We use the anton bauer dionic pack for the xlh1 usually, and i saw that the battery that comes stock with the xlh1 is at 7.4v with 5200mAh... We also own an old GL1 and have bunch of canon batteries from that, and was wondering if these would work with the XL... These batteries are at 7.2V 3000mAh, i'm wondering if the .2 voltage will make any differences or could possibly damage the xl?

No difference, 7.2V (or 7.4V) is nominal. Fully charged is about 8V, discharged is about 6.5V
HTH

The manual reflects all of the battery model numbers that are compatible with the h1. Its a couple pages before the index, where the accessories are listed.