Advanced Personal Vaporizors (APV) and "mods" typically have user replaceable rechargeable batteries, but these are not the same as the household rechargeable batteries that you use in your remote control. Some precautions should be taken when using these larger batteries, while battery failures are rare they can happen. This can occur if the battery is poor quality, it doesn't have short circuit protection or has been damaged in some way. If you are using one of the many new "advanced" devices it will typically have electronic safety features built in, but if you are using a "mechanical" device with no internal electronics then extra care should be taken in your use of these batteries. You might also consider using a short circuit fuse like the VapeSafe or the ShortStop for added protection. It is also recommended to buy a high quality charger and a volt meter for testing. Take some time to educate yourself about the safe use of batteries in your APV.
Warning: many of the batteries available online at a discount could be counterfeit and poor quality. Buy your batteries from reputable vaping suppliers, avoid websites like alibaba and other "wholesale" sites. Do not buy cheap batteries, it's not worth the risk just to save a few dollars.
For a more in depth look at batteries and battery safety please refer to this article from EcigAdvanced
For an extremely in depth look at battery safety read this thread on ECF