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Weather Station Battery Test

By October 10, 2017September 7th, 2023Blog

Design Principle

Most Dyacon weather stations ship with a battery and solar panel. The 12 VDC 7 Amp-hour battery sustains the weather station over night and can even run the weather station for about one week without recharging.

All Dyacon weather station controllers have an embedded solar charge controller. The internal battery recharges each day using power from the solar panel.

The daily charge-discharge cycle gradually reduces the battery capacity. Batteries that operate in cold temperature environments or are deeply discharged will suffer more capacity loss than those that operate in room temperature conditions.

Weather station batteries take a lot of abuse and should be replaced routinely for reliable operation.

Battery Testing

So, how do you know if your battery needs to be replaced?

There are several indicators:


Batteries that are three years old are probably past due and may not have sufficient capacity to ride through a winter storm with snow cover or severe cold conditions.

Annual replacement in cold, northern climates should be the rule.

Stress Test

You can unplug the solar panel and see how long the battery lasts. This should only be done in non-critical applications. If the weather station ceases to operate within two days, the battery capacity has been significantly reduced from its new condition.

End-of-night Voltage

By looking at the battery voltage in the log file or using the SMS text message “Debug” before the sun comes up in the morning, you can determine the battery voltage after overnight discharge. A good battery will have a voltage above 12 VDC.

Service Alert

Beginning with firmware v132, the weather station will notify the Service Technician Cell (SC) phone number with a low battery text message. At the point that this message is sent, the battery is in very poor condition. The message is an indication that the weather station is shutting down some functions in order to preserve data. The controller will return to normal operation once the battery is 12.3 VDC or greater.

If you would like to have this feature, please contact Dyacon for instructions on upgrading your firmware. The update is free.

Battery Replacement

We selected a very common battery form factor for Dyacon weather stations. You are likely to find a replacement at your local battery store, but these are typically intended for uninterruptible power supplies, backup lighting, or other indoor standby applications.

We originally used Enersys Genesis batteries, which have a good reputation. CSB, PowerSonic, and Yuasa are common brands and aren’t a bad choice if you have ready access to them.

The challenge for field instruments is recovering from deep discharge conditions, which can occur during extended winter storms. After several incidents of battery failure, we switched to Panasonic batteries in 2015 and have found them to be exceptional performers. Unlike other brands that contract with different factories for their battery production, Panasonic operates their own factories and has a reputation for consistent, best-in-class performance.

Please give us a call and we will help you evaluate your weather station and get a battery shipped to you right away if it is needed.


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