I am receiving a low battery state when I hook my data logger up to BoxCar® even though the voltage in the battery tests fine.

HOBO Pro data loggers manufactured prior to July 2000 had a design-related battery problem.

THE PROBLEM:

In certain situations, the internal resistance of the HOBO Pro battery increases to a point where the data logger may not operate correctly. A battery with high internal resistance has difficulty delivering adequate current to the data logger.

This leads to a false low battery indication from BoxCar. In rare instances, the internal resistance of the battery has led to missing or corrupt datafiles.

THE SOLUTION

Onset engineers devised a simple, effective solution called the HOBO Pro BatteryAssistant Module. The BatteryAssistant is a small circuit board that is inserted inside the HOBO Pro case. Installation does not require the return of your Pro logger to Onset, and it is as easy as replacing the battery.

The following serial numbers fall into this category:
Part #:

H08-030-08

Serial numbers less than 356453

H08-031-08

Serial numbers less than 333396

H08-032-08

Serial numbers less than 370243

If you have been experiencing problems with your HOBO Pro, or if you intend to use your HOBO Pro at temperatures above +30 °C, we recommend that you request a HOBO Pro BatteryAssistant (Part # Pro-Batt Assist). One BatteryAssistant is required for each HOBO Pro). Serial numbers greater than 433315 on all HOBO Pro models have a built-in fix. Serial numbers that fall in between the ones listed above and 433315 were shipped with a battery assistance board installed.

To order the HOBO Pro BatteryAssistant, contact us at one of the following numbers:
1-508-759-9500
1-800-564-4377

With the BatteryAssistant installed, your HOBO Pro will operate reliably within a temperature range of -20 °C to +50 °C. Within that operating range, the standard Onset warranty applies.

The HOBO Pro data loggers were redesigned to incorporate this fix into the schematic.