If its a Orion or a Kokam lipo, you may be able to do without a balancer, for anything else, find an adapter so you can balance your 2S.

There are 4 balance connections in use today - JST-XH (also called Align style), PolyQuest/Hyperion, Kokam and Thunderpower. Find out what you were using (charger) and what the new lipo uses and then you'll know what adapter you need to make it work.