If you’ve bought an electric truck from Redcat Racing since 2011, you probably have Hexfly brand batteries with 4mm banana plugs. These connectors are inexpensive, offer polarity protection, and can handle the current demands of high performance modern electric trucks. However, many battery chargers sold today do not come equipped with compatible banana plug adapters. Not surprisingly, customers periodically ask how to charge Hexfly batteries with banana plugs.
With LiPo batteries, there is a very simple solution. All brands of these batteries, including Hexfly, come with a balance charging connector and these will charge fine through any standard balance charger. NiCd and NiMh rechargeable batteries must be charged through the banana plug, of course. Many chargers, including the popular NiCd and NiMh smart chargers from Tenergy, come with alligator clips that can be used for this purpose. The video below shows how it is possible to safely charge batteries with 4.0mm banana plugs using these clips.
Another option is to use an adapter between the banana plug on the battery and a standard plug on a charger. Nearly all chargers come with a Tamiya plug and you can connect a Hexfly battery to one of these using a female Tamiya to banana adapter (Redcat Racing part ST-TAMFTO4B, RCTO1419).