Sept 12 (Reuters) - Southwest Airlines ( LUV ) said

Friday it will require passengers to take out removable lithium

batteries from powered wheelchairs and scooters before boarding,

citing fire risks.

The new rules take effect Sept. 25 and Southwest ( LUV ) in January

will impose new size limits on lithium batteries. On Tuesday,

the Federal Aviation Administration issued a safety alert to

airlines over risks from lithium batteries in aircraft passenger

compartments, citing a large number of serious incidents.