The NuCalm CES device can go through 9v batteries like the Cookie Monster goes through chocolate chip cookies. We have had calls on a number of technical issues concerning the CES device. Almost without exception, the troubleshooting singled out the source of the problem: defective batteries. Due to the inconsistent life and quality of even major brand name batteries, we now recommend the EBL charging stations and batteries. It comes in various configurations, and we recommend purchasing 2 batteries for each NuCalm system so you always have a fresh battery ready. If you are a clinical user and have more than 2 NuCalm systems, You can go with EBL’s carousel charging station and purchase the batteries separately. All configurations have an LED indicator that indicates which batteries have a full charge.