I was assuming your recommendation was based on the notion that it's galvanically isolated. Because otherwise, if it can't be used in a permanently charged state you'd be inviting a whole bunch of other issues, like voltage drops when depleting the cells. So how does the XT behave when nearing a full discharge, will it cut off or just keep discharging? And did you measure voltages while discharging? Is it built to maintain 12V (+-tolerances) throughout its rated capacity?