Monday, June 20, 2011
Disappeared Technology #1: Leakproof dry cells
by Larry Geller
I’ve mentioned some technologies that never got to Hawaii, for example, permeable pavements that let the water filter right through into the ground. This technology, coupled with laws in some states and municipalities that make developers responsible for managing their own storm water, relieve the stress on ageing sewer systems and wastewater treatment plants.
But there are also technologies that have truly disappeared. And I don’t mean buggy whips and other things that have become anachronisms or lost their utility.
Today I’ll introduce the first in a series on Disappeared Technology. Our topic: leakproof batteries.
“Batteries” should properly called dry cells, but the term seems to be in disfavor. I have an idea why. Perhaps it is because staying “dry” is a goal seldom reached.
Disappeared Technology: Leakproof dry cells
Last month I took a battery-operated closet light out to change the three AA batteries, since it wasn’t lighting up any longer. When I opened the battery compartment, I learned why these things are not called “dry” cells any more. The inside was sloshing in leaked electrolyte.
For the record, the batteries were Kirkland, and were well within their expiration date.
So I cleaned it out with a cotton swab and baking powder. The idea is to get every bit of it out or the contacts and electrical parts can corrode later on.
As I cleaned, which is a huge waste of time (but thank goodness I got to it early), I was reminded that when we lived in Japan, the Sony AA batteries we used never, never leaked. In fact, they had a little warranty on each one saying that if the battery leaked, Sony would replace the item with the same one, or if it should not be available, with one of equal value, plus new batteries.
They can’t. Their products leak. Sometimes the contacts corrode and have to be cleaned.
The Duracell batteries pictured at left were never used, and had not expired. Well, they obviously did expire, but I mean the expiration date had not been reached. They sat in a cool, dry place, along with their package-mates, but they clearly had died.
I once saw a pair of Eveready D cells still in their blister pack hanging on a hook in Safeway, both covered with thick white fuzz.
In Japan, I used Sony AA and AAA batteries in all my flashlights and radios. I had a tiny Sony shortwave radio that we took with us on our trips around Asia. It was exceptionally well designed and very expensive. Of course, it had Sony batteries inside. Would I have dared put something leak-prone into a radio costing several hundred dollars? No way.
Whether the Sonys just sat on the shelf or whether they were run down from use, none ever leaked. In 16 years, none leaked. So there is technology that keeps a battery from leaking.
And that technology either never made it to these shores, or it has disappeared.
Duracell, Energizer, and RayOVac all have warranties covering damage from leakage. I think after 2009 or so the cells have gotten better. The easy anti leak technology until the mid 1990s was mercury. But, the best bet for expensive equipment is Eneloop or other LSD NiMH rechargeables, or lithium if appropriate.
In days gone by batteries (here in Australia at least) had "leakproof" printed on them. And they did not leak. The occasional faulty one maybe; but everything has a fault tolerance. Now that statement has disappeared. Duracell are by far the worst. As stated in the article, they leak whilst still in the pack. NEVER buy a bulk pack; you'll throw half away in the end. I thought at first maybe it's because they are alkaline and the old ones weren't. But then the batteries in our computers that keep the clock etc going are all alkaline and I have never heard of one leaking. Ever. So is it just that for use on mass produced cheap goods they use low production quality product. For batteries to be used on high cost computers (and higher repercussions) they have a higher quality control.
The batteries to back up the clock or BIOS on computers are almost always lithium primary cells. Usually LiMnO2 coin cells like CR2032 now, but 15-20 years ago larger Lithium-Thionyl chloride (Li-SOCl2) chemistry cells were popular. Some were AA size, or AA diameter half-length. All the brands leak, if anything Panasonic might have an edge, but AFAIK it's a toss up between the big three. Main reason is trying to get more capacity in the same size cell.