hi , my focus goes from November 1st to April 1st to hibernation. In the 5th months the battery should not be unloaded. That’s why I am thinking of buying a battery trainer and then having connected it completely to the current and it always recharges and discharges the battery. It usually charges with 300 mil A and discharges with 100 mil A. That’s not much. Is that enough to bring the battery well through the winter without causing damage and thus flurid or What do you call it? Is it enough to disconnect the mass cable or do I have to disconnect it completely? In the appendix, a LINK from the selected device :www.ebay.de/itm/12-Car-Car-Battery Trainer-Battery Charger-NEU-94132/250900750853