Barry I recently bought a Pearstone dual charger from B&H and it charges up the genuine M series on the 12v DC cig socket in the truck no problem, which is why I bought it, but it comes with the US AC wall socket cable so you have to get an adaptor if you want to use it on the mains, or go to Tandy or Radio Shack and get a replacement cable. (the most unexpected thing was that it was not supposed to be used on 240V AC according to the specifications on the web but on the back of the unit it has the usual 110-240V AC 50-60Hz notification so it must be like the Sony units, automatically sensing an switching, it has the same horizontal 8 style two pin socket for the wall cable, you could use the Sony cable in fact).
You can charge any camera battery I guess if you get the matching interchangeable adaptors, they slide on to the charger, a little too easily actually, (no positive lock button) they tend to come off the charger with the battery when removing them unless you hold a finger against the back edge of them.
It has an LCD screen for the readouts (percentage of charge as it charges) one readout for each charging location, the left hand readout tends to do some weird jumping and flickering because it seems to be stuck on the readout for the USB docking carge rate and doesn't automatically switch over to the battery readout if you put a battery on the left charging station.
Altogether a handy unit for me though as I now have a means of charging batteries when or if I'm on the other side of the black stump. I've already given it a test run, I had to charge up two new NPFM500H's I got to replace the two original NPFM55H's (now deceased) that came with the A100, it charged a camera battery up to 100% running off the car battery in a few hours and didn't seem to affect the car battery at all, it still started the truck as if nothing had happened.
I think you have to be careful with the Sony standard charger, I don't think it has much in the way of sensing and regulation for the camera battery, the more expensive Sony ones might be a better idea but Sony of course charges like a wounded bull for those.
As far as camera batteries are concerned I have never used non genuine ones, I have heard too many stories about how useless they are so I get the genuine jobs, I got two genuine NPFM500H's (along with a couple of other items) from B&H for about the same price as one genuine battery here in Oz, and that includes the airfreight charges.