backup battery

[yoloflyer]

I'm about to upgrade the Sport SX that I installed years ago to an HXr. When I installed the Sport SX I also installed the Power Safe backup battery for backup power. On the EFIS Accessories documentation web page it indicates that this backup battery is for the Sport SX only; the TCW backup batteries are recommended elsewhere as backup batteries for other EFIS systems. Is there any technical reason why I can't continue to use my current backup battery as a backup power source for the HXr display?

[GRT_Jeff]

The HXr uses a lot more power than the SX so it can drain our battery fast and not give you enough backup time. Our battery is 2.2 amp-hours. TCW has higher capacity batteries.