smallBMS with pre-alarm

A simple and cost-effective alternative to the VE.Bus BMS

The smallBMS can replace the VE.Bus BMS in several applications. However, it is not suitable for use with VE.Bus MultiPlus and Quattro inverters/chargers: This is because there is no VE.Bus interface. The smallBMS is designed for use with Victron Smart LiFePo4 batteries with M8 round connectors.

The smallBMS has two outputs, similar to the VE.Bus BMS.

A simple and cost-effective alternative to the VE.Bus BMS
The miniBMS can replace the VE.Bus BMS in several applications. However, it is not suitable for use with VE.Bus
MultiPlus and Quattro inverters/chargers: This is because there is no VE.Bus interface.
The miniBMS is designed for use with Victron Smart LiFePo4 batteries with M8 circular connectors.
The miniBMS has three outputs, similar to the VE.Bus BMS.

"Load Disconnect" output
The load output is normally high and becomes free floating when the cell is energized (standard 2.8 V/cell,
adjustable on the battery between 2.6 V and 2.8 V per cell). Maximum current: 1 A. The load output is not
short-circuit protected.
The "Load" output can be used to control the following functions:
- A high current relay or contactor
- The remote on/off input of BatteryProtect, inverter or DC-DC converter or other loads.
(A non-inverting or inverting cable for on/off switching may be necessary. Please refer to the detailed manual on our website
).

Pre-alarm output
The pre-alarm output is normally free floating and will go high if there is a risk of cell undervoltage (standard 3.1
V/cell, adjustable on the battery between 2.85 V and 3.15 V per cell). Maximum current: 1 A (not short-circuit proof).
The minimum delay between pre-alarm and load disconnect is 30 seconds.

"Charge disconnect"output
The "Charger" output is normally HIGH and becomes "free floating" if a cell overvoltage or overtemperature is imminent. Maximum current: 10 mA.
The "Charger" output is not suitable for operating an inductive load such as a relay coil.
The "Charger" output can be used to control the following devices:
- Remote on/off switch of a charger
- Cyrix-Li charging relay.
- Cyrix-Li-ct battery coupler.

"System on/off" input
The "System on/off" input controls both outputs. If it is off, both outputs are switched to "free floating". The loads
and chargers are therefore switched off.
The "System on/off" input has two connections: Remote L and Remote H.
A remote on/off switch or a relay contact can be connected between L and H.
Alternatively, connection H can be connected to a battery positive terminal or L to a battery negative terminal.

Protects 12V, 24V and 48V systems
Operating range voltage 8 to 70V DC.

LED indicators
- Load ON (blue): Load output high (cell voltage > 2.8 V, adjustable at the battery).
- Temp or OVP (red): Charger output "free floating" (due to cell overtemperature (>50°C), cell
undertemperature (