Both are the same LIFE batts, A123 is the company that makes the ones in a metal cylinder which are called the original A123 LIFE batts, they are slightly better that the flat packs, both dry, no gel in them like LIPOs, some times you are in the need of a flat pack because the round ones will not fit in your jet like in my Reaction 54 nose.
It is up to you to charge the batts in your airplane or out side, I do out side because thats what I do, and I mount my batts in a way that they can be removed at any time, your choice here, they are not LIPOs.
We use both, most jet guys use the ones made by the A123 company ( cylindrical ones ) we use something like 30c discharge in case there is a high voltage demand at any given time, we also use two batts for the radio with two switches as a redundancy in case one pack or switch fails, ultra rare in jets, happens more often in gassers because of the vibration they produce.
All in all, always keep an Eagle eye on your batts when charging, every time, that should keep you out of trouble from a bad batt pack, I have removed one or two packs from service in the last two years because one cell from a two pack batt was taking way too long to come up in voltage, always know what your batts are using per flight, I use the same charger for both and my charger is not a fancy one, it's your regular 4 bottom one.
Hope this helps.