Frequently Asked Questions

The battery is internal and not user replaceable. The battery life should be 2 to 3 times longer than the CoxBox 08 external battery. If the battery needs to be replaced, it would be sent back to NK for service.

If your display begins to dim, it is time to replace the batteries. REMEMBER all unsaved data will be lost when the batteries are changed.

The short answer is no. As long as you charge the unit until it is full, the battery will rebalance itself. For a more detailed answer, you can check out this graphical explanation

Do I need to rebalance the battery in the CoxBox Core/GPS?   (Size: 200.5 KB)

A graphical explanation on why charging until full will ensure the battery is balanced every time with the new CoxBox.

Please see our guide:

SpeedCoach/StrokeCoach Troubleshooting Documents

Troubleshooting Power Issues with SpeedCoach Red/Gold or Strokecoach   (Size: 570.1 KB)

This is a quick guide on what to look for if you changed batteries and the power no longer comes on with your SpeedCoach Red or Gold or Strokecoach.

You should get 2 to 3 times the battery life of the previous CoxBox 08. With a fully charged battery, you should expect 10+ hours of use.

We discovered an issue with certain SpeedCoach units where the fuel gauge would greatly overestimate the amount of battery life left. The symptoms are that the SpeedCoach shows full bars for a very long time before finally going to 4 bars. After a little while on 4 bars, the unit would shut off. We have developed a fix for this issue with firmware version 2.21. If you are seeing this issue, please update your SpeedCoach firmware to 2.21 and the unit should record battery life properly after that. If you have the latest firmware, please leave it on charge overnight to have it reset the fuel gauge.

Replace your battery (CR2032 Lithium watch battery), following the instructions on page 10. In rare cases, an electrostatic discharge (static electricity “shock”) may cause your display’s unit to go blank. In dry weather, a charge can build up while the unit is being carried in the storage pouch or a pocket and be discharged when the unit is touched or placed on the mounting bracket. If this happens, you can perform a complete reset of your unit as follows:

Open the battery door and remove the battery. Leave the battery out for at least 10 seconds while pressing and holding the button. Release the button and reinstall the battery. The unit should turn on and function normally when you push the button.

If this procedure does not solve the problem, and your unit is more than 2 years old, try replacing the battery.

The UN number to use for our SpeedCoach Lithium battery is UN38.3

Typical battery life in the Oarlock is 10-25hrs, depending on the battery and ambient temperature. We recommend high quality Lithium disposables or Low Self Discharge rechargeable NiMH batteries for more economical use. We do NOT recommend use of alkaline batteries because they are prone to leaking, particularly in a humid environment, and A LEAKING BATTERY WILL DESTROY THE OARLOCK ELECTRONICS AND IS NOT COVERED UNDER WARRANTY! Here are some batteries we tested, along with the duration they ran under typical use at 75°F:

If the battery has become very flat (low), it may take a little longer for the unit to show that it is charging. First please make sure the unit has “clicked” into place on the charger so that the silver contacts are aligned together. Then make sure you give the unit at least 30 minutes for the “charging” to appear on the screen. Typically after 30 minutes you should see a change from a blank screen to “charging”. If the unit is still not responding after more than 30 minutes on a charge, please contact NK for assistance.

Check the battery voltage and/or replace the existing battery.

The CR2032 is a common battery available at most local stores. A CR2032 has an average expected battery life of 400 hours.