You can charge with two 4.8V chargers, but you need to install a voltage detector. Once the battery voltage reaches 4.2V, you need to unplug the charger.
The safest way to charge is to charge. Of course, install a voltage detector. 7.4V protection circuit, so that battery failure will not occur due to excessive voltage, and you don't have to worry about the battery discharging below 2.5 V during use. it also has overcurrent protection and short circuit protection functions