I'm not an electronics guru the main reason is;the stock charger most likely does not fully charge the battery and you can't monitor the charge rates or discharge with the stock charger.This will allow you to be able to fully charge the battery and see what available voltage you actually have and if you have a charger that cycles you can also cycle the battery.You will also be able to see how many mah you are using based on how many you put back in'again if the charger has this feature.With these batteries being so small you will have to have a charger that will adjust down to a low mah setting I'm thinking .1amp
This would be an economical price and probably pretty good.But you have to supply power for it from a power supply or a larger battery.There are plans on the net that show how to use a power supply from a computer to power battery chargers.
http://www.xheli.com/tht6bach16ce.html