Don't charge with a 9V, you'll be wasting way too much power from an expensive battery.

You could charge with 3 AAA's for like a minute by direct connection if the batteries are wired in series. Charge with 2AAA for 1.5 - 2 minutes if they are wired in parallel.

You could also charge it with a zzmt remote since zzmts are dual celled, again if it is wired in series.