Motorcycle Charger is the exchange of AC into DC, the motorcycle output 12V is the exchange of electricity into 5V regulator charger.
How to use the motorcycle charger?
Motorcycle charger Charging need to limit the current limit, usually simple charger is generally limited, as long as the voltage design is below the charge battery limit, the current is required by the battery automatically charged, the beginning of the high current, when the battery voltage close to the Charger design voltage when the current will be very small to stop, generally do not worry about filling the battery.
Electrical damage is usually due to excessive voltage caused by increased current damage.
In fact you have to worry about the voltage rather than the current.
The voltage of the car only 12V and 24V, you look at your car charger input voltage is not 12V, if it is directly connected to nothing. If it is connected to the 24V can not work properly.