Inspiron 5150 Battery question

Hi to all.  I have an Inspiron 5150 Notebook that was just repaired (thank you extended warranty!) with a new system board.  The problem was in the power supply/charging circuit. 

I have 2 batteries, one is almost new and is fine.  The other causes the powewr lights to indicate a defect. ( rapidly flashing amber-amber-amber-green), yet the battery charges and functions.  If i keep this battery, will it harm the new mother board circuitry?  It holds a charge for almost an hour...if it's going to damage something else I will chuck it, if not, it seems a waste NOT to utuilize it until it finally expires

 

Thanks in advance and best regards

Morey

I5150 P4 3.06GHz  1GD RAM ; 40GB HDD ; Win XP Pro SP2 ; CDRW/DVD COMBO