4. Head sensor
Questions, answers and instructions regarding head sensor
Questions, answers and instructions regarding head sensor
How to turn the sensor on and off?
1. Switch the sensor on by pressing the on/off- button once slowly and firmly. Red led-light next to the button starts blinking in slow frequency to indicate the sensor is on.
If the led light does not come on at all, the battery is empty. Replace it with fresh coin cell battery.
Led light might also either stay on (i.e. not blinking but constantly on), or it might blink in odd frequency (i.e. there is no clear pace to it) – if this happens change the battery. If the led light is still staying on or the odd pace blinking persists, switch it off, remove the battery and let it rest for a while. Try switching the sensors off and back on once more, if the led light is still constantly on or the odd blinking still continues, the head sensor is very likely damaged and needs to be replaced.
2. Turn sensor off by pressing the on/off-button twice slowly and firmly. Wait to see one long red led-light signal and then no more blinking to ensure the sensor is switched off
How can I access profile’s impact history and impact information in Web User Interface? How do I import data from Web User Interface?
There is lots of information and data on the impacts and forces acting on a head measured in Web User Interface (access it via Browser Access):
How to wear ACT Head Impact Tracker head sensor in a helmet?
Head sensor measures forces on what it is attached to. Hence we strongly recommend attaching ACT Head Impact Tracker head sensor on a head with a tight-fitting head accessory of user’s choosing, also when used with a helmet. Head bands and Docks specifically designed for the head sensor can be purchased in the webstore in www.act-tracker.com.
Place the head sensor so that its head side (i.e. the side with the foam, on/off-button and led-light) is towards your head. Place the head sensor on the back and side of the head, on the more even area after the ear for example. Do not use head sensor on an area where direct impacts may occur, like on a forehead, on the temple, or on the back of your head.
The head sensor can be attached to almost any kind of head accessory or wear with hook & loop (Velcro) -tape, or similar. The back panel of the head sensor has an adhesive surface that you can use by removing the protective film on top of it. We recommend that you use the adhesive surface to attach one piece of hook side of the hook and loop -tape, with which you can attach the head sensor to the ACT Head Impact Tracker headband or other head accessory. Please note that the surface is very adhesive, consider carefully where or what you want to attach to it.
If you consider attaching head sensor to a helmet, refer to your helmet’s User Manual, Owner’s Guide and website. Your helmet’s warranty might be compromised if you attach anything to it. Always follow the helmet manufacturer’s instructions on safe helmet use. Only use a helmet that meets the applicable safety standard when you use a helmet with the head sensor. If you attach sensor on a helmet, the magnitude measurement accuracy might be compromised, the forces acting on a helmet are many cases higher in magnitude to those acting on your head inside the helmet.
In helmet types where it is not possible to use head sensor with a head band underneath (like ice-hockey goalie helmet), we recommend attaching the head sensor on a helmet like this. Or attach the sensor to the hard surface inside the helmet (like on American Football helmet pictured below). Please remember that when the sensor is attached to the helmet, it measures the forces and impacts acting on the helmet, which is not equal to the forces acting on a head inside the helmet. Forces acting on a helmet are typically more violent, and helmet cushions the impacts reaching the head – which is one of the reasons helmets are worn.
Can I change Profile information or move sensor to another Profile?
No you cannot. We recommend to use coding for the profile names such as GP1, GP2, GP3 and so forth. This will protect the privacy of the users impact data and allow you to change sensors from one user to another in a seamless way.
Quick start guide – Head sensor & App
1. Buy a CR2032 coin cell battery for the head sensor.
2. Download ACT Head Impact Tracker smartphone mobile App from Google Play on your smartphone. Please notice that App is for Android 9 or newer Android operating system only, and that the App’s compatibility with all and every smartphone brand and model has not been tested and cannot be guaranteed. Updated list of brands and models tested can be found in FAQ in www.act-tracker.com
3. Ensure location services and Bluetooth® wireless communication are enabled, on and active in your smartphone for the App and always when using it with the head sensor. If your smartphone runs Android 12 or newer operating system, you also must give App the permission to use “Nearby devices”, or App cannot communicate with the sensors.
4. Ensure that your mobile data and roaming (if needed) are enabled, on and active in your mobile device for the App and always when using it with the head sensor(s), or that you are connected to Wi-Fi. If you do not have mobile data or Wi-Fi at your disposal, please use the sensors in Tracker mode, it will decrease their power consumption. Note: when sensors are on Tracker mode, near-real-time delivery of sensor measurements is not functional, you have to download the impacts from the sensor to the App after the session, when mobile device can be connected to mobile data or Wi-Fi.
5. Create User Account in the App. Your email acts as your User-ID. Make sure to store your password somewhere safe.
6. Create Profile in your User Account to which you want to add the head sensor to. Follow App’s instructions on creating Profile. Please note: You cannot remove or change Profile once created.
7. Remove the head sensor from its package. Open the hatch. Add the coin cell battery by carefully sliding it underneath the silver-colored holder bridge as indicated by the arrow on the bridge + side is facing you and away from the electronics.
8. Locate the head sensor’s Serial number also acting as Registration code, which is on the product label underneath the battery hatch. Open the hatch and you can see the white sticker on the lid. Registration code is a 6-digit code on the product label. Please note: you can only register sensor one time, to one profile and user account. Sensor cannot be transferred or removed once added to a profile.
9. Close the hatch by pressing all the sides firmly together to seal the locks on them. Check that the sides are seamlessly connected with each other before the use. Inserting the battery may turn the sensor on, but some components might not turn on. Before the use, switch the sensor off and back on.
10. Turn the head sensor on by pressing the on/off-button once slowly and firmly. The sensor is on when the small red led light next to the button starts to blink in slow frequency. If the led-light blinks in high frequency (in fast pace), the battery is almost empty. Change the battery or ACT Head Impact Tracker might not work as intended. If the light does not come on at all, or the light comes on but it is not blinking, try with a new battery. If the light still is not coming on at all, or the light comes on, but it is not blinking, or light blinks in a random sequence, the head sensor is not working as it is supposed to and should be replaced.
11. When the sensor is on, choose Profile you want to add the sensor to, click on it. Click then the green button next to “Sensors”, and then “Add Sensor” button. The App has found the sensor when it says on it: “Found 1 sensor”. Click “Continue”. The App is connected to the sensor when it shows “Connected to 1/1 sensors”. Add Registration code to the line under the text. Click “Continue”. If the App cannot find any sensor, switch the sensor off and back on, and try again. If the App finds more than one sensors, switch off all the other sensors than the one you want to register and try again.
Please note: you have to be connected to Wi-Fi or have mobile data connection at use to register a sensor. If the connection is very weak, or gets disconnected while the registration is ongoing, the sensor might not be registered correctly, and will not function. Please ensure the connection during the registration is strong and has no disconnections to it.
12. Choose the sport / discipline the sensor is primarily used for > Click “Continue”
13. Name your sensor or leave the line blank, and click “Finish”.
When registration is complete App will confirm “Registration is successful”. Drop the sensor on the table/floor once to test that data will come through and the registration has been successful. and your ACT Head Impact Tracker is ready for action.
14. In the end of each session of use, make sure to switch off the sensor by pressing on/off-button slowly and firmly twice. Wait for three short led-light blinks to indicate the sensor is switched off. Doing this will prevent impacts from handling and transportation to be recorded to your impact history. Also, it will save energy and prolong your battery lifetime.
IMPORTANT USAGE INFORMATION!
Head sensor is always measuring when it is on. And it does not know when it is on a head and when not. You will get (potentially multiple) false positive measurement events from handling and transportation unless you are careful and only switch the sensor on just when you are about to enter the pitch/slopes/path/whatever your playground. The same when your session is over, always immediately turn off the sensor at the earliest possible moment. If, and when, false positive events occur, you can go and mark them as Faulty in Browser Access’ Web User Interface.
See detailed illustrated instructions in User Manual.
What smartphone devices are compatible with ACT Head Impact Tracker?
Last updated: 19th of September 2023
LIST OF MOBILE DEVICES’ FUNCTIONALITY WITH ACT HEAD IMPACT TRACKER
Tested and found working brands (models, Android OS)
1. Samsung Galaxy A21s (AOS 12)
2. Samsung Galaxy A41 (AOS 11)
3. Samsung 9+ (AOS 10)
4. Samsung A40 (AOS 11)
5. Samsung S21 Ultra 5G (A13)
6. Motorola e20 (AOS 11)
7. OnePlus8 (AOS12)
Occasional problems with establishing and maintaining connection between the head sensors and mobile devices (no notification to the App regarding) were recorded:
– Samsung phones: a.) in some models Bluetooth® wireless connection was slow, even disconnected, if the mobile phone’s screen is switched off (= not lighted). The connection should be re-established and information from the sensors delivered when the screen is switched back on (=lighted) if the sensor(s) are in the reach of Bluetooth® wireless technology. b.) In all models pop-up window with list of devices for paring appears when Bluetooth® wireless technology is switched on. When this happens, just click “Continue” to close the window. No paring is needed, nor appearing nor choosing it on the list. Also in few occasions the phone just disconnected Bluetooth® wireless connection. If the listening sensors just stops, turn Bluetooth® wireless connection off and back on, this fixed the problem.
NOTE: If you have Android 12 or newer operating system, you must give App permission to use “Nearby Devices”, or ACT Head Impact Tracker will not work as intended.
Tested and found not working as intended (brands and models, Android OS) when using passive scanning:
USE ACTIVE SCANNING. In ACT app menu (three bars on the left hand upper corner) click “Scan Sensors”. At the moment this only works on one sensor at a time, i.e. as soon as one sensor has sent its latest impact, the scanning connection ends. To reactivate scanning click “Scan sensors” again. Active scanning is not recommended to be used when listening to multiple sensors (i.e. by teams and clubs).
8. Xiaomi Redmi 9a (AOS 10)
The connection between the sensors and the mobile phone was disconnected when the App was not on, on top of the open Apps and/or screen was switched off (not lighted).
9. OnePlus Nord N100 (AOS 11)
10. OnePlus8 (AOS13)
Other brands and models have not been tested, and cannot be granted to work, or work as intended with ACT Head Impact Tracker. (If your device is not on the list, it does not guarantee it is functional, or that is not. We just have not tested it yet.) Passive scanning is likely not working, it is recommended to USE ACTIVE SCANNING. In ACT app menu (three bars on the left hand upper corner) click “Scan Sensors”. At the moment this only works on one sensor at a time, i.e. as soon as one sensor has sent its latest impact, the scanning connection ends. To reactivate scanning click “Scan sensors” again. Active scanning is not recommended to be used when listening to multiple sensors (i.e. by teams and clubs).
iOS App is not yet available. The plan for iOS App launch is in the beginning of 2024.
How to add sensor to profile on your user account
To add and use ACT Head Impact Tracker head sensor, you have to add it to a Profile on your User Account. Note: you cannot change Sensor information, nor move or remove Sensor once added to Profile. Add head sensor to a Profile like this:
You are now all set and good to go. Sport safely!
How should I wear it with the head band? How to attach head sensor to ACT Head Impact Tracker head band?
Place the head sensor only in a location where impacts do not occur. Always place the head sensor so that its head side (i.e. the side with the foam, on/off-button and led-light) is towards your head.
If you use a head band, the head sensor is to be placed in between the head and the head band. This is how it should look like with the head band.
I received hook and loop tape with the head sensor and the head band, how should I use it?
Place the sensor on the table head side down and back side up. There is glue tape area on the back side of the head sensor which is covered by a yellow cover foil (pic 1.). If you want to use hook and loop tape to attach the head sensor, take a piece of hook tape, remove the covers from the head sensor’s glue area and that of hook tape piece. Add the hook tape on top of the glue area on the head sensor as show in the 2nd picture.
1. 2.
Attach the loop-side of the tape to the head wear you are planning to place it and to the location where no impacts occur. The loop-side is already there on the ACT Head Impact Tracker Headband and Dock, hence no need for using loop-tape with them.
Attach the head sensor back side hook area to the loop area of the head wear, ensure the head side of the head sensor is towards your head. Switch the head sensor on and off you go.
What happens if I want to give away or sell my head sensor to someone else?
You can only register the head sensor once and to one User Account and Profile only. The head sensor cannot be removed or transferred to another User Account or Profile after registering it. So, selling or giving the head sensor away does not work as you cannot remove the sensor from one User Account and register it to another, nor can you transfer the sensor from one profile to another.
Can I re-register my head sensor, or move it to another user account or profile?
No, you cannot.
When does the head sensor’s one-time registration code expire?
There is no expiration date as such, but each code can be used only once, one time to register the head sensor to your user account and profile there.
Is there a temperature range for the head sensor to work properly?
The temperature range for the head sensor electronics is approximately from -10C to 40C. Please be aware that cold temperature may impact the battery and cause it to drain faster.
Is the head sensor waterproof?
No. It is not suitable for water sports or under water use.
When the head sensor’s hatch is properly closed and head sensor’s side seams sealed, the head sensor is “weather and sweat proof”.
Can I deactivate the automatic switch off?
No, you cannot.
Why is there an automatic switch off after 180 minutes in the head sensor?
The head sensor records all the time when it is switched on. It is not possible to remove individual impacts from your impact history, even if they are so-called false positives (i.e. happened when the head sensor was not on the head). Hence, we included an automatic switch to help minimize so-called false positive impacts being recorded for example during transportation and handling.
How do I know how much “juice” there is left in my head sensor’s battery?
There are two ways to find out if the level of battery is too low:
1. Led light on the head sensor
Battery level is too low if when you switch the head sensor on, the led light starts blinking in fast pace. Change battery, or ACT Head Impact Tracker does not work as intended.
If the led light does not come on at all, the battery is empty. Replace it with fresh coin cell battery.
Led light might also either stay on (i.e. not blinking but constantly on), or it might blink in odd frequency (i.e. there is no clear pace to it) – if this happens change the battery. If the led light is still staying on or the odd pace blinking persists, switch sensor off, remove the battery and let it rest for a while. Try switching the sensors on, off and back on once more, if the led light is still constantly on or the odd blinking still continues, the head sensor is very likely damaged and needs to be replaced.
2. Battery level indicator in the App
In the App you can find battery level indicator for the sensors registered to it. You can find the indicators in the “Sensors” section next to each head sensor listed. How to update the App’s battery levels: Switch the head sensor on, open the App and see that connection between is established (little ACT-icon appears on the upper corner of your smartphone screen), connection will update the head sensors’ battery level indicator within 2 minutes.
Can I use other devices featuring Bluetooth® wireless technology while using the head sensor?
Yes. The head sensor does not conflict with other Bluetooth® wireless technology connections. The connection is not on all the time, it only takes place in short bursts when needed.
How does the head sensor connect with the mobile device with app?
ACT Head Impact Tracker head sensor features Bluetooth® LE (low energy) wireless technology.
What types of electronics are there in the head sensor?
Head sensors have an accelerometer for linear forces measurement. ACT Head Impact Tracker head sensor Pro also has gyroscope for angular movement measurement.
There is no GPS in the head sensor.
Can I use it for my toddler learning to walk?
No. The head sensor is not suitable for children under 36 months of age. Keep the head sensor out of reach of small children and animals. Contains small parts. Risk of suffocation!
Coin cell battery is a risk for small children, and it should be kept out of reach of children. Swallowing a coin cell battery can lead to chemical burns, perforation of soft tissue, even death. If ingestion or inserting a coin cell battery into any body part is suspected, seek medical attention immediately. More information on the safety and toxicology of the coin cell battery on the battery’s manufacturer’s website or in the web.
Is head sensor safe to use?
We created ACT Head Impact Tracker to improve the wellbeing and health of athletes. However, some risks may be related to the head sensor use.
The head sensor contains hard parts. These are the electronics, i.e. plastic circuit board with electronic components on it, and a standard CR2032 coin cell battery. The risks can be minimized by placing the head sensor in a location where direct impacts do not occur. Do not place the head sensor on the forehead, on the temple or on the back of your head for example.
The head sensor is not suitable for children under 36 months of age. Keep the head sensor out of reach of children. Contains small parts. Risk of suffocation!
If swallowed, a coin cell battery is a risk for small children and animals, and it should be kept out of reach of children and animals. Swallowing a coin cell battery can lead to chemical burns, perforation of soft tissue, even death. If ingestion or inserting a coin cell battery into any body part is suspected, seek medical attention immediately. More information on the safety and toxicology of the coin cell battery on the battery’s manufacturer’s website or in the web.
The plastic casing is made of silicone, and the foam on the head side is closed cell EPDM. Our head sensor is in compliance with European Union Directive (2011/65/EU) on the restriction on the use of certain hazardous substances in electrical and electronics equipment (RoHS).
The head sensors are CE-marked. CE marking is an administrative marking that indicates conformity with health, safety, and environmental protection standards for products sold within the European Economic Area (EEA).
Do I need a registration code for the head sensor to register it in the app?
Yes, you need to enter a head sensor registration code in the App for each head sensor you add. You can find the unique registration code (also acting as serial number of the head sensor) on the product label, which is a white sticker underneath the battery hatch. Open the hatch and you can see the white sticker on the lid. Registration code is a 6-digit code on the product label.
Please note: The registration codes are unique to each head sensor. Each head sensor comes with a one-time registration code. This means you can only add the head sensor once and to one User Account and Profile only. The head sensor cannot be removed or transferred to another User Account or Profile after registering it.
Should I be concerned about radiation from the head sensor?
The head sensor uses Low-Energy Bluetooth® wireless technology for the communication and is rated safe for its use. The head sensor is also CE marked.
How to empty impact information from head sensor’s memory?
Every once so often the impact information is not being delivered from the sensor to the App and Cloud. This means the impact information is not featuring in the App. The most common reasons are:
– Sensor is off, or on Tracker mode
– Sensor is out of reach of the smartphone’s Bluetooth® wireless communication
– Bluetooth® wireless communication or Location Services are disabled
– If you have smartphone with Android 12 or newer operating system, you also must give App permission to use “Nearby devices”, or ACT Head Impact Tracker does not work as intended. (If your phone does not have “Nearby devices” functionality, the permission is not needed)
– Smartphone has no or weak mobile data connection, or Wi-Fi connection is weak or not available
Whatever the reason, it is a great idea to empty impact information from the sensor on regular basis and do it every time before you are about to run out of battery or exchange it (impact information time stamps might be affected by the sensor’s power outage). This is how you can do it:
How can I access profile’s impact history and impact information in App?
There is lots of information on the impacts and forces acting on a head measured, calculated and available. To get the impact information in the App:
What is Tracker mode, and how to activate and deactivate it
NOTE! Tracker mode is available in head sensor version 1.2, and later versions, and in Pro version. Head sensor version 1.2. was launched in September 2022, hence if you purchased yours before that there is no Tracker mode functionality to them.
We recommend using Tracker mode if you do not have Wi-Fi connection or mobile data connection available throughout the session. It is not necessary to use Tracker mode, the sensors will save unsent data in them. But using Tracker mode will save energy and prolong the battery’s life span.
What happens when the sensor is on Tracker mode is:
1. When the sensor detects an event with 10g or over, it saves the event information. It makes no attempt to deliver the data to the App. This means real time impact information will not be available.
2. After the session switch all sensors off and switch them back on one by one so that the sensor is in the proximity to the mobile device with the App – which is connected to Wi-Fi or has mobile data (and roaming if needed) connection. The sensor will transfer all the impacts from its memory (depending on the number of impacts, this can take from few seconds to approximately 1 minute). It is recommended to do this every time before the battery is changed, after the battery is changed the time stamp of impacts saved prior the battery change will not be accurate.
To activate Tracker mode:
1. Switch the sensor on by pushing on/off button once. Check that the LED light starts blinking in slow frequency to indicate that the sensor is on (now on a normal mode).
2. Push the on/off button once while keeping the button pressed for about 2 seconds (keep the button pressed for 2 seconds) until the LED light blinks 3 long blinks and then starts blinking in slow frequency (1 blink / 5 sec). Tracker mode is activated, no real time impact data will be sent, and impact information will be saved in the head sensor’s memory. Please note: you first have to switch the sensor on and only then Tracker mode can be activated.
Push the on/off button once while keeping the button pressed for about 2 seconds (keep the button pressed for 2 seconds) until the LED light blinks 3 long blinks and then starts blinking in slow frequency (1 blink / 5 sec). Tracker mode is activated, no real time impact data will be sent, and impact information will be saved in the head sensor’s memory. Please note: you first have to switch the sensor on and only then Tracker mode can be activated.
To deactivate Tracker mode:
1. Push the on/off button once while keeping the button pressed for about 2 seconds so that you can see the LED light activating (then release the button).
2. Led light blinks 4 long blinks to indicate Tracker mode is deactivated and sensor is back on normal mode (the slow continuous LED light blinking). Alternatively, you can turn off the sensor when it is on Tracker mode.
Switching the head sensor on and off
Inserting and removing the coin cell battery
How to add hook tape to the head sensor
You can attach the head sensor with hook tape on your head with ACT Head Impact Tracker head band or dock, or attach it to a helmet or other type of chunky headwear. See detailed instructions in dedicated instruction sheets.
How to attach head sensor to ACT Head Impact Tracker head band?
Congratulations for purchasing ACT Head Impact Tracker head band for attaching head sensor. It is super-easy to use:
How to attach a dock and head sensor to your skinny hair/head band
Head sensor setup and wear
1. Take out the head sensor’s back side with added glued surface on it.
2. Take out one piece of the hook tape you received with the head sensor, or that came with ACT Head Impact Tracker head band or dock you purchased.
3. Remove the yellow cover tape on the sensor’s glue surface and the white cover on the hook tape piece.
4. Place the hook tape piece directly on top of the sensor’s glue surface area. Use only one piece of the hook tape at the time, save the second piece you might have received for later use if needed.
5.The head sensor is placed as shown in the picture. Place the sensor next to the head, in between the head and head band. The headband logo shows to the outside, the head sensor is on the head side, underneath the head band.
6. Place the head sensor only on a location where no impacts occur.
How to attach the head sensor to a helmet? How to add hook tape to head sensor?
Attach a hook side of the hook & loop (Velcro) tape on your head sensor back side. You can attach head sensor with hook tape on ACT Head Impact Tracker head band or dock, which have Loop-sides in them, or attach head sensor to a loop-side tape you insert to a helmet or other type of chunky headwear.
To attach hook-tape on the head sensor:
IMPORTANT INFORMATION!
-The sensor is measuring on what it is attached to. If you attach it to the helmet, it will measure the forces and impacts on the helmet, which is different from the forces acting on your head underneath the helmet.
-If you consider attaching the head sensor to a helmet, refer to your helmet’s User Manual, Owner’s Guide or corresponding document to verify if it is possible. Always follow the helmet manufacturer’s instructions on safe helmet use. Only use a helmet that meets the applicable safety standards when you use a helmet with ACT Head Impact Tracker head sensor.
-Attach the sensor on a hard and even surface, head sensor preferably inside the helmet. Do not modify the helmet any way to fit the sensor to it, or you might loose the warranty of the helmet, or some of the safety features on it.
-We recommend attaching the sensor with hook and loop tape so that the sensor can be removed easily for the battery exchange and other handling.
-Place the head sensor only in a location where direct impacts do not occur, do not wear on a forehead, back of your skull or on the temple for example.
-If you feel discomfort or pressure, the head sensor is not in a right location.
-To improve the measurement accuracy on the forces and impacts acting on a head, we recommend using a head accessory to place the head sensor below the helmet.
How to wear ACT Head Impact Tracker head sensor
Head sensor measures forces on what it is attached to. Hence we strongly recommend attaching ACT Head Impact Tracker head sensor on a head with a tight-fitting head accessory of user’s choosing, also when used with a helmet. Head bands and Docks specifically designed for the head sensor can be purchased in the webstore in www.act-tracker.com.
Place the head sensor so that its head side (i.e. the side with the foam, on/off-button and led-light) is towards your head. Place the head sensor on the back and side of the head, on the more even area after the ear for example. Do not wear head sensor on an area where direct impacts may occur, like on a forehead, on the temple, or on the back of your head.
The head sensor can be attached to almost any kind of head accessory or wear with hook and loop (Velcro) -tape, or similar. The back panel of the head sensor has an adhesive surface that you can use by removing the protective film on top of it. We recommend that you use the adhesive surface to attach one piece of hook side of the hook and loop -tape, with which you can attach the head sensor to the ACT Head Impact Tracker headband or other head accessory. Please note that the surface is very adhesive, consider carefully where or what you want to attach to it.
If you consider attaching head sensor to a helmet, refer to your helmet’s User Manual, Owner’s Guide and website. Your helmet’s warranty might be compromised if you attach anything to it. Always follow the helmet manufacturer’s instructions on safe helmet use. Only use a helmet that meets the applicable safety standard when you use a helmet with the head sensor.
Note: If you attach sensor on a helmet, the magnitude measurement accuracy might be compromised, the forces acting on a helmet are many cases higher in magnitude to those acting on your head inside the helmet.
How long does the battery last?
CR2032 coin cell battery will last in ACT Head Impact Tracker head sensor anything between 100-200 hours on-time (i.e. when the sensor is on), depending on the battery used. Same battery will last in ACT Head Impact Tracker Pro between 60-80 hours.