Lithium ion rechargeable batteries are dangerous. It's dangerous to vape on them. The typical round cells we use for vaping never were designed to be used outside a fully protected battery pack with a protection circuit. There are no hard and fast numbers that either are safe or are unsafe to vape. The CDR number was not picked because it is safe. Rather, the number was picked because, based on the data gathered from rigorous testing and based on in-depth battery knowledge, it just seems like a reasonable number to recommend to new vapers to start. When we vape we don't discharge the battery continuously. Rather, we take one hit, which causes the battery to heat up internally until we release the fire button, after which we give the battery time to cool back down again. The longer you wait between hits, the more time you give it to cool down. If you take a longer hit, then, for reasons that are obvious, the battery keeps heating up for longer, reaching a higher temperature as a result. In addition, if the resistance of your coil build is lower, then the battery heats up faster. Whereas choosing a battery with a higher CDR causes it to heat up slower. So the main enemy is temperature, and, by knowing how to balance all these factors (the duration of each hit, the wait time between hits, the resistance of the coil build, the CDR of the battery), and also by taking some additional factors properly into account (some of which are unknown factors, or they require the user to know and understand the added risks before this same user can then decide for him/herself on whether it will be still acceptably relatively safe enough to proceed or not...), advanced mech users can still vape on a mech using coil builds that aren't considered within reasonable safety limits if you are new to the mech, and that therefore should not be recommended to anyone. Among the main risks in this regard are the potential risk of an accidental long button press, the potential risk of the fire button getting stuck and not knowing how to safely disarm the mech in the possible event that the fire button does get stuck. Also, there's the potential risk of making a wrong assumption about the true CDR number (the numbers printed on the battery wraps and the numbers listed by the battery vendors usually are wrong numbers), or getting a fake battery the CDR of which is much lower than the CDR number that is listed in Mooch's Test Results, Ratings, and Performance Tables. Just to give a few examples of what "taking some additional factors properly into account" usually means.
