MAKE YOUR OWN DISCHARGER CHEAP!

Every RCer should have an expanded scale voltmeter. Use it before every flight in the beginning days of each flying season and any time you have a doubt about the battery.

Cut a servo extension lead in half and solder bannana plugs onto the ends so you have both ends coming off bannana plugs. Solder a female end onto a common 12v car light bulb and heat shrink it (tape won't work cuz they heat up).
Plug the bannana plugs into the expanded scale volt meter, battery on on end and light bulb on the other. now you can discharge any flight or radio battery to the correct discharge level.
Don't go in the red. Recharge with whatever you have for a charger. Wallwarts work just fine for this. 16 hours charge time. Repeat 2 to 5 times and you should be good to go.
Cycle the batteries every spring and the new packs as mentioned and any time they have been stored. Charge all the batteries a couple times over the winter too.