The Xtar and Pila battery chargers are the top two available to us vapors. You can't do better.
You also can't go wrong with the AW brand, many mod manufacturers require their use or the warranty is voided, that is how dependable and safe they are.
You can get a battery charging bag if it will help you sleep at night.
I would recommend that you get a simple volt meter like this
510 Voltage Indicator Rev 2 to check your battery's voltage coming off the charger and when you remove it from your device. A freshly charged battery should read 4.1-4.2v, no higher. A drained battery should read 3.4v, no lower. You can also check your vaping attachments ohm rating for accuracy "under load" by putting it on one end of the meter and the other connected to your device as shown in the picture.
Batteries can feel warm coming off the charger, but should never feel hot. Remove batteries from a charger as soon as they have finished. Check the skin insulation on your batteries from time to time to check for tearing or missing skin. Make certain that both ends of the battery and the battery contacts in your device are clean of corrosion or dirt, clean with alcohol if need be.
If your device's power switch protrudes, disable it from firing to prevent accidental firing such as in a pocket or purse. Do not allow loose batteries come into contact with metal, such as loose change or keys, in a pocket or purse. Buy plastic battery cases to store or carry spare batteries.
Battery case
Use common sense with batteries and you should be fine and safe.