Electronics > Projects, Designs, and Technical Stuff
New Alkaline Battery Leakage Testing
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EEVblog:
So I'm going to rerun this experiment as clearly my 47ohm load last time didn't do the trick.
From what I've been able to gather, the key seems to be almost complete discharge (it will build up the most pressure near the end of it's life) and then either a very light self discharge load (I think 10uA out to do it, very typical product "standby" load), or no load at all?
Of course I can do multiple combinations.
No series cells this time, just individual ones.
And of course there would be debate over what 90% and 100% discharge is.
Obviously can't put the light load on fresh batteries or it'll take years, so test acceleration is the key.
Suggestions and comments invited!
mzzj:
Only anecdotal evidence but these are the worst situations I have come up with:
1. High current pulsed discharge (couple of 10 second 10A pulses)
2. discharge to 0v and below, ie reverse polarity for weakest cell in equipment with several cells in series.  Maybe like 10% mAh capacity with reverse polarity. 
kallek:
This is interesting experiment. My suggestion is to drain some of the cells to about 1V per cell at 100mA current, and leave with light load. And drain some cells to 0.5V and leave with no load.
graybeard:
Put the batteries in a valuable piece of equipment since those are the ones that always seem to leak. ;)

Temperature cycle the batteries while partially drained and with a very light load.  Most real devices see temperature cycles somtimes extreme.

For example device left in a car could see temperature as high as 140ºF (60ºC) when left in a closed car in the sun summer, and below freezing -10ºF (-23ºC) in the winter.  Uninsulated garages where many items are left also see temperature extremes.  Even houses which have the heating and colling reduced when occupants are away can have large temperature excursions.

Perhaps it is a combination of being discharged and or slowly discharging plus the expansion and contraction of temperature variations that causes the leaks.
graybeard:
Besides the temperature cycling you could run the test as several elevated temperatures.  Most failure mechanisms are Arrhenius and have an associated activation energy. 

By running the test at several elevated temperatures you could both speed up the failures and measure the activation energy of failure mechanism. 

Over the years I have designed hardware for many reliability tests and most failure mechanisms are both temperature and current driven.   Typically failures rates are exponentially dependent on Temperature (0.5 to 2 EV being a typical activation energy) and dependent on current density raised to a fixed exponent (typically 1 to4). 

Sometime humidity plays a role, but controlled humidity experiments are much more complicated to design.  However since battery leakage does seem related to corrosion perhaps moisture is a factor.
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