What is the meaning of these?

UAAPU is an acronym for Under Armor Auxillary Power Unit. An APU is a fuel powered generator which provides electrical power when the engine is not running. On the M1A1, the APU (when fitted) is carried externally in the turret bustle rack. This is the box which sits at the left rear of the turret in the rack. On earlier M1A1 variants, an external APU (in a different form) may be carried at the rear right of the hull.

On the M1A2 SEP, depending on the upgrades, the tank may carry the internal UAAPU or a Hawker battery system (A high capacity battery which replaces the UAAPU to provide electrical power). Where the UAAPU is fitted, there is a small exhaust port on the upper left of the rear hull plate, between the left tail light and the engine grille. Where the Hawker battery system is retrofitted to a tank which previously had the UAAPU, the exhaust port is blanked over.

PS: I believe you mean M1A2 SEP

That was very helpful and enlightening Phil. Yes I do mean the M1A2 SEP. Another question would be, was the Hawker battery and the UAAPU both used in Irag during the OIF?

Yes, both the UUAPU and the Hawker Battery System have been used in Iraq.  It depends on the unit and how new their SEPs are.  The UUAPU was not that effective and was replaced by the Hawker system.  Depending on when the unit received their tanks and if they have been rebuilt or retro-fitted with the Hawkers.

HeavyArty

Yes, both the UUAPU and the Hawker Battery System have been used in Iraq.  It depends on the unit and how new their SEPs are.  The UUAPU was not that effective and was replaced by the Hawker system.  Depending on when the unit received their tanks and if they have been rebuilt or retro-fitted with the Hawkers.

Thanks HA. I am particularly interested in the !st Armored Cavalry. Was it UAAPU or Hawker for their tanks?

Yes, depending on when.  1 CAV has been to Iraq a few times since '03.  Sorry, there is no clear-cut answer.  Either way is correct.

HeavyArty

Yes, depending on when.  1 CAV has been to Iraq a few times since '03.  Sorry, there is no clear-cut answer.  Either way is correct.

Thanks again HA. As I always say, "Got to the Expert".