battery charger question

[elty]

I have a Panasonic charger BQ-395 for NiMH battery... it seems it don't know when to stop charging. will ti cause any harm if i overcharge/undercharge the battery? How long does a typical charger takes to fully charge the battery? mine doesnt have a box to tell me.

It said the output of it is 2.2A, does it means it will take about 4 hours to fully charge 4 2100mA battery?

[Cons]

stopping the charging activity depends on the design of the charger.if it is designed to detect and stop charging then it will,one way is using a zener diode and/or diodes to stop current flow when anough voltage is accumulated. and yes AFAIK overcharging will damage ur battery,a leak i think.i just got my wireless kb/mouse(a4tech) and i dont want to overchrge it. 2100mA is the same as 2.1ampere. im not sure about the charging time though. i saw a circuit diagram of a battery chrger b4 but cant remember the exact design.u could easily make one if u can solder.hope this helps