Don't know if chargers are properly considered an accessory as per this thread, but I see other questions about chargers so here goes. I have a universal usb charger for my 510.( has the rubber sleeve instead of screw on socket ) While looking to purchase a KR808d1 batty I seen where several listings were stating that the universal usb charger would work for 510 or KR8 battys. How can these 2 battys work on the same connection?! The 510 has a female connection and the KR8 has a male connection, the charger doesn't use threads; but it still has to mate with the battery for a proper -/+ connection right?