In addition to charging and maintaining all 12V GILL sealed or wet cell (filler caps) aviation batteries users can now determine the level of charge remaining in their battery, and if weak and in need of replacement, before going bad. Units test for weak/dead cells and will recover weak or severely discharged batteries that other chargers would reject. Known as the CEC2-AA series they feature advancements in easy to understand battery analysis and condition not previously available in any other single model. Their high efficiency design, controlled by industrially-rated microprocessors, allow continuous operation (24 hrs/day). Temperature sensors prevents over/under charging from freezing to 130-F.