Today my boss called me to say his 950mah (or what ever it is) ego died suddenly, early morning still. He forgot his spare at home, do I have either a charger or a spare ego bat by any chance? Why yes I do!! I have a little 450mah I use as a last resort. I hook him up til he can get to vape shop to buy a new ego. We'll wouldn't ya know a few hours later my 18490 in my Provari gave out!! Weird as heck !! But like I said, back up for my back up, I had a spare 18490 fully charged in my purse safely wrapped and ready to go. I also have a small CE4 (last resort) and a new head for it and I have a spare coil for my Protank.