I bought a 8.4V 3800mAh Ni-MH battery from eBay. Unfortunately, its charger is not working. I searched about charging Ni-MH batteries on the web. Can I charge this battery with TP-Link power supply which has an output of 9V and 0.6A? I think 0.6A might be too much for this battery but I am not sure. What would be the ideal voltage and current to charger this battery?
This is what you need to charge your battery from 12 V supply:
This will charge the battery pack with about 380 mA. Note that Resistor R1 needs to be at least a 2 Watt resistor (3W, 5W and 10 W is also OK) as it must be able to dissipate some heat.
This is what some resistors look like:
The 3 on the left are OK
The others are too small and not OK, they would burn out.
From left to right these look to me like 5W, 3W, 3W, 1W, 0.5 W, 0.25 W and 0.125 W resistors.