This has been something thats been kinda sitting in the back of my mind since I bought my eGo, I didnt do huge amounts of research and bought a slightly unknown brand of battery. it should be ok as long as I am not doing stupid .... with it or over using it untill I buy a mod or something, right?
I bought this if it matters, should I be throwing this thing away immediately or?
Happy Ego 1100mAh Battery, Black
The question you need to answer is what circuitry is inside the battery, and you can't ever answer that, even for the good brands. It's just that good brands are more likely to have good circuitry.
A good charger (and there's another variable) supplies 420mA at 5 volts. A lithium battery requires no more than a certain current. That current will always be above 420mA. So if the charger correctly limits it, then that's OK. But as a battery charges, it's voltage increases. If it gets to 4.2 volts, it's full. If it gets above 4.25 volts, then it's over-charged and getting damaged. That's a margin of error of only 1.1%, which is very close for electronics, where margins are generally 5% or more. A very cheap battery may just depend on you disconnecting it when it's full, and not bother limiting the voltage at all.
Then there is another protection circuit that has to allow the battery to supply its full capacity and then switch it off before it gets too low.
If either of these circuits is substandard or can get damaged or is entirely missing, then the battery is in significant danger of exploding.
We have no way of knowing what circuitry is in any battery and it would take an effort and expensive equipment to test any charger. We do know that for a manufacturer, every added electronic component reduces profit.
So we buy from companies that have good names, because they don't want to risk losing that good name.