Every RC modeller has some sort of support equipment. There are plenty of occasions flying electrics when all you need is your model and transmitter but for any kind of extended flying session you need more on hand, especially a charger.

My field box is about pushing 14 years old now and on its third coat of paint. It started life providing support for my .40 Aeroflyte Hustler. Now the tin of fuel on the end has gone and it’s full of gear for my ‘leccy planes. I bought my Swallow charger a while ago from my local hobby shop Ace RC Models and it’s been serving me very well. I thought it was time I sorted out something permanent yet versatile.

I had been running it from an AC adapter I’d built from a computer power supply for some time but this has always meant charging at home. I had a 12V 7Ah battery laying about so decided to use this for a field power source. The problem was how to use this at the field and a power supply at home - easily. This is what I came up with.

An aluminium panel serving as a lid to replace the original one (disgarded years ago). This lid now serves as a mount for the charger and the electric componentry. I’ve added two panel mount banana sockets, two 5A circuit breakers and a pair of two pole double throw toggle switches. The switches have ‘missile’ covers to prevent accidental switching, these are completely necessary and not at all for wank factor.

  • With both switches ‘down’ the panel is configured to charge model batteries from an external power source (eg modified computer power supply, supply via banana sockets on panel)
  • With the red switch ‘down’ and the black switch ‘up’ model batteries can be charged using the internal 12V 7Ah battery as the power source.
  • With the red switch ‘up’ and the black switch ‘down’ the internal battery is charged using the Swallow, power from an external power source.
  • With both switches ‘up’ – fireworks! charges the internal battery using the same battery for the power source.

Here’s a few piccies. You can see the nice long charge lead I made up from 14 gauge silicone insulated wire. That makes charging batteries inside a fire resistant ‘LiPo sack’ much easier.