Techies - Mop It Up

Scenario:  My close friend's Swiffer WetJet "broke" recently.  For those who haven't used one before, it's essentially a mop with a nozzle mounted on it so that when you push a button, cleaning fluid is sprayed on to the surface just in front of the mop.

It's been a really long time since I've updated this.  The past year or so has been extremely busy and most times, all I want to do when I get home is sleep.  But school is done now, so YAY!


At first we thought it was out of fluid (which it was) but changing a new container did work.  Then we thought it was out of batteries, so we changed the batteries.  Nothing.  The main symptom was that the button was unresponsive.

At this point, I realized that if it was functioning, we'd be hearing the light buzzing from the electric motor.  From this, I deduced that it was an electronic failure of some kind.  I asked her if I could take it home and I began a more thorough operation of the patient.

I wanted to be as thorough as possible and not be foiled by some simple issue... so I tested to make sure each AA battery was indeed producing 1.5VDC using a mulitmeter.  Check!

Then I decided that there were three components in the circuit I needed to test.

The first was the button that activates the spray.  Using a multimeter, I set it to measure resistance and clicked the button.  I successfully saw changes in resistance from an open circuit to a numeric value.  The button was not the issue.

 The next component was the electric pump that sprayed the cleaning fluid.  However, this was more difficult to get access to.  By inspection, it looked like it required removal of the shaft and the cleaning fluid's cartridge receiver, so I decided it should be a last resort.  You might actually just call it being lazy...

The third component to check was the battery terminals.  Leakage from the battery had caused the terminals to be coated by the products of the chemical reaction.






If you remember from high school, batteries are made up of two chemical reactions, each called a half-cell; one side produces electrons, and the other side takes up electrons.  The movement of the electrons between the two cells can be harnessed as electricity and used to power whatever we have put our batteries in.  As the reactions progress and the reactants get used up, one of the products is actually a gas.  This gas tends to expand and, over time, the gas starts to break the battery casing.  The products then start to leak and this is when you get the rusty "moss".  This rust is non-conductive, which means that electricity from the battery can not go through it.  If the power terminals are coated by this rust, then electricity from the battery is not getting to your motor.

Simply, the fix for this issue was to clean off the rust.  I carefully scraped off the rust and buffed the terminals a little bit.  The rust itself is still toxic, so I had to be careful not to get it in my eyes and wash my hands after.  I put both the rust powder and the dead batteries in a little bag and gave it to my local battery disposal unit.  After I returned the mop to my friend, we stuck in a new cartridge and fired it up.  The house was clean just in time for Chinese New Year!