!

Contact us with questions

9am-5pm Monday-Friday (mountain time)

(801) 566-5678

or email

[email protected]

or through our Contact Us page