1. http://www.technobots.co.uk/index.html?lang=en-uk&target=d338.htmlhttp://www.technobots.co.uk/index.ht...rget=d338.html the dual output 13.8V 20A will do the job for you
2. You still cant use that receiver even with external failsafes - as I understand it the AR will continue to transmit a signal that your failsafes will permit. Thats why the BR receiver is a must.
3. Youre OK just giving them one or two cycles when you get them if theyre lacking a bit in voltage but dont do anything more needlessly, you wont increase the performance at all. Try to slow charge the packs when you are though and only fast charge when you have to at events.