SmokeStik ULTRA BatteryIt uses standard eGo style 510 threading. With 650 mAh (milliamp hours) your ULTRA battery will easily stay charged all day under normalaverage use. Average use is considered the equivalent of smoking a pack of traditional cigarettes a day. The battery will arrive partially charged so you can try it as soon as you receive it. You may need to take the battery out of standby mode, i.e., turn it on. This is done by clicking the button 5 times very quickly. It will take 3-4 hours to fully charge an ULTRA battery. Although it is not recommended that you ever leave an electrical device charging unattended, it will not harm the battery if you leave it plugged in overnight. The battery has an overcharge protection circuit to prevent damage. The ULTRA battery also contains several other safety features. Below is a list of all the ULTRA features. The SmokeStik ULTRA Battery Pink is a lovely pink pearl color just like our Pink Classic battery. The SmokeStik ULTRA Battery Black is a black enamel color, just like our Jet Classic battery. The SmokeStik ULTRA Battery Silver is a high tech stainless steel just like our Pitbull and Hendu Classic batteries.