All batteries, while similarly shaped, can be very different. What you need to pay attention to is the "mAh"(milliamp hour) which refers to how long your batteries will last and the general "Amperage" of your batteries. There are plenty of detailed information sources out there such as Mooche's Blog Page which you can find here https://www.e-cigarette-forum.com/blogs/mooch.256958/. But in Simple terms, The more mAh your battery has the longer it will last, while the more amperage your battery puts out will determine how much power your device can safely put out, so if you want to vape anywhere from 120 watts or higher you want a higher Amperage battery.
Types of external batteries: 18350/18500, 18650, 20700/21700, & 26650
Some Important things to keep in mind when it comes to properly handling your external batteries(any battery that can be removed from your vape or was not pre-installed into your vape by the manufacturer) is to follow general safety rules.
- You never want to charge an external battery inside your vape, when charging batteries, they have constant power being put into them, which generates heat. Without a way for those batteries to get the proper ventilation, the heat can shorten the life of the battery or physically damage the battery(dont use batteries that have expanded)
- You want to make sure the battery wrap is not compromised in any way. The wrap will be different depending on what brand you use, they can be green, blue, purple, brown, some look like some company just put a branded packaging wrap around it. NEVER peel these off or use them if the wrap has been damaged.
- Never carry loose batteries in your pocket, bag, or car(the heat situation applies here too if you live in a hot area). You want to carry your batteries in a case, pouch, or any type of individual container that does not have any lose change or other metal materials. You also want to avoid the batteries touching negative to positive in your pocket. These situations can cause your battery to short if a connection is made in your pocket, bag or car which will result in either a fire or explosion. Batteries for all different uses are safe until mistreated, so please take care of your batteries and transport them responsibly.
- Avoid Making contact with liquid, if you have a vape with a magnetic door that covers your batteries, check it regularly because vape juice can sometimes seep into the battery bay, which will cause a short with the same potential for consequences as the previous bullet point. All liquids apply to this.
- Keep your batteries matching so you don't have any unexpected power surges or shortages from one of your batteries. You'll also have your batteries last longer and have to charge them less often seeing as how they will discharge at the same rate if the two batteries are the same.