2. BMS1820 Pinouts and Descriptions

BMS1820 measures up to 18 cells on connector 1 and drives the slave modules over the isolated daisy chain (RJ45 connector 14 or 4-pin connector 15). Power and the button come in on connectors 10 and 11, the current sensor and the temperature sensors on connectors 2 and 3, the communication ports on connectors 4 and 5, and the inputs and outputs on connectors 6, 12 and 13. Arrange the cables with the pinouts below; a number in the figures opens the table of that connector.

Danger

Check every connection and cable before you plug a connector into the BMS1820.

Fig.2.1: BMS1820, Board Pinout (TOP)

BMS1820, Board Pinout (TOP)

Fig.2.2: BMS1820, Board Pinout (LEFT)

BMS1820, Board Pinout (LEFT)

Fig.2.3: BMS1820, Board Pinout (FRONT)

BMS1820, Board Pinout (FRONT)

Fig.2.4: BMS1820, Board Pinout (BACK)

BMS1820, Board Pinout (BACK)

Table.2.1: Connector No#1 Descriptions

Connector No. Pin No. Description (see Fig.2.1 and Fig.2.2)
1 1, 2 Bottom of the battery string, 1st cell's negative tab (C1-)
1 3 3rd cell's positive tab (C3+)
1 4 5th cell's positive tab (C5+)
1 5 7th cell's positive tab (C7+)
1 6 9th cell's positive tab (C9+)
1 7 11th cell's positive tab (C11+)
1 8 13th cell's positive tab (C13+)
1 9 15th cell's positive tab (C15+)
1 10 17th cell's positive tab (C17+)
1 11 1st cell's positive tab (C1+)
1 12 2nd cell's positive tab (C2+)
1 13 4th cell's positive tab (C4+)
1 14 6th cell's positive tab (C6+)
1 15 8th cell's positive tab (C8+)
1 16 10th cell's positive tab (C10+)
1 17 12th cell's positive tab (C12+)
1 18 14th cell's positive tab (C14+)
1 19 16th cell's positive tab (C16+)
1 20 Top of the battery string, 18th cell's positive tab (C18+)

Table.2.2: Connector No#2 Descriptions

Connector No. Pin No. Description (see Fig.2.1 and Fig.2.3)
2 - Current Sensor Connector
2 1 Current Sensor CH1 Sense Input
2 2 Current Sensor CH2 Sense Input
2 3 5V Output for Current Sensor Power
2 4 12V Output
2 5 FET Temperature Sensor Input (NTC), not used by the current firmware
2 6 GND for Current Sensor Power

Table.2.3: Connector No#3 Descriptions

Connector No. Pin No. Description (see Fig.2.1 and Fig.2.3)
3 1, 2, 3, 4, 5 Ground (GND) of the temperature sensors
3 6 External Temperature Sensor No.5 (NTC5)
3 7 External Temperature Sensor No.4 (NTC4)
3 8 External Temperature Sensor No.3 (NTC3)
3 9 External Temperature Sensor No.2 (NTC2)
3 10 External Temperature Sensor No.1 (NTC1)

Table.2.4: Connector No#4 Descriptions

Connector No. Pin No. Description (see Fig.2.1 and Fig.2.3)
4 1 RS232 No.0 Transmit Data (Service Port)
4 2 RS485 B Pin
4 3 ISO- GND
4 4 RS232 No.0 Receive Data (Service Port)
4 5 RS485 A Pin
4 6 ISO-5V Output

Table.2.5: Connector No#5 Descriptions

Connector No. Pin No. Description (see Fig.2.1 and Fig.2.3)
5 1 ISO- GND
5 2 CAN 2.0b CH1 Low Pin (CAN L)
5 3 ISO-5V Output
5 4 CAN 2.0b CH1 High Pin (CAN H)

Table.2.6: Connector No#6 Descriptions

Connector No. Pin No. Description (see Fig.2.1 and Fig.2.3)
6 1, 2, 3, 4, 5 ISO GND
6 6 Isolated Input 1 (LiMon INPUT 1)
6 7 Isolated Input 2 (LiMon INPUT 2)
6 8 Isolated Output 2 (LiMon OUT 6)
6 9 Isolated Output 1 (LiMon OUT 5)
6 10 Isolated Input 3 (LiMon INPUT 3)

Table.2.7: Connector No#9 Descriptions

Connector No. Pin No. Description (see Fig.2.1)
9 - Port for LiBat Extension Board

Table.2.8: Connector No#10 Descriptions

Connector No. Pin No. Description (see Fig.2.1 and Fig.2.4)
10 1, 2 Board VIN+ (Board Main Power)
10 3 External Button Input, a push-button to VIN+ (pin 2) starts the BMS
10 4 Board GND (Board Main Power)

Table.2.9: Connector No#11 Descriptions

Connector No. Pin No. Description (see Fig.2.1 and Fig.2.4)
11 1 Board VIN+ Output
11 2 External LED- Output (LED GND)
11 3 Board GND
11 4 External Button Input, a push-button to VIN+ (pin 1) starts the BMS
11 5 External LED+ Output
11 6 +12V Supply Input (12Vin), never together with VIN+ on connector 10

Table.2.10: Connector No#12 Descriptions

Connector No. Pin No. Description (see Fig.2.1 and Fig.2.4)
12 - High-Side Switch Outputs, for mini relays, not for contactor coils
12 1, 2, 3, 4, 5 GND
12 6 High-Side Switch Output (LiMon OUT 4)
12 7 High-Side Switch Output (LiMon OUT 3)
12 8 High-Side Switch Output (LiMon OUT 2)
12 9 High-Side Switch Output (LiMon OUT 1)
12 10 External Supply Input of the High-Side Switches (Vext)

Table.2.11: Connector No#13 Descriptions

Connector No. Pin No. Description (see Fig.2.1 and Fig.2.4)
13 1, 2 Relay Common Pin (LiMon OUT 7)
13 3 Relay Normally Open Pin (LiMon OUT 7)
13 4 Relay Normally Closed Pin (LiMon OUT 7)

Table.2.12: Connector No#14, #15 Descriptions

Connector No. Pin No. Description (see Fig.2.1 and Fig.2.4)
14 - Isolated Daisy-Chain Connector (Standard RJ45)
14 1, 2, 3, 4, 7, 8 Not Connected
14 5 Isolated daisy-chain communication port (ISO-)
14 6 Isolated daisy-chain communication port (ISO+)
15 - Isolated Daisy-Chain Connector (4-pin), the same lines as connector 14
15 1 Isolated daisy-chain communication port (ISO+)
15 2 Isolated daisy-chain communication port (ISO-)
15 3 Isolated daisy-chain communication port (ISO+)
15 4 Isolated daisy-chain communication port (ISO-)

Table.2.13: SW1 Descriptions

Part Lever Description (see Fig.2.1)
SW1 - CAN and RS485 Termination Switch: ON puts 120 Ω across the line, only at the two ends of a line
SW1 1 Lever 1: not used
SW1 2 Lever 2: RS485 termination, 120 Ω between RS485 A and B (connector 4 pins 5 and 2)
SW1 3 Lever 3: not used
SW1 4 Lever 4: CAN termination, 120 Ω between CAN H and CAN L (connector 5 pins 4 and 2)