Blog - Battery Monitoring

What is appropriate product for the balancing of battery cells?

----------------------------------------------------------

First, it is important to realize what the real charge current in the circuit for the end of charging.
So about voltage from 3.55V - 3,6V for Cell, here is recommended to start balancing.

We offer a variety of products, ranging from a simple module CBM1, 
to professional BMS system with data bus and control unit.

- CBM1 modules are passive modules for the balancing.
These modules do not solve the issue of monitoring the status of the battery.
These modules are therefore necessary to supplement with the monitoring unit CellLoger
http://www.ev-power.eu/_d1747.html
Please note, that CBU1 balancing maximum current of 1.7 A.

If the charging current of 20A for example, then the balancing 1.7 A weak,
because it will flow into the battery further difference of these currents. Thus, in this case the remaining charging current of about 18A.
So it may be required to compose multiple modules CBM1 parallel to each other, to the balancing flow increased.
See real circuit examples here:
http://gwl-power.tumblr.com/tagged/CBM
It is also necessary to reduce the charge at the end of the current to the individual cells managed to equalize voltage.
All of our chargers are designed for LiFePO4 technology and the reduction of the current at the end of charging contain.
This is suitable for battery packs, composed of small battery cells. Capacity of about 8Ah to 20Ah.


- It is also possible to use a smarter SBM units. These units combine small balancers,
(again, very low current the balancing about 0.5 A) and also the electronic disconnector of flowing current
to the load, and also from the charger. Disconnector responds to the limit voltage states.

These SBM modules are always made ​​for a specific number of cells in series.
Thus, 4, 8, 12, 16 cells. And for disconnecting traction currents max.10A or bigger models for a maximum of 60A.
If it is necessary to disconnect the current greater than 60A, then it is necessary to use an external contactor and
to involve the control circuit coil through SBM module instead of the traction circuit.
See scheme and information here:
http://www.ev-power.eu/docs/SBM-Installation-DC-Contactor.pdf
Caution, SBM modules need to mount the exact number of cells on that particular module is made for.
If you involve fewer cells, the module does not work.
This is already suitable for mids-mall battery packs. Capacity of about 40Ah to 90Ah.


- As a complete solution for protecting battery packs, we offer professional modular system BMS123 Auto, BMS123 Smart and BMS2405.
This is suitable for all installations that are expected ability to change settings and measure capacity.

This system requires greater proficiency for installation, but also provides several
possibilities of control, data logging, smooth control current of the connected charger and balancing cells about current 3A.