The good thing about lithiums is that that they require no maintenance and can be fully depleted. You cannot fully drain a NiHM cell. Okay, you can, but with seriously decreased capacity/lifespan.

The Low self discharge NiMh AA Cells such as Eneloop or Panasonic Infinium are probably the way to go.



For AA NiMh cells the iSun BattPak is a useful addition. It works as a Battery Charger designed to work directly with portable Solar PV panels such as a Silva II portable 4W panel shown above (it also works well with a 25W folding solar PV panel). Once charged the BattPak will then function as a portable power pack via its own Cigarette car type 12V connection. The Battpak can also be charged using a regular AC-DC supply or suitable DC supply such as SLA or lead acid car battery. There are bound to lots of working lead acid car batteries in non working vehicles available after an earthquake. A small 12V DC-DC switching regulator could also prove to be very useful.

Primary Lithium such as Energiser and Ultralife are pretty specialist cells, they are pretty much unsurpassed (at the moment) for portability i.e. low weight, excellent cold temperature operation, long life and storage lifetime. They are expensive but $20-30 worth of Energisers AAs could prove to be invaluable in the next 10-20 years. Keep some alkalines around as well, just so you are not tempted to open the packets Enerliser Lithiums if the TV remote needs feeding.

I sure appreciate all sharing their knowledge. For sure I'm going to buy a car charger and probably a battery meter as well. For most of my battery use the eneloops seem to be a better deal. Lithiums do have the advantage for a device I want to have handy, but seldom use. Again, many thanks.

That's my real life experience with eneloop as well, but I haven't done much in therms of lithium testing. But the laws of physics can't be ignored: Lithiums are less affected by cold and hot temperatures than any other battery technology. The "others" (alkalines, ordinary nimh and eneloop) doesn't like to be stored in hot temperatures and will have reduced performance if you drain them in the cold.

Notice that performance in the cold is also a question of how much you're drawing from the battery. High drain applications will have significant reduced performance: Catastrophic bad with alkalines, quite bad with ordinary nimh and probably noticeable with eneloop. Low drain applications will be much less affected, although run time will be reduced.

For me, it is a question of the eneloop will work where I live and for what I do. So far, the answer is a resounding YES. Lithium is for long time storage (the "DO NOT OPEN" labelled package). Eneloop is what I use on a regular basis. Alkalines are for low drain devices (remotes etc) and toys, gradually shifting toys that are used towards eneloops as well. But I detest and hate one-time only use items...

As a side note: If more devices accepted rechargeable li-ion I would use them - but not for long time storage (they don't store too well fully charged). So far, only a few exotic flashlights will eat li-ion batteries in my house...

lithium ion has its own issues, for one thing less standard sizes (I know the cells are standard sized but the packs they build from them are not) and every lithium ion device needing its own sharger (I'd have a rats nest of chargers if I went lithium ion) and they loose more of their life per year, usually hitting 80% life after 2-3 years where I have NiMH that went 10 years before dropping below 80%.
I avoid Lithium ion for thse reasons.

Whilst lithium and eneloops have much to commend them, standard alkalines have the advantage of low cost.

IMHO the best way to store alkalines is in a "cooler" which of course does not really cool at all.
Articles placed in such a thermally insulated box will reach the same average temperature as the suroundings, but will be protected from extremes of temperature.

Reputable alkaline cells keep for 7 years from production, or about 5 or 6 years from purchase.
The risk of leakage is reduced by storing at an even temperature.

I keep cells in the suppliers packaging, and have had very few leak.

Despite the simplicity of only one cell size, it might be worth stocking D cells in addition to AA.
D cells contain about 7 times more energy than AA for only about twice the price, and are therefore preferable for any longer term emergency such as the aftermath of a bad earthquake.

I keep two cubes of 30 standard alkaline AA in the basement, which I use as needed and replace when I get to one cube. The shelf life is five years if kept cool. The intended emergency use is a lantern, two-way radios, flashlights, FM/weather radio. I have never had a battery leak in storage, but I did have a leak in a little-used flashlight and a AAA powered remote once. Here is a link to some technical information: http://www.greenbatteries.com/batterymyths.html

I've had a couple alkalines leak in the original packaging, they were in the 30 packs from home depot so I've quit buying them and am buying the energizer now. It could be that they were dropper or somehting, hard to say but had leaks in more than one pack.

Alkaline batteries have the advantage of lower initial cost, but are ultimately more expensive than rechargeables. Lithium batteries, because of their higher energy density, are usually cheaper as well, depending upon how good a price you get for the alkalines (buy the Costco brand for the ultimate low price).

I would like to quote a recent Consumers Reports study (Dec 2009) on this topic, but I can't get my hands on it right now.

I still keep some alkaline batteries around and they are OK for something that will be used regularly with prompt battery replacement, like a GPS receiver, but I use them less and less.

When you factor in the cost of the items they damage through leakage, alkaline batteries are surprisingly pricey.

So far I've only had a couple kids toys have a leak, was from some of those rayovac packs. most of my good gear has bee using eneloops since 2006 or 2007 whenever they were first out in stores.