But that is just cycling the batteries and wearing them, which seems unnecessary if a charger can be running? I would hack the Inteli Power PD9155 to increase the float voltage, or put another charger in parallel once in a while to give a correct top up charge.

 

But that is just cycling the batteries and wearing them, which seems unnecessary if a charger can be running? I would hack the Inteli Power PD9155 to increase the float voltage, or put another charger in parallel once in a while to give a correct top up charge.

Certainly it would be cycling the batteries. THAT is why my suggestion was, and still is, to put the batteries and the power converter in parallel, but with diode isolation. That allows the battery portion to stay at full charge and be instantly available to take over if there is a mains failure. The only down-sides are the diode forward voltage drop and the need for a separate small float charger.