In my search for a connector for the Joye 510, I came across this. I was basically taking apart all the threaded connections in my apartment, testing the threads against my 3 models of PV, then putting them back together.
I came across the car adapter for the DSE chargers - that cord that hooks up your DSE charger to your car cigarette lighter.
Here is the end I am concerned with
If you unscrew that metal ring behind the tip, you get this
Now that little tip will come out and you'll have this
The larger of those two parts fits the 801 thread nicely and should make a good negative connection. The smaller of the two parts could be a positive center pin with a little imagination and insulation. I did a quick test by wrapping that smaller piece in a piece of crafting foam I got at Walmart for less than a dollar, then wedging the wrapped part into the outer part. Here is what it looked like afterwards. That brown that you see is the foam I used.
At this point I tested it with my multimeter and got no continuity between the two parts.
Here is a picture of it attached to my 801 atomizer. Sorry, I took these pics before I wrapped that little pin in foam to hold it up inside where you wouldn't be able to see it. You can see that it leaves a little more space to work with than the part salvaged from a dead battery.
I would suggest though, soldering the positive wire on before insulating the two parts from one another. Once you have it insulated, that center pin would be pretty hard to get at with a soldering iron. I think that epoxy or silicone glue might work as insulators also, but haven't tried them.
It will be a while before I get around to making a mod with this, if I ever do - 801 is not a favorite for me - so please feel free to use this info, make some mods, post some pics for us, whatever. I just wanted to share the info right away.
Another couple tidbits of info, semi-related:
There are other car chargers out there with a metal connector thing like this. I don't own one, so I don't know if they will work or not but it might be worth a shot.
These adapters are for sale for $2 each at Ruyandirect and they also have good prices on other PV stuff that might make it worth the wait to get the savings.