I recently purchased a set of NI-MH batteries online for their long lasting power, and so far they serve me well.

In one order, I have received a free battery charger which charges the batteries ok, but I think it takes a while.

The specs of the batteries on-hand are:

Battery 1: 6800mAh 7.2V
Battery 2: 4000mAh 7.2V

And the writing on the charger is as follows:

POWER
NI-CD NI-MH
IN:AC 110-240V
OUT:DC 1.2-12V
100-220mA

It includes a red light that is on when the charger is plugged in and the battery is connected to it.

I'm thinking for a charging boost, I could buy one rated for 9.6V at 400mA instead of using mine which goes up to 220mA

The item I'm thinking is listed here: https://www.ebay.ca/itm/9-6V-400mA-US-plug-charger...

Would this be a wise choice? or could I even pick a charger that's tated for 2000mA without a problem?

The charger I found with this power is listed here: https://www.rchobbiesoutlet.com/7-2-volt-rc-charge...

What are my limits?