A number of years ago I worked for a shop that sold ScubaPro, and the shop put one of their computer models in the consoles of all their rental regulator sets. One weekend I took a class for OW diving, and almost all of them had dead batteries. I had just bought the same model to use as a backup, and its battery died shortly after. The funny thing was that when we changed the battery at the shop, the old one still indicated that it had power. I replaced it anyway, and it failed again a few months later. I stopped working at that shop around that time, and I just stuck the computer in a drawer.
A couple years later, I decided to sell it to someone who could make use of it, so I took it to a different ScubaPro shop to get it going again. They told me that ScubaPro had determined that the model was defective and discontinued it. They had for a limited time offered a replacement model. I had duly registered the computer when I bought it, but I had never been notified, either by ScubaPro or the shop where I had bought it. The limited time for replacement was now over, so I had a non-functioning computer that had no value whatsoever. Even though ScubaPro had openly admitted that the design itself was defective and was the cause of the problem, they had no interest in doing anything about it. I tossed it in the waste basket, along with any metaphorical intent to use their products again.