My EQ6-R Pro draws about 1.7 amps when slewing, and around 1 amp when just tracking (22lb payload controlled via EQMOD, no hand controller connected). As mentioned above, the EQ6-R Pro behaves erratically when the voltage drops below 12v. I never tried my Tallentcell on the EQR-6 Pro as I use a large LiFePO4 battery to power the mount, cameras, hub, laptop, etc.
In general, Tallentcell batteries are great and I actually use the 11,000 ma/hr version for my CPC1100. I put a velcro strip on it and slap it on the side of the fork. It works for several hours on outreach night and I don't have to contend with wires.
As others have mentioned, the Tallentcell may be too anemic to reliably drive the EQ6-R Pro.