Faktor BMS123 Smart User manual

User Manual
BMS123 Smart

Introduction
After the introduction of affordable LiFePO4 batteries, off-grid solutions became available for wide
public. It is vital that such batteries are charged very carefully. In other words, they can easily be over-
charged, or over-discharged. Cell-temperature and current are also very important, in order to
guarantee a long life.
The GWL Battery Management System ( or : BMS ) is primarily intended for prismatic LiFePO4-
LiFeYPO4-cells, but can also be adapted by the end-user for other cells like Li-Ion and LiPo, provided the
cell-voltage is in the range of 2V to 5V.
Keep the batteries in perfect condition
The drawing below shows that your expensive batteries are in good hands with 123 electric.
The system sets the coulomb counter to 100% when either all cells get to V-bypass or one cell reaches V-
max. (You can change these settings with the PC software by yourself.)
Calibrating the coulomb counter to 100% is important, as otherwise small errors will appear, because of
changes in the charging efficiency, aging of the batteries etc. etc.
The width of the green (safe) area, can also be selected by yourselves. If you use 90 Ah cells, for instance,
and you only want to use 60% of the capacity, you can enter 60% of 90 Ah = 54 Ah in the field for Cell-
capacity.

Conclusion : the upper limit is safe-guarded by entering V-max / V-bypass, and the lower limit by V-min.
Package contains (12 Volt, 4 cells)
- IN Cell Board
- OUT Cell Board
- 2 Cell Boards
- 2 Current sensors
- Piece of 0,75 mm² wire for the interconnections
- Connector unlock tool

Specification
Placing the cell modules
Please be aware that your battery-pack contains a large amount of energy, which can be potentially
dangerous. Use isolated spanners, to prevent any short circuits. High inrush currents, causing arc-ing (
sparks ) and ultra-high electromagnetic levels, can easily damage electronic circuits.
We therefore strongly recommend to always FIRST connect the so called "large current connections"
in a new setup, and THEN separately connect the BMS-boards.
A good way of doing this is indicated on photo number one. After thorough cleaning of the cell-poles,
the copper strips are bolted-on. Don't forget to also attach wires to the first and last cell in the same
way, and connect these to the solar panels, MPPT, charger and the load.
Item
Specifications
Idle Current of the BMS-IN / OUT Modules
inclusive current sensors and standby Bluetooth
< 2 mA
OUT Module current when Bluetooth
connection is active
<25mA
Idle Current BMS-modules
< 100 uA
Balancing Current
1 Amp.
Number of Cells
2 - 255
Current-sensors
100 Amp.
Resolution
10 Bit A/D converter
App compatibility
iOS, Android

Mounting the IN Module
Start to mount the IN-Board on the first cell. It is important this is the cell on the minus (-) side of the battery
pack. Solder a wire on the solder pad of the IN-Board. (Photo 2) Connect this wire to the minus (-) side of the cell.
After the IN-Board is connected the LED will start blinking every second, this shows the IN-Board is trying to send
out data messages to the following cell board.
Install a current sensor in the incoming power line (solar panels, PMMT, charger) and connect this current sensor
to the IN-Board connector”J1” marked “I-1”. Install the other current sensor in the power line of the consumers
(inverter) and connect this sensor to the IN-Board connector ”J2” marked “I-2”. Make sure the arrow on the
current sensor is pointing in the right direction. The direction where the current is flowing (see picture on the
following page).
Note: when only using 1 current sensor, connect this sensor to J1.

Mounting the „Between“ cell Modules
After the IN-Board was installed, please proceed by the cell boards. Now, prepare the BMS-boards as shown
on photo number two. Use thick solid-copper wire for this, for optimum accuracy. (the bypass-current has
to flow through these wires)
Take your time: the result has to look good!
The BMS module always has to be mounted on the 'plus' pole of the cell. This '+' is also indicated on the cell
modules. Connect all the modules as shown in photo number three.
Mounting the OUT module
On the last cell (+ side of the battery pack) the OUT-Board has to be installed. This works the same way
as the other cell boards. It’s normal you will hear some clicking relays when you power up the OUT
board.
Cell boards interconnections
After all cell boards are installed the interconnection can be made. Start the interconnection of the IN-Board
to the following cell board. Make a connection from the single connector marked “OUT” on the IN-Board to
the double connector position 1 Marked “IN” on the following cell board. Please be careful while you’re
doing this in order to prevent a short circuit. The single wire is now under power. Do not touch any other
part of circuit by this wire except the correct connector. It could damage the board. After you have made
the interconnection between the IN-Board and the first cell board you will notice the green LED on the next
cell board will flash as well every second. This confirms the cell board was correct installed and the
interconnection between the cell boards are made correct. Now go on with the other cell boards. Make
connections from the double connector position 1 market “OUT” to the next cell board connector position 1
market “IN” If the flashing LED’s stop somewhere in the middle of the cell chain there is an error, in this case
check the wiring.
A four cells 12 volt system needs three connections:
IN-Board J4 “OUT”  Cell-Board “IN” position 1
Cell-Board “OUT” position 1  Cell-Board “IN” position 1
Cell-Board “OUT” position 1  OUT-Board J1 “IN”

The picture below shows a basic setup of a 12
Volt
battery pack

The picture below shows a setup with separated battery banks.
When the battery pack has separated battery banks the interconnection has to be changed to prevent
interference from other components in the system. The data connection has to be galvanic isolated. This can be
done by the following procedure:

1- Cut of the PCB track between the two gold dots. ( red circled in the picture above )
Use a twisted pair cable and use both terminals.
IN-Board 'option switch' functions
Settings
The option switches can be changed when the system is active.
The table below shows you the functions of the option switches.
Important: Don't use switch number 8, this will overwrite hidden factory settings
Switch:
1
2
3
4
5
6
7
Function:
Fast
message
V-
Bypass
Bigger
blind
spot
Set zero
Mode
V-Bypass
ON
Messages every 0,5 Sec.
OFF
Messages every 1,0 Sec.
ON
Blind spot around zero AMP enable
OFF
Blind spot around zero AMP disable
OFF
Auto zero inactive
ON
Auto zero active
OFF
Normal mode (recommended)
ON
Critical mode
OFF
OFF
OFF
V-Bypass 3,4 Volt
OFF
OFF
ON
V-Bypass 3,5 Volt
OFF
ON
OFF
V-Bypass 3,6 Volt
OFF
ON
ON
V-Bypass 3,7 Volt
ON
OFF
OFF
V-Bypass 4,0 Volt
ON
OFF
ON
V-Bypass 4,1 Volt
ON
ON
OFF
V-Bypass 4,2 Volt
ON
ON
ON
V-Bypass 4,3 Volt
Option switch nr 1: The frequency of the cell board messages can be changed by these option switch. For fastest
information set the switch to ON, for saving energy set the switch to OFF.
Option switch nr 3: To prevent the current sensor is too sensitive around 0 Amps and this will cause
miscalculations in the SOC calculation, enable option switch 3. Now the current sensor has a little blind spot
around zero. ( this function is available in version 1,1 or newer )
Option switch nr 4: When the current sensors need to be calibrated follow the next procedure: Make sure there
is running absolutely no current through the current sensors during the zero calibration procedure. On the IN

module you will find the option switches. Set option switch number 4 to the ON position. Now the “Auto zero”
procedure will be active. The currents on the App screen will show 0 Amps in a couple of seconds. Set the option
switch number 4 back to the OFF position again.
Option switch nr 5 (v1.5+): OFF (recommended): the BMS works in normal mode. The SOC is reset to 100% when
all cell voltages are at or above Vbypass. The relays are controlled by the BMS charge/discharge algoritm. Please
see section “Algoritm” for more info.
ON: the BMS does not act on SOC anymore and only switches the relays off in critical conditions like
communication error, too low voltage, too high voltage, too low temperature and too high temperature. The SOC
is reset to 100% if the total pack voltage is at or above Vbypass x Number of cells.
Option switch 2, 6 and 7: Set option switch 2, 6 and 7 in the right positions for the Bypass voltage you like.
See table for details.
Hidden factory settings
The settings below are normally pre-programmed during the production.
For programing other current sensors or change the number of cells follow the next
procedure:
Set all switches below in the right positions for current sensor and number of cells and toggle
switch 8 ON and OFF again.
The hidden settings are now stored in the BMS. Set the switches back in the original positions.
Please be aware it could be necessary to follow the current sensor calibration procedure
again.