A. Lets take an example of a 48.1V SUMATOTEK Lithium Battery. It has 13 Strings or 13 Rows connected in series. The BMS connector in the picture has 14 wires. You can access this connector by opening the Battery Box Cabinet Cover and after disconnecting it from the BMS. Remember to follow the Safety Instructions given at the end of this FAQ.
C0 : This is also the negative terminal terminal of the Battery Pack. It is also connected internally to the BMS at B- Terminal.
C14 : This is also the positive terminal of the Battery Pack. It goes straight to the output terminals & is also accessible via the Industrial & Charging Connectors. Note : The Main Red(+Ve wire : 4Sq mm ) is directly connected to the connectors. It is not connected to the BMS.
C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13 : These pins are connected to individual rows in the pack.
Our task is to measure the voltage between these pins. If you are using SUMATOTEK Service Battery Health Calculator to analyse your battery health report then you need to measure B0, B1, B2, B3, B4, B5, B6 ,…..B20.
B1 : Voltage Between C0 & C1. If you are using a multimeter (Set the Multimeter to 20V DC Setting) then the Negative Lead(Black Lead) will be placed on C0 & Positive Lead(Red Wire) will be placed on C1. Note down this Voltage, it should be within a range of 0-5V.
B2: Voltage Between C1 & C2. If you are using a multimeter (Set the Multimeter to 20V DC Setting) then the Negative Lead(Black Lead) will be placed on C1 & Positive Lead(Red Wire) will be placed on C2. Note down this Voltage, it should be within a range of 0-5V.
B3: Voltage Between C2 & C3. If you are using a multimeter (Set the Multimeter to 20V DC Setting) then the Negative Lead(Black Lead) will be placed on C2 & Positive Lead(Red Wire) will be placed on C3. Note down this Voltage, it should be within a range of 0-5V.
B4: Voltage Between C3 & C4. If you are using a multimeter (Set the Multimeter to 20V DC Setting) then the Negative Lead(Black Lead) will be placed on C3 & Positive Lead(Red Wire) will be placed on C4. Note down this Voltage, it should be within a range of 0-5V.
B5: Voltage Between C4 & C5. If you are using a multimeter (Set the Multimeter to 20V DC Setting) then the Negative Lead(Black Lead) will be placed on C4 & Positive Lead(Red Wire) will be placed on C5. Note down this Voltage, it should be within a range of 0-5V.
Keep repeating it until you reach ……………………….
B13: Voltage Between C12 & C13. If you are using a multimeter (Set the Multimeter to 20V DC Setting) then the Negative Lead(Black Lead) will be placed on C12 & Positive Lead(Red Wire) will be placed on C13. Note down this Voltage, it should be within a range of 0-5V.
SAFETY INSTRUCTIONS : Do not short the Connector Pins while measuring with the multimeter leads. If the leads touch each other while they are placed on the BMS Connector pins, it could short that particular string/row. Also do not press the Multimeter lead too hard while measuring the voltages, press gently or it might damage the connector. Do not bend or twist the connector in any way while taking it out from the BMS. Pull the connector out slowly in the direction of the connector.