This is the one I use - it has an extra lead so you can hook up charger. When the switch is off, hooking up charger to the spare lead lets you charge the rx batt without doing anything extra - like unplugging it or taking it out of the box. There are others made without the spare lead.


http://www3.towerhobbies.com/cgi-bin...&I=LXL303&P=ML


You use yor dvm ohmmeter to figure out which way you want to install it - its pretty straightforward.