Originally Posted by Tom G.

It's really a power supply, not a battery charger. Power supplies provide a steady & constant voltage which is needed during programming (13.2~14.5V depending on control module). Battery chargers are not meant to be used as power supplies as they frequently send power spikes and unregulated voltage, which can instantly brick the module (or modules) you are working with.

Here's the one we are using, they are not cheap:

Official Fronius USA Site

Again, do not use a battery charger.