Thought some may be interested in a simple way to put together a charger for the shop or field. This took about an hour and not much money. You can be as creative as you want but maybe this could be a start for you. This setup lets you switch from power supply plugged into an AC outlet to off to 12 volt DC hobby battery. It gives you a place to store your node adapters and power cord when at the field. I also added a voltwatch to the 12v battery. The only thing I have to add is a fuse and a charing port for the 12v battery. I velcro'ed the charger on so it could be removed if needed.

Requires:

120vac/12vdc 5 amp power supply. (Ebay for <$15 shipped)
Radio shack switch $4
Radio Shack jacks $2
Battery $20
Charger of your choice
The rest is optional. It is an enjoyable small project. Enjoy!

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Nice set up. Creative, you must build model airplanes.

Nice job. I'm always looking at how people have their stuff setup at the field.
Gives me an idea or two. Thinking about a slightly bigger box, that I could put everything inside of, and then, I could close the lid and make it all weather proof/fuel resistant....hmmm

Thanks.

Another nice feature is that you just put the switch in the power supply position to power the charger and charge the 12 volt battery in the box with the cellpro. It shuts off when it is charged, unlike the wall wart chargers. That leaves no wondering if your 12 volt hobby battery is fully charged.

Weatherproofing it sounds like a great upgrade.