This is a standard generic charger for Casio NP-20 batteries.
It has fully-automatic charging circuitry with automatic shutoff when
the battery is fully charged.
Each charger comes with an auto-switching 110-240V AC adapter and
a car adapter. Exactly as pictured. If you don't plan to use it in the car,
you can leave the car adapter at home. If however, you need to use it in
the car - it is just as convenient to have the car adapter plugged into the
cigarette lighter jack and charge the battery while you drive.
A nice to have item when you are on the go.
Charger equipped with dual-color LED. When battery is placed on the
charger, the LED turns red and remains red during the charging process.
When the charge is finished - the LED turns green.
Power supply input voltage: 110V-240V
Power supply output voltage: 12V - 24V
Charging voltage limit: 4.2V max
Charging current limit: 650mA max
For batteries rated: 3.6V - 3.7V average
Q: Why is the battery 3.7V and the charger outputs 4.2V?
A: The charger is limited at 4.2V, but does not go to 4.2V immediately
when the battery is just plugged in. It first charges the battery at a constant
current until the voltage reaches 4.2V. Then, it stays at 4.2V for a few minutes.
Then it shuts off and the LED turns green. This is according to Li-Ion charging
specifications. It is different from Ni-MH or Ni-Cd battery charging.
Read our FAQ for battery charging tips.
Q: Why would the LED turn red and immediately turn green with my battery?
A: Your battery is "dead". It has lost over 90% of its capacity. This usually
happens when you overdischarge the battery too much. Read out FAQ for battery usage tips. You need to get a new battery.
Q: The LED never turns red but my battery works. Is the charger bad?
A: There is a chance the battery terminals do not touch the charger contacts
all the way or became dirty. Please, check that. If necessary clean the battery
terminals or slightly bend the charger contacts to have a better connection.
If this is not the case - then yes, the charger is bad. Generally, these chargers
have a very low rate of returns. Less than one in 500.