Charger is way better, I get better range out of my 40's, I had some problems with losing the collars at 1st but I just changed the communication setting and have not had a problem since, I run Garmin and Marshall systems on my dogs and with the 40 collars you can put both recievers on 1 collar.
I just got an astro 220 with dc 40 collars. Mine get to .8 miles and lose communication. Should I be getting more range than this? If so, what communication setting do I change to?