Do I need to use up the Ni-MH rechargeable AA batteries before recharging them? Should the charging time be shortened by half between half-charged and fully-used charging?

The nickel-metal hydride battery used in the camera needs to withstand a relatively large current to support the normal operation of the camera, so it is certainly powerful when used in toy cars. This kind of battery can be charged with a termination voltage of 1.2 volts. After it is fully charged, it is measured at 1.5 volts under no load.

Theoretically speaking, discharging and then charging can make the battery more durable. But if you don't have a suitable discharge method, it is very likely that the battery will be over-discharged, which will affect the battery life.

That is to say, the termination voltage needs to be detected during the discharge process. It charges immediately when it reaches 1.2 volts.