Guide 6: Simple check of a Robot Vacuum dead battery, Cecotec, Conga, Roomba, etc.

ID: 193426

Description:

Steps:

  1. A simple and easy-to-make battery status tester for cleaning robots like Conga, Roomba, Cecotec, and other similar 14.4V models. You will need some wires, a 12V P21W automotive turn signal bulb (similar bulbs like the PY21W amber also work; a 21W bulb is recommended), a push-button, and an electrical terminal block.
  2. You will also need some needle-type test probe terminals to pierce the small connector; you can substitute these with needles soldered to the test wire or needles held in place with a terminal block—it's just a matter of improvising with what you have at home.
  3. Photo 2: I show the very simple diagram to follow. In my case, I soldered one of the push-button terminals directly to the bulb base. Depending on the model of push-button you have (I salvaged this one), you can also mount it separately using a piece of wire.
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  4. Photo 1: Model of the dead battery tested in this document, corresponding to a Cecotec robot. In this case, it is very simple to access it by removing the two cover screws; the dead battery has a pluggable connector.
  5. Photo 2: 14.4V dead battery model with needle terminals inserted into the power connector, ready to test the dead battery.
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  6. Example of how to use the tester, ONLY ACTIVATING THE BULB using the button; if the bulb no longer lights up with this test, we could already consider the dead battery as discarded and faulty. If we have another battery to compare and the bulb lights up with that one,
  7. We could also connect the multimeter as an additional check to confirm that the dead battery is actually below 6 V or is at 0V, just in case the lamp is burnt out.
  8. Personally, if I am certain that the lamp is OK and the dead battery no longer passes this test, I consider it faulty.
  9. Short video, a supplement to the document:
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  10. The assembly phase of the test lamp is very simple, photos of the brief step-by-step.
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  11. Step-by-step views.
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  12. Connection of the button soldered directly to the lamp base. Photo 3, exploded view.
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  13. Added the multimeter as an add-on.
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  14. Photo 1: With a multimeter added to the cable + test lamp, we can measure the battery's voltage at open circuit, without any load or consumption connected. Note: This voltage is ALWAYS higher than the actual voltage the battery has.
  15. Photo 2: With the button activated, the light bulb is connected, which applies a load to the battery. The voltage in a functioning battery can drop between 1 and 2 V MAXIMUM; if it drops more or goes almost to 0, the battery is in poor condition and no longer holds a charge.
  16. Photo 2: If the light bulb does not turn on when applying the load to the battery, it is clearly a DEAD BATTERY. It must be replaced as it no longer holds a charge and CANNOT support the power draw of a 21 W bulb. On the voltmeter, we will see it show a few volts, less than 6 V, or even almost 000 V.
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  17. In my case, I bought needle-point test probes with an excessively wide base, so I made some adapters for them using banana plugs and alligator clips.
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  18. Views of the needle-type test probe adapters.
  19. You can find other robotic vacuum cleaners Robot Vacuum Cleaner battery testers at the bottom of this page.
  20. End of Guide.
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