There is a trade off between operating networks that are able to keep operating in the face of disasters and keeping down costs. For example, a 24 hr battery will yield a more robust BTS than a 8 hour battery. But as the FCC initiated discussion revealed, 24 hr batteries impose additional costs on operators. Local rules in some cases do not allow enough space for 24 hr batteries. The issue is, no doubt, important.
Now that telecom networks have a bigger footprint than electric power networks, the question of power sources is assuming increasing importance. Quite a lot of work is being done in our region on reducing the power requirements of base stations and of substituting for expensive diesel generators. In Pakistan, using renewable sources at base stations are mandatory for those obtaining subsidies. The power is also made available for the recharging of handsets. But would it not be wonderful if handsets require no external power and no batteries?