I just got into using an Ego recently. I bought 2 knock off
batteries and one Joyetech. Both of the knock offs completely died within 3 days of getting them. 2 more were sent upon return. One is already acting funny (blinking LED when it's charging sometimes, not charging at all sometimes, etc.) The other one's center post is in a very odd position, I've tried to correct, but it goes back as soon as I put a cart on, and no, I'm not screwing it in too far, it's just so flimsy that contact moves it. And the switch on it sticks often and it stays on even after releasing it.
The Joyetech has never failed, and it use it most. The switch on the Joyetech is way nicer and made completely different than the knock offs. The battery contact is made way better than the knock offs. The threading is better than the knock offs. Comparing them side by side, you can tell the Joyetech is better quality.
Not to mention that the Joyetech outlasts the knock offs, even though the Joyetech is a lesser mAh battery than either of them.
Perhaps some of the knock offs are made in the same factory as the Joyetechs, I don't know. But if the ones I have are made in the same factory, they sure as heck are not made on the same lines, because they are NOT the same.
Not trying to start a debate, but if the OP want's advice on what to buy, I'm just telling my experience being a new Ego user myself. I will never buy a non Joyetech product again.
I used knock off and real Joyetech 510XL
batteries for a good while and had good luck with both the knock offs and the Joyetech versions. However, I did get a knock off charger (correct output, etc.) that would kill a battery in a second.
