The Newest from Bishop Rotary & Critical .The battery will sit even more flush with a low profile for better balance on the hands without the top weight. These battery packs are made to be used with the RCA Power WAND, if you’ve purchased that machine separately. Available in two sizes – the Standard, which provides up to 10 hours of tattooing time with 1500 mAh, and the Shorty, which provides up to 5 hours of tattooing time with 800mAh. The batteries will work with most USB-C cords and charging bricks if you do not have the Critical Charging Dock (dock sold seperately) Compatible with all Critical Connect firmware and hardware – including the Critical Connect Footswitch. A note regarding the readout on these batteries: if you see the battery percentage fluctuating, the battery is calibrating to provide you with the most accurate battery life read-out and has no effect on the functionality and run time of your battery/machine. Tier 1 grade battery used to make this power pack. Batteries are shipped partially charged – they do not require a full charging cycle but will need to be charged upon receipt. After powering on, initial battery life display will take approximately 5 seconds to calibrate to an accurate read-out. You may notice the battery life adjust (increases or drops) between activation and pauses during sessions – this is because the battery calibration is reflecting the device’s current usage scenario. Note the percentage difference may be more noticeable on the Shorty batteries due to the smaller battery capacity.