Polar CS300 User Manual

     39

ENG

Wrist Unit Battery
Do not open the wrist unit yourself. To ensure water resistance properties 
and the use of qualifi ed components, the wrist unit battery should be 
replaced by an authorized Polar Service Center only. At the same time, a 
full periodic check of the cycling computer will be done.
Note: 
• 

Speed Sensor Battery
Contact your authorized Polar Service Center to replace the speed sensor. 

Transmitter Battery
If your transmitter stops working, it might be due to the battery running
out. To change the battery, you need a coin, sealing ring, and battery
(CR 2025).

1.  Open the battery cover of the connector with a  
 

coin by turning it counter clockwise from CLOSE  

 to 

OPEN.

2.  Remove the battery cover, lift the battery and  
 

replace it with a new one. 

3.  Remove the sealing ring of the battery cover and  
 

replace it with a new one.

4.  Place the negative ( -) side of the battery against the bottom.
5.  Place the cover with the arrow pointing to OPEN. Make sure that the  
 

sealing ring is placed correctly in its groove.

6.  Gently press the cover deep enough so that its exterior surface is on  
 

the same level as the connector’s surface.

7.  Turn the cover with the coin clockwise until the arrow points to CLOSE.  
 

Make sure that the cover is closed properly!