TETRA chargers can be adjusted to any type of 12V or 24V batteries. They serve best when using lead batteries with liquid electrolytes, AGM, Gel and start-stop technologies. These chargers can run in two modes – automatic or manual charging. The automatic, micro-processor-controlled setting constantly analyses the battery and stops charging when the battery reaches 100%. Opting for MANUAL, the user will have full control over charging. The F-2914 and F2920 models also come with ripple-free functions and enable charging while the battery is still connected to the vehicle, preventing memory loss to the vehicle's electronic equipment.