How deep is the Sirius discharging it? The mAh ratings can get a little misleading since different discharged voltages can be used to come up with it. The Sirius may be taking the battery down to a lower voltage than the Accucycle or even what the manufacturer used for the rating.

If I'm not mistaken, the Accucycle Elite uses a discharged voltage close to what most common receivers will still function at. I'd have to read the manual to verify that though.

On the same subject, I recently bought a number of 4-cell Spektrum 1100mAh ni-cad receiver packs and decided to charge and cycle each one. All of them have shown 1300-1400 mAh according to my Accucycle. I wonder if a conservative voltage was used by the manufacturer when rating the battery capacity? Most other batteries that I have bough usually perform slightly worse than their claimed capacity. We'll see if the Spektrums keep up this performance as they get used.