Re: Recommendations for storing calculators Message #23 Posted by Phil K on 24 Mar 2009, 12:21 p.m., in response to message #7 by Chuck Sommer
Chuck, were all these batteries installed from a fresh pack and all at the same time? If not, even if all the batteries appear to be "in the normal range", if they are not nearly identical in voltage, the increased current through the on lowest voltage battery will cause it to heat up and if it does heat beyond the normal "gas leak" range, some of the Alkaline fluids can leak causing the problem you had.
As far as Lithium batteries, I have never seen one leak, nor heard of one leaking. I believe it is because they are essentially "dry cells", where the Lithium between the Anode and Cathode (Negative & Positive), is of a dry solid composition (actually a Lithium salt disolved in an organic solvent, but drier than an Alkaline battery). Also, if it did leak, I believe the PH of the solvent would not be Alkaline and so would not cause corrosion, but I could be wrong.
See below;
"The latest non-rechargeable lithium batteries utilize an even newer chemistry, that delivers dramatically higher energy capacity than even the very best of alkaline batteries. The operating lives (run times) of lithium batteries will often be two to six times that of the same sizes of alkaline batteries, depending upon the drain rate and usage cycling of the application. And the disposable lithium batteries provide amazing typical initial
shelf lives of ten years (and up to fifteen years for certain types), depending on quality.
Lithium batteries also weigh less and tolerate temperature extremes better than most other types, but they usually cost much more, and can become hazardous if damaged. Because of their extraordinary storage lifespans, and because most have a built-in vent to relieve any buildup of gasses, leakages of disposable lithium batteries are relatively rare, unless they are mishandled or improperly installed. So the remainder of this article will address the lower cost carbon and alkaline battery types, which will leak very readily.
When carbon or alkaline batteries have become discharged, the chemistry of the cells will degrade and some hydrogen gas will be generated. This out-gassing will result in increasing pressure within the battery. Eventually, the excess pressure will either rupture the insulating seals at the end of the battery, or bulge and rupture the outer metal canister, or both. When this happens, an acidic (for carbon cells) or caustic (for alkaline cells) electrolyte gel will ooze from the battery. In addition, as the battery ages, its zinc (for carbon cells) or steel (for alkaline cells) outer canister may gradually corrode or rust, and this can further contribute to leakage failure. Extremely high temperatures,
such as those in the vehicle glove box during the summer, can also cause batteries to rupture and leak, even when they are relatively new.
The leaking electrolyte can corrode the metal housing and battery contacts of a simple flashlight, and it can damage or destroy the delicate circuitry of an expensive electronic flashlight. Furthermore, swelling of the battery canisters can render one or more of the batteries hopelessly jammed within the flashlight body. One leaking battery can cause a chain failure, when its leaking goo corrodes the adjacent ones so that they then leak.
A five dollar set of dead batteries can and will destroy a five hundred dollar instrument if you let them. Countless numbers of otherwise perfectly fine flashlights are discarded every year due to battery leaks. Only you can prevent the tragedy of death by leakage.
The most important thing to remember is this: dead batteries will eventually leak. And all batteries will gradually self-discharge (even if they are not operating the device they are installed in, and even when they not installed at all but just sitting on a shelf or in a drawer, they will slowly lose energy capacity over the passing of time). So, no matter how good the brand name, your batteries will eventually go dead even if you don't use them, and when they go dead they will eventually leak. These simple facts lead to just three easy rules, which must be followed without exception to protect your investment in flashlights and other battery-operated equipment.
Always remove dead batteries immediately - All dead batteries are subject to very rapid leakage. When the batteries can no longer
effectively power the device, remove them at once and take them to a recycling center. If the device has several batteries, always replace every one of them at the same time.
Remove batteries when equipment is stored - Whenever a given device will not be used for any extended period of time (one month or more), remove and properly store its batteries. In extreme conditions, such as the car glove box in the summer in hotter climates, install the batteries only when needed.
Properly store and dispose of your batteries - Store uninstalled batteries in resealable plastic bags or battery carrier boxes, so that if they leak they will not damage nearby items. Check them every month or so for any swelling or leakage. Do not throw away weak or aging batteries, and do not just toss them into a drawer, but instead take them to a nearby battery store or recycling center
for proper disposal. Note that some states and municipalities now mandate recycling for all consumer battery types. Please help to reduce the environmental impact of the billions of batteries that expire each year, recycle them as if your future depends on it.
So what do you do if some batteries have already leaked and ruined your flashlight or other device? Some technicians will tell you that you can wet a toothbrush or a cotton swab with a solution of baking soda, and scrub away the acidic goo and crust from a
leakage caused by carbon / zinc batteries. Or similarly, apply a solution of household vinegar to scrub away the residues from a leakage caused by alkaline batteries.
This may actually work in some instances, but the cleaning solution could damage the delicate electronics in sophisticated flashlights or items such as radios and tape players. And while you may be able to open both ends on some flashlights to push out swollen batteries, some flashlights can only be opened from one end such that you cannot dislodge batteries that have become jammed due to swelling."
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