by using a charger
If it is an automatic charger let it charge until the charger shuts off.
No,but you can charge it from an ihome when not using it.
You can - but it will take longer for the phone to charge.
Other than using a charger to charge the 3DS, the only other option is to replace the 3DS battery with a fully charged one.
As long as it is a 12 volt battery you can if you set the charger on low.
You do not charge a battery using a battery eliminator. The eliminator is not a charger, it is an eliminator that allows you to run the device.
You can charge your Touch by connecting it to any computer's USB port, by using a plug-in USB power supply, or by using some form of USB battery pack. I don't know if any of these fit your definition of "without using a charger".
U cant
Go to the store where you bought the phone and request a new charger or see if you are using the charger wrong.
You cant
It is not recommended to use a 12 volt charger to charge a 14.4 volt battery as the charger may not provide enough voltage to fully charge the battery. Using the correct voltage charger will ensure efficient and safe charging of the battery.