Have you ever experienced this with the CAB-2 remote:
After about 7 years, the rechargeable batteries in the remote started to discharge faster, so I decided it was time for new batteries. The old batteries that had lasted so long were Energizers, so I replaced them with Energizers. However, the new batteries discharged very quickly, including after they were recharged in the 990 base.
I decided to try another set of new batteries; this time, I got Tenergy Centuras. Before I installed them, I checked their voltage; it was 1.28. After I installed them, the CAB-2 initially displayed 3 bars for the charge level. After a very short time, however, the CAB-2 started displaying 2 bars for the charge level, and that reading has remained since, even after I recharge the batteries in the 990 base and their voltage is back up to 1.27.
Could there be something wrong with how the CAB-2 is reading the voltage of the batteries, or is something else going on?