I just finished up building my 2s/3s/4s LIPO battery charging ammo can... I already have a 1s setup that's been working for a year or so and it's worked out well and given me a certain amount of peace of mind. Now that I'm doing 2S and 3S, with 4S on the horizon, I bought a new charger and set it up like this... I pulled almost all of the rubber seal from the lid so that it doesn't become a bomb if something goes wrong. I left one piece on so it still closes tight as it should. The cables are always plugged into the charger. There are female banana connectors inside and the balance boards are double stuck to the sides of the box...