Learning from that G10 usage of internal battery that finally would come to the end of its lifetime, if it were me, I'd make an analogy of GLX-D14/16 usage of proprietary battery. Despite the GLX-D16 battery are user removable and seems no one has complained about its lifetime, still I would either choose another wireless system with more commonly found and cheaper to replace (which could also be rechargeable) AA batteries, or if I've already owned the GLX-D system, I'd buy few spares of that proprietary battery, while they are still available in the market, so that I could use the wireless system in long years to come.