Take precautionary measures to ensure battery safety, especially if you are using the 18650 vape batteries. Don’t use a charger other than the one recommended by the manufacturer; don’t overcharge or over-discharge the batteries; store the batteries which are not in use in a safe place (preferably in a plastic case); and don’t carry loose batteries in your pocket.
A disclaimer here: I am not a professional in this field. The symptoms I describe below and attribute to either to under or over dose of nicotine are information I have assembled by reading web sites and published studies; my advice is based only on that. I can not promise that they are absolute indications. Above all in your process of switching to vaping, listen to your body. If you can work out what it is telling you then that’s the best advice of all. vaping