Same here. I've been using them for a couple of months or more. I started with four of the skinny ones, for the EStix Mako, and one charger. It was taking forever for the larger ones to come in, so I ordered three more of the skinny ones from EStix. Then finally, a Reonaut, sorry forgot who, posted that MadVapes had the larger ones, sized like the 18650 battery, so I ordered five of those. MadVapes didn't have the chargers, though, so I ordered two more chargers from EStix. I think they, charger, are $11.99 each. Last I checked MV they said they would be getting the chargers but that's been a week.
The vape, at 5v, is a sweet spot for me too. Good use for standard resistance atty/cartos, from pre Reo stash.
I only have the one charger, right now, (two new ones waiting at UPS store along with new blk/blk Mini {another advantage of having more than one Reo - waiting for new one doesn't "hurt" as much} and the light on wall brick does turn green. Will report about new ones when I use them.
The skinny, Mako 5v, are loose in the Grand and Woody or Woodvil. Other than making a tube for it, to increase diameter, I use a folded over, many times, piece of electric tape, about 2" long to lay in the battery grove, when I use the skinny ones. Some day I'll make it to the hardware store to see if I can find a suitable tube for those.
It will take several charge/use cycles for the 5v Ni-mH batteries to reach full charge capacity. That's the nature of Ni-mH batteries. Experts of these type batteries recommend running them down really low, once a month and immediately recharging. They do suffer from memory affect unlike Lithium based batteries and cells.
Alice