I can't find enough Electron Charge Packs to keep him happy! This is my first Energy Weapons playthrough and I've been hoarding all the ammo I can till I got my Gatling Laser. Unfortunately, I burned through all of it in one cave dive, lol. I've cleared out the Brotherhood so I can't buy any energy weapon ammo there, any clue where I can get more? Its totally killing my Enclave role play

Places I've already raided for ammo --v
Brotherhood Bunker
Silver Rush (Left them alive, but they don't have much ammo)
Sierra Madre Casino and its surrounding area
All of New Vegas
Victors House

You could always kill fiends for some ammo.
Also don't forget that you can "convert" other energy ammos into ECP.

Of course, but the problem is I can't find ANY Energy Weapon ammunition.

I always thought the Van Graffs at the Silver Rush sold enough. Or the Brotherhood, but you already wiped them out.

Yeh I sided with Mr. House so I had to wipe them out... Van Graffs don't sell ANY and I really don't feel like waiting 72 hours at a time to get more ammo... It kinda ruins it.

The quartermaster at Hoover dam usually has a large supply of every ammo type (maybe just the first time you meet him though).Have to have a high speech (50 or more?) or bachaler perk to convince him to sell to you.And usually replenishes after several days.....also the 188 outpost has some types of energy ammo

Thanks! I'll try the Hoover Dam one.