Would love to see a mod that adds a function for recharging fusion cores. Seeing as how they are a fairly finite resource, either having to shell out a bunch of caps at several vendors or taking on sentry bots just to get your hands on a few can become quite tiresome. Because of this I'm never realy willing to use the armor unless I know I'm about to fight something that'd beat me to death with my own arm otherwise, or if I'm heading into The Glowing Sea for loot reasons. And once you have the gattling laser your fusion core problems become even greater.
Thus I bring these ideas for a meathod of repleneshing those rare pre-war batteries in just two steps.
-First, that once a fision core on your person is drained via armor or weapon it returns to your misc. inventory as a Drained Fusion Core. This would be the item needed at the later to be mentioned Fusion Charger to create new Fusion Cores. (If the modder is really brave he/she could also make the Drained Fusion Core a regular spawning item for looting at military sites and such)
-Second, the afore mentioned Fusion Charger. This would be an item one could build at a settlement, requiring a comparitively large amount of power to operate and a high level of the Science perk (say 3 or 4) to build. As well as a large amount of the rarer building items such as nuclear material and circuitry.
The number of way this could be added to the game make to make it lore friendly are numerous, sure you could just add it to the existing build menu but where's the fun in that? Make it a blueprint you have to find in a remote facility, maybe in The Glowing Sea itself. Its location hinted at in a computer terminal the Lone Wanderer finds in one of the many research facilities that seem to litter the commonwealth.
I'd love for any other ideas and hopefully a modder to fall in love with this and make it real.