Smart solar pathlight (not holding charge)

I have had lights for about 6 months. I feel like I have a defective solar pathlight, all my lights are 100% charged/remained this way for awhile (have 11 in total). One light couldnt hold a charge and even died fairly quickly after charging in outlet and placing back outside. I thought the battery was the cause, bought a new battery/panasonic one, but its been two weeks and its 46%. Then thought it was the location although was fine in winter (currently some part of the day in shade when there is sun). I decided to try and swap locations to a full sun/unobstructed location of another pathlight. Its odd that all my other lights are fine and are at 100% (and even the pathlight that swapped to part day shade location remains at 100%). The light setting is 30 sec turn off, only 8pm to 1am light schedule. One notch below full brightness. No motion sensing. Unsure if Im able to get a replacement? Also almost all lights the top is separating but the lights seem to be still holding charge fine.