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| Source: Tata Motors |
We all know that earlier versions of tata cars only had passive balancers which was causing issue with battery balancing over a longer run. Because of this few of the battery packs were also required to be balanced externally in order to bring them back to operational conditions. Since a very long time it was being believed that Tata EV cars are only using passive balancers for balancing their battery packs. But recent studies done by us has revealed results of possibility of presence of Active Balancers in recent cars.
Passive Balancer:
It is a kind of balancer which only balances all the cells of the battery pack
when it is charged all the way up to 100% and having a voltage delta.
Active
Balancer: This balancer has the capability to balance the cells of the battery
pack whenever it finds voltage delta between the cells of the battery pack.
Hence, this can prove to be better option and convenient too for having a
balanced battery pack with minimal issues.
For this we
have been studing battery packs used in various cars and based on that various
data is being published over this blog. Now I will be sharing data for Tata
cars which are having latest battery packs. These data is showing clear indication
of presence of active balancer in the battery pack.
Nexon 45
To test
whether car battery is able to balance at lower SOC for any imbalance in
battery cells, owner of the car was taking readings for battery cell voltages
at lower SOC. When he reached 23% SOC this was the data from his nexon 45 car.
At 20% SOC,
readings were like this
After
reaching at this SOC, he had some work so he shut down his car for almost 3
hours. When he returned back to the car and took back the reading. To great
surprise, reading were like this
This is
indicating that battery pack got balanced on its own even when car was in idle
state with powered down. Then he further ran down his car at 17% with these
readings.
At 13% SOC
Even one
punch ev owner shared the similar experience where he had 140mV delta at 100% but
when came down till 14%, this were the stats.
This is
showing an indirect sign of active balancer present in Tata batteries and
silently working to keep the battery pack balanced enough for making them fault
free.