The BLS is compatible up to 2s lipo. The BLX is compatible up to 3s lipo. I bought this charger on amazon and have had no problems so far. You will also need to pick up an adapter for the charger. Look for a male ec3 to femail deans adapter.
https://www.amazon.com/gp/aw/d/B00HQ...?ie=UTF8&psc=1