It is always good to use rechargeable batteries but i think it is also wise to keep at least some disposable batteries, in enough number as to be able to run what you need them for (radio, flashlight, blood pressure monitor, etc). My reason for this is although rechargeables are good they are also not 100% reliable. Kahit Li-ion pa they will fail or you will forget to charge them. Having conventional batteries on hand makes for a good back up plan.

Duracell now makes batteries that have more than 10 years shelf life.