3. BMS3610 Battery Connection

BMS3610 measures up to 36 cells in series on the board, as two modules of up to 18 cells, and up to 8 slave modules over the isolated daisy chain. This page first shows the BMS3610 in a typical battery system, then how to wire the supply and the button, the cells of both modules, the temperature sensors, the current sensor, the slave modules, the outputs and inputs and the communication ports, and what to set in LiMon™ afterwards. The connector numbers are those of the pinout.

3.1 BMS3610 in a Battery System

In a typical system the BMS3610 measures the cells and the temperatures of the pack and the pack current with a Hall sensor on the negative cable. It switches a separate discharge path to the load, with a precharge branch, and a charge path to the charge socket; three of its high-side outputs drive the coils of the charge, discharge and precharge contactors through mini relays. The sense contact of the charge socket goes to isolated input 1, set to CHG Power Path Interlock, so that the pack cannot discharge while the charge cable is plugged in. The BMS runs from the pack through a fuse, from a tap of at most 80 V on a larger pack, talks to the inverter, the charger and a DIS700 or DIS110 display over CAN, to a PC with LiMon™ over the service port and to a Modbus master over RS485. A pack with more than 36 cells adds slave modules on the daisy chain.

Fig.3.1.1: BMS3610 in a Typical Battery System

Typical BMS3610 system: battery pack, a discharge path with discharge contactor and precharge branch to the load, a charge path with charge contactor to the charge socket, the socket sense contact on isolated input 1 as CHG Power Path Interlock, mini relays on OUT 1 to OUT 3 for the contactors, current sensor on the negative cable, cell taps on connectors 2 and 5, NTC sensors on connectors 1 and 4, supply through a fuse, CAN to the inverter, the charger and a DIS700 or DIS110 display, RS232 through an INT201 to a PC with LiMon, RS485 to a Modbus master and the daisy chain to the slave modules

Tip

The figure uses layout C of User Manual 3.8 Power Path: separate charge and discharge contactors with a charge interlock. One main contactor for both paths is layout A there; the precharge itself is in User Manual 3.9 Precharge.

3.2 Power Supply and User Button

BMS3610 runs from 12 to 80 V on VIN+ of connector 17, or from a 12 V supply on 12Vin of connector 16. Use one of the two, never both at the same time. On a pack of up to 80 V take VIN+ straight from the pack; on a larger pack take it from a tap of the pack that stays at 80 V or below, for example C18+, or use 12Vin. The board starts with a press of the user button, a push-button between VIN+ (connector 17 pin 2) and BUTTON (pin 3); connector 16 pin 4 is the same button input for a button that sits elsewhere.

Fig.3.2.1: BMS3610 Supply and User Button


BMS3610 v1.1 supply from the pack or a pack tap on connector 17 with the user button, and the optional 12 V supply on connector 16

Tip

What the button does after the start, and how the BMS shuts itself down, is in User Manual 3.11 Button and Shutdown.

3.3 Cell Connection

The board measures its cells as two modules. Connector 2 takes the lower cells, up to 18, as Module ID#0; connector 5 takes the cells above them, up to 18, as Module ID#1. Pins 1 and 2 of connector 5 (C19-) are the bottom of Module ID#1, so they take their own wire from the top of the last cell of Module ID#0, the same point of the pack as the top pin of connector 2. Split the cells evenly between the two modules, for example 15 and 15 cells for a 30S pack; a pack of up to 18 cells can use connector 2 only.

Danger

Connectors 4 and 5 are at the potential of the upper module, up to the full pack voltage above B-. Check their wires before you plug them in.

Warning

Take C1- and the tap of the top cell on wires of their own, not from the B- and B+ power cables of the pack. A wire shared with the load current drops voltage and gives wrong cell readings.

Info

Tie the unused inputs of each module to its highest cell, on the cell measurement cable or at the connector; open inputs give wrong cell measurements.

Fig.3.3.1: BMS3610 Cell Connections for 36S, 30S, 25S and 23S Packs


BMS3610 v1.1 cell connections: a 36S pack as 18 cells on connector 2 and 18 cells on connector 5, and 30S, 25S and 23S packs as 15 and 15, 13 and 12, 11 and 12 cells with the unused inputs tied to the highest cell of each module, connector 5 pins 1 and 2 on their own wire from the top of the lower module

Tip

After the wiring, check the cell counts as 3.9 describes.

3.4 Temperature Sensor Connection

BMS3610 has two NTC connectors with the same pins, five sensors each: connector 1 for Module ID#0 and connector 4 for Module ID#1. Each sensor goes between its NTC pin and the GND pin below it. The GND of connector 1 is the bottom of the battery (C1-); the GND of connector 4 is at the potential of C19-, so put its sensors on the cells of Module ID#1. In LiMon™ Live View the sensors are T1 to T5 of their module.

Fig.3.4.1: BMS3610 Temperature Sensor Connection


BMS3610 v1.1 temperature sensor connection: five NTC sensors on connector 1 for Module ID#0 and five on connector 4 for Module ID#1, T1 to T5 per module

Tip

Leave the pins of an unused sensor open: an input without a sensor is ignored. Check in Live View that every connected sensor reads a value.

3.5 Current Sensor Connection

A Hall current sensor with a 5 V supply connects to connector 3: its output to CS-CH1 (pin 1), a second range of a dual-channel sensor to CS-CH2 (pin 2), its supply to CS-5V (pin 3) and CS-GND (pin 6). The figure shows a LEM DHAB S/133, a dual-channel sensor whose high range goes to Ch#1 and its low range to Ch#2. The sensor type, the channels and the coefficients are set in LiMon™; see User Manual 3.6 Current Measurement, which gives the values of this sensor.

Fig.3.5.1: BMS3610 Current Sensor Connection, LEM DHAB S/133


LEM DHAB S/133 on BMS3610 connector 3: pin B high range to CS-CH1, pin D low range to CS-CH2, pin A 5 V supply to CS-5V, pin C ground to CS-GND

3.6 Slave Modules via Isolated Daisy Chain Communication Port

BMS3610 drives BMS1802 or BMS1202 slave modules over one isolated daisy-chain port, RJ45 connector 7 or 4-pin connector 6. The start of the line is terminated on the BMS3610 board. The two modules of the board are Module ID#0 and ID#1, so the first slave is Module ID#2.

Fig.3.6.1: BMS3610 Isolated Daisy Chain to the Slave Modules


BMS3610 v1.1 isolated daisy chain from the master to three slave modules

Tip

Use CAT5e or CAT6 cable, up to 50 m. How each slave is wired in and out, how it takes its module ID and how the line end is closed is on its own page: BMS1802 Battery Connection or BMS1202 Battery Connection.

3.7 Outputs and Inputs

The four high-side switches on connector 15 drive mini relays and other small loads, not contactor coils: a contactor is switched by the contact of a mini relay, from its own supply. The outputs switch the 12 V of the board, or an external supply on Vext (pin 10) when it is above 12 V, for example 24 V for mini relays with a 24 V coil; the loads and the minus of the Vext supply return to GND on pins 1 to 5. The relay on connector 8 is a free contact (COM, N.O., N.C.). Connector 9 carries the isolated inputs and the isolated TTL outputs with their own ISO GND on pins 1 to 5: an input is active while it is at ISO GND, through a closed contact or a 0 V logic signal (5 V or open is inactive), and a TTL output gives a signal, not the current for a load. What each output and input does is set in LiMon™; see User Manual 3.10 Inputs and Outputs, whose Table.3.10.4 lists the pin of every LiMon™ number.

Fig.3.7.1: BMS3610 Output and Input Examples


Six examples: a contactor through a mini relay on OUT 1 with the board 12 V, the same with Vext from a 24 V supply, a lamp on the relay, a switch on isolated input 1, the isolated TTL output 5 to a controller and a 5 V logic signal on isolated input 2

Warning

Do not connect a contactor coil straight to a high-side output; use a mini relay. This manual gives no current rating for the outputs, so check any other load with LiBat™ first.

3.8 Communication Ports and Termination Switch

RS232 (the service port for LiMon™) and RS485 are on connector 11, CAN on connector 10, all isolated from the battery. CAN and RS485 are lines with a 120 Ω termination at each of their two ends. The termination switch SW1 has two levers for each line: levers 1 and 2 terminate RS485, levers 3 and 4 terminate CAN, and the two levers of a line switch the same resistor. Set the levers of a line ON only when the BMS3610 sits at an end of that line. The settings of the ports are in User Manual 4.1 Communication Ports.

Fig.3.8.1: BMS3610 Termination Switch SW1

SW1 with four levers: levers 1 and 2 RS485 and levers 3 and 4 CAN termination; three examples with the BMS at both line ends, at the end of the CAN line only and in the middle of both lines

3.9 Settings in LiMon™ and First Check

After the wiring, set the cells and the slave modules in LiMon™ and restart the BMS so that it finds them:

  • Module ID#0: the cell count measured on connector 2 (5 to 18).
  • Module ID#1: the cell count measured on connector 5, or --- when connector 5 is not used.
  • Slave Module Type Selection: BMS1802 or BMS1202, or --- without slave modules. All slaves of one master are the same type.
  • Module ID#n: the cell count of every slave module, from ID#2 up, up to 8 modules (User Manual 3.1 Battery Topology).
  • Save, restart the BMS and check in Live View that every module is there with the cell count you set. The full procedure is in 2.1 Commissioning Checklist.

Table.3.9.1: Wiring Faults and What the BMS Reports

Wiring fault Event What to check
A cell tap missing or loose, an unused input not tied to the highest cell, or a cell count in LiMon™ that does not match (26) Cell Connection Error Connected Cells of the module, then its cell connector and the cell count in LiMon™
Connector 5 or its C19- wire not connected while Module ID#1 has a cell count (29) Slave Module Communication Error Connector 5, the wire from the top of Module ID#0 to its pins 1 and 2, and the Module ID#1 cell count
A daisy chain cable or connector broken, or a slave module below 11 V (29) Slave Module Communication Error Which module is missing in Live View, then its cables and its cell voltages
A temperature sensor not connected or its wire broken none; the input is ignored That the sensor reads a value in Live View

After a fault is repaired, restart the BMS. All events and their causes are in 6.1 Events and What to Do.