The NiMH charger can be used to charge Lithium cells, however, not in balanced charging.
The Lithium cell will suffer the same problem as that of the NiMH cell after repeatedly charging and discharging: Every cell is not in balanced state, which reduces the life of the battery and deteriorates its function.
In general, many classical chargers can charge Lipo cells. Since the charging current can reach 10A, it can complete charging process of Lithium cells in a short time. While balance charger is inferior in this part since it cannot afford more than 5A charging current due to the high resistance in electric wires
A variety of balance charger for lithium cell can be chosen in the market. They usually possess the same major functions however they show slight difference in particulars. The balance charger shown in the figure is used for reference.
2 to 6 Lithium Cells can be used for balancing and discharging process, however, only one set of battery can be chosen to work.
Demonstration: How to use Charger to charge lithium cell
Firstly, connect two 5000mAH lithium cells to the balancer.
As shown in the figure.
The voltage of the lithium cells will be shown on the display.
We can see a different voltage across the 2 cells.
Adjust the balance voltage at 3.3V, which means that the balancer will carry out balance discharging for voltage greater than 3.3V.
This adjustment is needed to perform once unless there is special request.
Start charging.
Notice: choose the correct type of cells. If NiMH cell is chosen instead, the result will be disastrous.
Press {Balance} on the balancer to start balance discharging.
The lithium cell is undergoing balancing while charging at the same time.
“=” means that balance discharging is in process.
The arrow points to the cell which is acting.
The balanced state is reached although the lithium cells are still charging.
The balancer will be switched off automatically when balancing process is done. This is to avoid ongoing discharging to make incomplete charging process.
Charging is still in progress.
Approximately 30 minutes is needed to charge from 3.9V to 4.2V under a charging current of 1C. It saves a lot of charging time!
During the charging process, the lithium cell balancer keeps an even voltage for the every cell, so that the voltage for every cell is kept at 4.2V when charging is done. The balancer will be closed automatically when it completes balancing. This can avoid unnecessary discharging.
Take the above 2 lithium cells as the example: the fully charged voltage is 8.4V in series. However, if balancing is not commenced during charging, cells will be charged unevenly; 1 cell with 4.1V whiles the other 4.3V. To make things worse, 4.0V and 4.4V, and may even worse! This is because the sum of voltages will always equal to 8.4V in series charging. And the series charger will only compute the total voltage and stops until the number reaches the preset limit, it will not care whether the cells are charged in balance or not.
There are no lithium cells with absolutely same nature, therefore, they should be charged under balancer in order to make them safe and reliable.
You may have a try!
