Originally Posted by
shurcooL
I didn't really pay much attention to the size when ordering, but it says 145x45x18mm on their site. The battery tray length in B4 is just about 145mm, or just under it. The battery, however, is only 145-146mm at its shortest side. The other side is much longer. In fact, all the dimensions are only valid if you measure at their absolute lowest point.
Send it back and tell them to send you a battery with the measurements that they advertised. Measurements shouldn't be the smallest point of a dimension, it should be the largest. Tell them to make it right or refund your money - no reason to take a loss on selling it used when you haven't used it.