B is the black version. Without B, the white version. It works perfectly for me with the panel, but the first winter with sub-zero temperatures is still to come. However, the camera can easily last a few months when it is fully charged.

Isn't "B" just "black"? I am not sure....
My cameras charge flawlessly and have runtimes that have surprised me. approx.3 months in winter, approx. 5 months in summer