WeAllHaveWings that does sound very rational, it's good to hear about people looking into things properly.
ECITA are currently working on a British Standard for ecigs and have promised to include protective circuitry built into all batteries on the market.
Meanwhile, general advice to vapers is to be safe, ideally use a battery that charges via a standard micro USB charger, e.g MVP, eleaf iStick, because those do have the protective circuit built in.
If you use one that you screw the business end of your battery in for charging, make sure it says OUTPUT 4.2V, 500mA (0.5A) and don't plug it into any mains charger that is over 500 mA (see pics) and, of course, buy from a reputable source.
A big problem is that USB is no longer a standard. The newer chargers, for e.g. 2A Apple device chargers, are rated at a much higher current than lots of other things that can be plugged into them.