Group Actions
Engagement
  • Author Author: shabaz
  • Date Created: Date Created
  • Views 2427 views
  • Likes 0 likes
  • Comments 17 comments
Related
Recommended

Leaking Alkaline Cells

shabaz

I just opened up a (semi) expensive bit of equipment and discovered the Duracells inside had leaked with the typical

white powder (potassium hydroxide) : (  and corroded contacts in the battery compartment as the result.

These ones were dated 'best before' March 2024, and had been inserted for less than a couple of months (and had just average use

during this time).

 

I was wondering what experiences others have had, and if they have successfully brought product liability charges against the manufacturer.

In the UK, a manufacturer can be held responsible for their faulty product, and any damage to property or to people (pure economic loss is not covered -

i.e. down time, loss of earnings, etc). However I expect in most cases the manufacturer just settles before a claim is raised in court.

 

I believe it is well known that Duracell batteries leak (something they don't mention in their bunny commercials) - so I always try to purchase Energizer or

other brands, but sometimes stores only have the Duracell option for alkaline cells : (

 

image

  • Alkaline cells will begin to leak if you discharge them more than about 0.6V to 0.7V.  When I have the budget in a design to do so, I add a nano-power comparator+reference and a MOSFET to shut off the battery at 0.65V [per cell].  Hopefully, this will prevent leaking cells in my designs that are now out in the field.  The MOSFET also doubles as a backwards-battery protection circuit [looks like a blocking diode if the battery is reversed, but if the battery is installed correctly and has enough voltage then the MOSFET is turned on so there is no diode drop in the forward direction].  Sorry I can't share the circuit-- as that is under NDA, but it is a very simple circuit and is easy to figure out on your own...

  • in reply to jw0752

    Nice pics.

     

    I can see how you would need to be careful ....

  • in reply to shabaz

    so low risk of overheating

    I was thinking of environmental heating being a contributor more than purely the load ...

     

    Mark

  • in reply to jw0752

    Thanks

    I've had a whole bunch of stuff to sort out before a 4 week trip in early August to meet some english and belgium minions..

     

    Mark

  • in reply to shabaz

    Hi Shabaz,

    I have performed a battery autopsy. The first recommendation is to make sure the battery is fairly dead. It would be difficult to separate the Anode from the Cathode without shorting the two together. The subject battery was dated 2011 and had leaked. It was marked as Made in USA and did not look suspicious with respect to being a knockoff. I am quite sure it is genuine Duracell. The case is the Cathode unlike older Zinc - Carbon type batteries I took apart as a kid. Here is the original picture.

     

    image

    I peeled back the label and separated the Anode cap from the Anode. It was spot welded in two places at 180 degrees. Below the cap I could see 3 small vent holes in the metal.

     

    image

    Battery with label removed.

    image

    The anode cover cap has been removed.

     

    image

    After using a diagonal cutter to peal the edge, this is where the anode and cathode get shorted together and where things will get hot if the battery isn't already dead, I removed the "Nail" that collects the negative charges. The "Nail" in this battery was 1.4mm in diameter and I measured 31.62 mm from the end of the Nail to the front of the Anode where I had removed the cover piece, shown in the foreground of the picture. To take it apart further looked messy and probably not very productive so I will stop at this point. There were no identifying internal marks that I could see that would help determine whether the battery was indeed genuine or not. Perhaps the dimensions of the Nail will be an indicator but then again they may have changed this with successive production runs and upgrades.

     

    Battery Coroner John - Signing Off