Canon CH910 (CH-910) dual battery charger / holder for XL camcorders (p/n 3036A004AA). The CH-910 holds two battery packs and can charge them one after the other.
Once the batteries are charged, the CH-910, with batteries in place, can be clipped to your belt and then connected directly to your XH A1. This will give you twice the recording time of just one battery. It can be used with any combination of Canon BP-900 series Lithium-Ion batteries.
For the GL2, XL1S, XL H1A, and XHA1s