As AndyC says rule #1 of vaping is never buy from ebay, rule #2 of vaping is never buy from ebay ....
there are some people on ebay selling good quality kit, but they are absolutely drowned out by the squillions of ebay sellers selling god awful cheap tat, and all of the ebay sellers are bending ebays rules (you're not permitted to sell e-cigarettes on ebay at all as per their policy.)
I get at least 30-40 spam emails a day from "less reputable" Chinese sellers offering me eGos (and all kinds of other stuff) at really really cheap prices. Usually they do not contain the battery inside that they claim on the outside (they might have a 350mah battery and not the 1100mah battery it's supposed to) or the battery inside is low grade and isn't going to last long or the battery inside is actually a capacitor and not a battery at all.
The vast bulk of eGo blister packs sold on ebay fall into this category of cheap tat.
The brand name eGo batteries that are definitely decent are Janty, JoyeTech, SmokTech AnyVape, Vision, and also Kanger. If it has anyone elses name on it I wouldn't touch them with a long stick. they might turn out to be fine, they probably won't and it's a bit of a lottery.
As far as charging goes, charge them from a charge cable plugged into a wall socket, and do not use a plug adapter higher than 1A.
When fully charged a 900mah or 1100mah battery ought to last about a day of normal vaping.
If the light on the charge cable goes red when the eGo is attached and it's plugged in and takes forever to turn green, it's not charging right and a new cable is probably in order. Check the output voltage stated on the cable. It should be 4.2V 420ma. If the numbers are smaller than that then you could have a cable that's designed to charge the much smaller cig-a-like batteries, which would be limiting the current supplied to your eGo and means they'll take forever to charge. (cig-a-like battery chargers run at about 180ma)
Also USB sockets can fluctuate how much power they. It's even possible to ruin a perfectly good computer if something goes wrong. Charging in a wall socket is much much better.
If you plug the eGo into the cable and the light stays green and it doesn't charge then there's a problem with the centre posts contacting, either pull the post (as in video upthread) or clean the contacts. A red light on the cable and taking forever to charge means not enough power is getting to the eGo to charge it correctly, or the battery inside it is borked.
If your ProTank is spitting juice into your mouth it's flooding, which is usually caused by not enough airflow coming into the tank so when you draw on it it pulls to much juice into the head.