Okay, so for my tabletop RPG before I relinquish the codes for the Energy Weapons Armory Cache to the players I got to thinking of the size of the ammunition for each type and possible number found in pallet form outside of the normal ammo boxes or other containers.

Below are the links and I appreciate all input...

http://fallout.wikia.com/wiki/Category:Ammunition

http://fallout.wikia.com/wiki/Electron_charge_pack%C2%A0

Now for the Energy Cell standard for most Energy Pistols and Plasma Pistols they appear to be almost the size of AA batteries tiered together which would fit in the palm of hand no problem. For the number found in a pallet I was thinking maybe ten to a box with x-boxes in the pallet.

Now for the Microfusion Cell appears to be about the size of a D cell battery. Eight to a pack with x-packs in the pallet.

Now the Electron Charge Pack looks about the size of a 12oz can of soda or similar beverage... or maybe the size of an replacement oil filter for a vehicle. Six to a pack with x-packs in the pallet.

I have several ways aside from the New Vegas recycling of energy ammo for the players to recharge used cells or create new cells with the aid of a pre-war prototype machine that takes Fission Batteries and uses them to make x-number of new cells.

Another is a post-war invention using tiered Fission Batteries, scrap metal & electronics to recharge the cells.

Yet another uses Fission Batteries in a harness and wires from Scrap Electronics to jury rig an almost constant power supply to the weapon.

Fission Battery

I know in gameplay and canon lore that the Fission Battery has no purpose in weaponry other than a few schematics and recipes but I could foresee the USA government having some weapon project like a Heavy Laser Rifle/Cannon that with an equipped Fission Battery multiples the damage of the beam or something.... thats why I created a few homebrew weapons and the aforementioned uses

The sizes seem about right, although the ECP seems to change size depending on if its slotted into a laser RCW versus a Gatling Laser. I would go with the RCW size, since it seems more in line with the other ammo sizes. For recharging the cells I'm not really sure what would work best, since the amount of power the fission batteries can give off has been a bit inconsistent. There's times where it can power pre-war systems for hundreds of years, but when you try to put some of that energy into your laser pistol you only get 25 shots. I suppose a big part of that is game balance though, and if you're worrying about how much juice the batteries would put out, I would make it a pretty low but constant amount. You would have to sit there and wait while you're recharging your cells at a safehouse, but hooking up a harness of them should require a lot of batteries to get a good amount of power out of it, and not to mention the high repair and energy weapons skills you would need to create it.