The Common Sense One Piece T-Style to Traxxas Adapter Plug will allow you to connect any T-Style equipped battery to an ESC or charger with Traxxas High Current, or Traxxas iD type male connectors. Package includes two adapter plugs.
NOTE: This adapter is not recommended for charging applications and should be used as an ESC/Battery adapter only.
Get hold of multimeter to measure the balance port and +- port on the battery and see reasonable voltage 3.8V and 7.6V. I then tend to believe EZ peak charger might have some issue so searched on YouTube to see there are many people having success charging Gens Ace battery with EZ peak charger. I almost pulled a trigger on purchasing a Protek charger and Protek shorty LIPO but finally I decided to give it a try by prying the metal contact upward a little bit inside the adaptor plastic housing. That is the magic and now the charger can recognize the battery and starts charging once plugged in.
However, now the adatpor won't plug into the male traxxas connector on the ESC, just because the slightly tilted metal contact inside the adaptor is in the way. I compared the traxxas female connector and this adaptor, both of which are supposed to work the same. I found the traxxas female connector has metal contact on both sides inside the plastic housing, which can "pinch" the male connector to have solid conductivity. This adaptor does not, which might explain why the charger won't recognize it maybe because of the bad metal2metal contact in the first place.
Anyway I do not recommend this product.