All instruments use custom made Alkaline batteries, except the LISST-Portable that uses rechargeable Nickel Metal-Hydride (NiMH) batteries. The main batteries used in the LISST-100 and LISST-ST are identical, with a +/- 15V-output and 14A-hr capacity. This battery can power the instruments for well over 6 months. The LISST-ST uses an additional rechargeable Lead-acid battery to power the door motors. Note that the LISST-100 and the LISST-ST instruments were both discontinued in 2005, but batteries for these instruments are still available. The LISST-100X and the LISST-STX, both introduced in 2005, uses a +/- 9V custom battery. The batteries can be purchased from Sequoia. If you would like to wire up your own batteries, please contact us for a battery drawing. The LISST-25 uses 4 standard 9V alkaline batteries.