Battery "shelf life" in harsh conditions

I keep our bug-out bags in the garage (not worthy of indoor storage as the idea is NOT to need them). Garage can see a pretty wide range of temperature extremes (though I've not actually measured

*at* the spot where the bags are stored) from teens to well over 120-140F.

I periodically replace the batteries stored in them as a safeguard against them "being flat" when needed.

I'd like to store NiCd's as they could potentially be recharged if/when needed whereas alkalines are disposable -- not a good idea if there isn't a convenient source of FRESH batteries available! (there are a couple of charging mechanisms that I have available in that deployment case).

[Note I don't expect the NiCd's to hold a charge while in storage; but, would like them to be able to TAKE a charge thereafter!]

So, what's the downside re: NiCd's exposed to inhospitable conditions? Am I better off stockpiling several dozen alkalines? And, replacing them (while thusly stored) how often? (note temperature cycling)

Reply to
Don Y
Loading thread data ...

You don't want to let a NiCd go flat in storage -- it's an unhappy little electrochemical cell after that.

What you want to do is to keep it fully charged, and charge it up just a little bit every day or so, to regain ground lost to recombination without over charging it. Like those plug-in emergency flash lights.

Then replace every year or two...

--
www.wescottdesign.com
Reply to
Tim Wescott

Divide your bug-out bags into two pieces. Perishable and nonperishable. Put the batteries in the former inside. Anything worthy of residence in the bug-out bag is worthy of proper storage and periodic rotation. You're either prepped or you ain't.

I think I'd prefer LSD NiMH and a solar charger over NiCd.

I bought 7 of those AA zoom flashlights of ebay when they were cheap. Put Enloops in 'em. Put 'em in a line on the shelf. When one goes flat replace it with one off the shelf, charge the flat one and put it at the end of the line on the shelf. You always have known good flashlights.

I once gave a lot of thought to bugging out. Concluded that there are two types.

1)Evacuate until the hurricane passes. Tank of gas, bottle of water, can of beans and a flashlight.

2) You're screwed. The radiation ain't gonna subside. No matter how much stuff you take, it ain't enough. And if you do take sustenance, ammo might be your best chance of survival. Nice guys finish last.

I didn't buy that bucket of dried rations.

Reply to
mike

There are types of nickel?metal hydride cells that are perfect for long storage. The brand I use is Enloop. They only lose 15% of their charge the first year. Looking at Wikipedia, it seems this is not a constant, over the years they have improved and branched out to several variations of cost and capacity as well as the other factors. But all of them should provide long shelf life as long as they are charged every two or three years. A version sold at Costco now has the claim on the package of holding 70% capacity for up to 10 years! They don't seem to show the capacity though.

--

Rick C
Reply to
rickman

Two countries separated by a common language! Wot's a bug-out bag?

--
Regards, 
Martin Brown
Reply to
Martin Brown

When the shit hits the fan, what FEW items do you want to grab IN A HURRY, without having to think about your choice AT THAT TIME? E.g., a means of starting a fire (for warmth, cooking), a means of wiping one's ass, financial records (thumb drive), medications, first aid kit, etc.

Reply to
Don Y

OK. I understand having lived in an earthquake country - we have fresh water tank and enough canned food for a few days. But apart from a forest fire or flood I can't think of any situations (*) where you would need to make a split second fight or flight decision. We are not exposed to either risk where I live now. Most times you are better off staying put where you have neighbours, tools and local knowledge.

(*) Except chemical, biological or nuclear but even then staying indoors at home is still probably the best bet.

The extent of problems we get in the UK are mostly winter storms, floods and powercuts (very few tornadoes). Where I live in the wilds is a bit prone to power cuts but we have never been off grid for more than a couple of days. Some low lying places get hit a lot worse.

Wood burning stove, plenty of candles and a generating set means we are pretty much self sufficient. Being snowed in or cut off by fallen trees is also a bit of a hazard but again we have enough local resources to sort most things out sometimes before the authorities can respond. Been snowed in for nearly a week in the past but with global warming we barely saw any snow at all in the past few years.

By comparison a lot of modern build homes are reliant on mains water, gas and electricity and JIT supermarket delivery chains. If any one fails they have no redundancy or resilience.

We have solid fuel and a big oil tank and if needed a genset.

Military style stay fresh rations don't need to be heated but clean safe drinking water is essential. Inexperienced people invariably underestimate the amount of drinking water they need in a wilderness trek. You die of thirst long before you die of starvation.

--
Regards, 
Martin Brown
Reply to
Martin Brown

In general, primary cells such as alkalines have lower self-discharge rates than rechargeable cells. A "brick" of alkalines, swapped out every couple of years, is an inexpensive and pretty reliable solution.

You might want to consider keeping your go-kits in the most temperature-stable part of the garage. Sitting 'em on a concrete floor, away from the exterior walls, for example... the ground would serve as somewhat of a temperature-stabilizer and might reduce the exposure to heat (which is probably the biggest age-accelerator for any batteries).

Other alternatives:

- "Low self-discharge" NiMH batteries ("Eneloop" is one brand name). The best of these have a very respectable self-discharge rate - I've gotten about 80% capacity after a year or so of on-the-shelf storage under moderate conditions. Once a year (or every six months if you want to be extra-cautious) run them through a "discharge, recharge, discharge, recharge" conditioning cycle (the better charges can do this automatically) to maintain their storage capacity.

- Lithium "primary" AA batteries (e.g. Energizer "Ultimate"). These are rated as having a shelf life of up to 10 years, and have quite a bit more capacity than alkalines (especially under high-discharge load conditions). One caveat is that their starting voltage is higher (sometimes as high as 1.8 volts) and some devices might object to the increased voltage. They aren't cheap, but their high capacity and long shelf life can make them an attractive option for many uses. Buy 'em in boxes on-line rather than buying retail 4-cell blister packs, and the price-per-use is reasonable.

There's no reason for you to limit yourself to a single solution... stick in a couple of sets of lithium AAs, and a couple of sets of NiMH and a charger (ideally one which can run either on a wall wart or a car battery). That'll leave you with some "ready to go" power, and a set of rechargeables for use if you have a long incident to deal with.

Reply to
Dave Platt

That's what? a 3-day pack? how many batteries do you expect to need in those 3 days? are you planning to pack a crank-operated charger and fuel that with C-rations? or a solar hat and hope the emergency brings clear skies?

--
This email has not been checked by half-arsed antivirus software
Reply to
Jasen Betts

You could make a 'floaty thingie,' & keep all your NiMH cells topped-off.

formatting link

(FWIW, I measured the self-discharge of a AA-NimH ages ago at ~2mA. YMMV)

Cheers, James Arthur

Cheers, James Arthur

Reply to
dagmargoodboat

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.