Sensor Reports Hardware Failure (Short)

Monnit sensors will report the error Improper Battery Placement if the sensor's battery is not inserted correctly or if a hardware issue creates a short in the sensor's circuitry. Please consider a few things and check if you see this error.

Possible Causes of the Improper Battery Placement Error

The conditions listed below can result in this error:

1. The battery is not fully inserted, leading to a low voltage detection.
2. A hardware issue is causing a low voltage detection.
3. The sensor has been exposed to liquid ingress.
4. The sensor has been exposed to high heat.
5. The battery is not performing as expected.

Check for Damage or Liquid Ingress

You'll first need to do a quick visual survey of the sensor for damage or signs of liquid ingress because this error is a common cause. It is worth noting that you may need a replacement if you have a sensor exposed to liquid. Liquid ingress (and, in some cases, damage) may not be repairable.

Battery Not Fully Inserted

Especially with coin-cell sensors, it can be common to see a few consecutive Improper Battery Placement readings when inserting/reseating a battery. While this can be normal behavior, it is not common to continue to see this error when a battery has been fully inserted.

Coin-cell Sensors

This error generally occurs with the coin-cell form factor. If a coin-cell battery is not completely inserted, the battery cannot make complete contact with the battery cage, resulting in a low voltage supply. If you see this with a coin-cell sensor, remove the battery for 60 seconds and insert it securely. If the error persists, reset the sensor to the default configurations in iMonnit using the Default button in the sensor Settings, and replace the sensor's battery with a new one. If the error persists at that point, you may be looking at a hardware issue.

AA Sensors (including MoWi)

An AA battery-powered sensor doesn't generally experience issues with the battery not being inserted fully due to the type of battery cage used. However, you still want to open the enclosure and examine and reseat the batteries. If the error continues, please reset the sensor in iMonnit to the default configurations using the Default button in the sensor Settings and replace the battery with a new one. If the error persists at that point, you may be looking at a hardware issue.

Industrial Sensors

The industrial form factor also sometimes experiences issues with the battery not being inserted fully. Since these sensors are sealed, Monnit does not recommend opening the industrial sensor enclosures. If you have this issue with an industrial sensor, do not open it, as it may void the sensor's warranty. Instead, please look over the enclosure for signs of damage, liquid ingress, or corrosion.

You may want to look closely at the enclosure for hairline fractures if the sensor is mounted and the screws have been screwed tightly enough to damage the enclosure. Look for signs of corrosion and rust. If no damage or signs of liquid are detected, and the error persists, reset the sensor in iMonnit to the default configurations using the Default button in the sensor Settings, and replace the battery in the sensor with a new one. If the error persists, you may be looking at a hardware issue or liquid ingress inside the enclosure.

Liquid Ingress

Liquid ingress is likely the most common cause of a persistent Improper Battery Placement error. If the error persists after resetting the sensor and inserting new batteries, this is the likely cause of the error. It is worth noting that sensors exposed to liquid ingress are often not repairable.

A typical scenario: 

Sensors are often exposed to condensation when installed to operate inside refrigeration or freezer units. This occurs when the cold, dry air in the refrigerator or freezer combines with warmer, humid air from the outside. When this happens, condensation forms and can often damage sensor components exposed to the humidity. For this reason (among other reasons), operating coin-cell sensors inside refrigeration or freezer units is not recommended. AA sensor enclosures are also not protected against moisture, so that they can be exposed to condensation.

Liquid Ingress in Coin-Cell Sensors:

If the sensor is used in an environment without stable temperature and humidity, liquid ingress in coin-cell sensors is expected. Coin-cell sensors are designed to operate in normal conditions in which they are not exposed to drastic fluctuations in temperature and humidity. While humidity doesn't damage the sensor, condensation issues often occur when temperature fluctuation or a meeting of humid air and dry air occurs. As a result, coin-cell sensors are not designed to operate inside fridges or freezers. Optimal operation with coin-cell batteries is between 50°F – 80°F (20°C – 26°C) in 40–60% humidity.

Liquid Ingress in AA Sensors (including MoWi):

While AA sensors have an enclosure that protects the sensor hardware from condensation more than coin-cell sensors, AA enclosures are not rated to protect against liquid ingress. Therefore, these sensors tend to perform more reliably in variable humidity (and temperature) as a result of the AA batteries vs. coin-cell batteries. However, they are still at risk of exposure to condensation and temperature fluctuation. Therefore, while you can expect better reliability when using AA sensors in environments exposed to condensation or liquid, they are still at slight risk of experiencing issues.

Liquid Ingress in Industrial Sensors:

Industrial sensors are IP and NEMA-rated to resist liquid ingress and dust. Therefore, liquid ingress is not generally a concern when operating industrial sensors in refrigeration units, freezers, or other environments exposed to the elements. Therefore, if you have an industrial sensor that shows Improper Battery Placement, it is generally a result of a compromised enclosure. A 1-year warranty covers industrial sensors, and if they experience a hardware issue or liquid ingress, a repair is usually covered under warranty (unless it is determined that the sensor was exposed to conditions outside of the NEMA and IP rating and specifications).

Exposure to Heat

Exposure to heat outside specifications can also cause this issue or error. The temperature specifications for each form factor are listed below.

Coin cell: Operating temperature range (board circuitry and coin cell) -7°C to 60°C (20°F to 140°F)

Optimal battery temperature range (coin cell) 10°C to 50°C (50°F to 122°F)

AA: Operating temperature range (board circuitry and batteries) -18°C to 55°C (0°F to 130°F) using alkaline

-40°C to 85°C (-40°F to 185°F) using lithium

Optimal battery temperature range (AA) 10°C to 50°C (50°F to 122°F)

MoWi: Using Alkaline Batteries: -18°C to 55°C (0°F to 130°F)

Using Lithium Batteries: -40°C to 85°C (-40°F to 185°F)

Industrial: Operating temperature range (board circuitry and battery) -40°C to 85°C (-40°F to 185°F)

Battery Performance

The Improper Battery Placement error can occasionally be a result of battery performance. If the issue is caused by an issue with a battery, replacing it with a known good battery is often a quick resolution.

Conclusion

If you have a sensor that reports Improper Battery Placement, resetting the sensor and replacing the battery (where applicable) doesn't fix the issue, you can contact Monnit Support.