#1 mobo, EP-8RDA3+, unused for the past six months and has a dead CMOS battery (keeps getting checksum errrors.) #2 mobo, two years old, went the last year without being plugged in, and the battery was dead when put in the EP-8RDA3+. #3 mobo, very old (4 yrs old) that I use once a month, has always been plugged in, and has never given me problems. Battery solved the checksum error when put in the EP-8RDA3+. Is this proof that the CMOS battery recharges as long as the system is plugged into an outlet?