Appendix; Only One Current Sensor Or Cable; Multiple Battery Cells Or Packs Parallel; Switching Combined Charger/Inverter - 123electric Smart BMS gen 3 Manual

Appendix

a. Only one current sensor or cable
It is possible to only use 1 current sensor, the
BMS will also work perfectly fine. Using one
sensor will use less power on the Begin Board.
The drawback is that you cannot measure
incoming and outgoing currents
independently, but only see the current going
in or out the battery pack.
Connect the current sensor to "Sensor 1" on
the Begin Board and make sure to see a
positive current in the app next to the battery
icon when charging and a negative current
when discharging.
b. Multiple battery cells or packs
parallel
There is a difference between placing multiple
cells parallel or packs parallel.

Multiple cells parallel
You can safely place multiple cells parallel and
only need 1 BMS cell module per parallel
group. For instance: a 12V LiFePO4 pack
consists of 4 cell groups in series. In case you
have 8 cells, the pack is configured as 2P4S
(groups of 2 cells parallel, then these parallel
groups in series). In this case you only need 1
BMS for 4S (4 cell groups).
123electric
The Netherlands
E-mail: info@123electric.eu
www.123electric.eu

Multiple battery packs parallel
When you have to connect multiple packs
parallel, you need 1 complete BMS per pack.
You can connect the signal relays on each End
Board in series. For instance: with 3 packs
parallel, you can run the charging signal
through from the first End Board Charge relay
to the second Charge relay and through the
third Charge relay. This signal can switch an
enable/disable or power relay. The same goes
for the Load relays in series.
c. Switching combined
charger/inverter
It is possible to use a combined
charger/inverter. Just use 1 current sensor
and connect this sensor to sensor 1. Make
sure to run the current cable the right way
through the current sensor. When charging,
you should see a positive current in the app
next to the battery icon. When discharging,
you should see a negative current.

Combined charger/inverter with two
enable/disable signals, one for charger
and one for inverter
You can keep the BMS in "normal mode"
and use the charge relay for the
enable/disable signal of the charger and
the load relay for the enable/disable
signal of the inverter.
24