I don’t know about you, but I’ve always found that the rechargeable batteries that replace disposable batteries somewhat lacking. The nickel-cadmiums (NiCd) suffered from the memory effect and the nickel metal hydrides (NiMH) eliminated that, but still lost charge when not in use. I’m currently using the Hybrio / Eneloop batteries which solve both of the above, but they still lack power, largely because they’re only 1.2V instead of the juicy 1.5V of disposable batteries. I’ve even a few gadgets that simply won’t work with the lower voltage.
So, if you are like me and have children who get through batteries faster than a knife through butter, you might be interested in new nickel-zinc (NiZn) batteries that are coming onto the market now from a company called PowerGenix. The best bit is the voltage on these is 1.6V and by all accounts, they last well. Once the technology gets picked up by the mainstream battery companies, it will probably improve further.
They’re available now in the US but they don’t seem to have made it over to the UK yet. As soon as they do, I’ll get a few to test out and compare against the Hybrios.
Also on the battery front, this article from the BBC highlights the issues around lithium production and why there is likely to be a shortage in the not-too-distant future. Looks like good news for Bolivia but bad news for the Salar de Uyuni.
P.S. I checked the technology out on Wikipedia and I was surprised to see that NiZn batteries were used on the Dublin-Bray train in the 1930s and 40s. Had problems with limited discharge cycles, mind you.