FSA 90 R
English
19
During Operation
The green LEDs glow continuously or 
flash to indicate the state of charge.
If the LEDs on the battery flash or glow 
red – see "If the red LEDs glow 
continuously / flash".
If the red LEDs glow continuously / flash
3901BA016 KN
80 - 100 %
60 - 80 %
40 - 60 %
20 - 40 %
0 - 20 %
A 1 LED glows 
continuously 
red:
Battery is too 
hot
1) 2)
/cold
1)
1)
When charging: Charge process 
starts automatically after the battery 
has cooled down / warmed up.
2)
During operation: Power tool cuts 
out – allow battery to cool down; it 
may be necessary to take the 
battery out of the power tool for this 
purpose.
B 4 LEDs flash 
red
Malfunction in 
battery 
3)
C 3 LEDs glow 
continuously 
red:
Power tool is too 
hot – allow it to 
cool down.
D 3 LEDs flash 
red
Malfunction in 
power tool 
4)
3)
Electromagnetic interference or 
fault. Take the battery out of the 
power tool and refit it. Switch on the 
machine – if the LEDs continue to 
flash, the battery has a malfunction 
and must be replaced.
4)
Electromagnetic interference or 
fault. Take the battery out of the 
machine. Use a blunt tool to 
remove dirt from the contacts in the 
battery compartment. Refit the 
battery. Switch on the power tool – 
if the LEDs still flash, the power tool 
has a malfunction and must be 
checked by a servicing dealer – 
STIHL recommends an authorized 
STIHL servicing dealer.