The old style chargers use a rectangular plastic connector between the AC adapter and the Charger unit itself. The new style (V2 or Version 2) use a round connector much like a headphone jack. Here's a picture of the two different types of chargers.
These Maglite Charger systems also come with (optional) 110V AC and 12V DC chargers. Each of these charger adapters has also been updated to the round type of connector. If you have an old-style Maglite Charger system and the charger unit has a rectangular connector, and you need to buy a new 110 V AC adapter for it, you will have to get the Universal Adapter to connect the two together.
I will try to outline the part numbers and compatibility below.
ARXX035 - AC Converter (OLD) - Discontinued
ARXX195 - AC Converter (V2 - NEW) - Replaces the item above
ARXX025 - Charging Unit (OLD) - Discontinued
ARXX185 - Charging Unit (V2 - NEW) - Replaces the item above
ARXX045 - DC Power Cord (OLD) - Discontinued
ARXX205 - DC Power Cord (V2 - NEW) - Replaces the item above
ARXX228 - Universal Adapter - Allows interchange between discontinued and new Charger versions
Here is a picture of the Universal Adapter. It can be used to connect any old to new versions. Two "pigtails are included - One to connect old charging units to new power adapters and one to connect old power adapters to new charging units.
I hope you have found this post to be helpful. Please visit our website at http://www.maglitesales.com .