Bulk microfusion cells carry less charge than standard microfusion cells, but are substantially cheaper to compensate. The reduced charge results in 85% damage, but also reduces the strain on the weapon to 85% as well.
Microfusion cell, max charge
The max charge version of the microfusion cell deals the highest possible damage (x 1.5) at the expense of highly increased weapon degradation (x 2.50). Using this ammunition type also negates 10 points of an opponent's Damage Threshold.
Microfusion cell, over charge
Over charge microfusion cells gives a damage multiplier (x1.25) and negates 5 points of an opponent's Damage Threshold. This comes at the cost of having your weapon deteriorate at a faster rate (x1.50).
Added in the add-onGun Runners' Arsenal, this sub-type causes 30% more damage, penetrates armor more effectively, and weighs less than the standard microfusion cell. The only drawback is a slight increase in weapon degradation. It requires Vigilant Recycler and can only be crafted at a workbench. This type of cell is superior to overcharged cells.
Hidden Valley bunker. If you gain accepted status or higher with the Brotherhood of Steel, you will be approached by a BoS initiate telling you they have placed recycled ammunition in a box at the bottom of the entrance stairs to the L1 area. The box will be replenished randomly with microfusion cells, electron charge packs and small energy cells whenever you enter L1, giving a continuous supply of energy weapons ammunition.