Can the batterypack BP-199 for Icom T81 be repaired?
 

My batterypack BP-199 has become exhausted after 3 years of little use
(around 25 charge cycles only). Is there anyway that it can be easily
repaired? Can I open it easily and substitute the cells with new ones?
What kind of cells are inside and where can they be bought?

Greatful for any hint!

Harry