Intermec 073290-001 User Manual

Power management software on the PXA255 uses the battery voltage and 
temperature data for temperature-compensated fuel gauging and low-
battery detection. Three levels of battery status are indicated through an 
icon in the status bar: 

67% to 100% charge remaining 

(No icon displays) 

34% to 67% charge remaining 

 

1% to 33% charge remaining 

 

0% charge remaining 

 

The first three battery status thresholds are defined in software; the final 
critically low battery threshold is based on hardware comparator U36. 

Software 2/3 
capacity threshold 

< 0°C 
10°C 
20°C 
30°C 
40°C 
50°C 

<= 7.73V* 
<= 7.78V 
<= 7.83V  
<= 7.87V  
<= 7.92V  
<= 7.97V  

>= 7.83V* 
>= 7.88V 
>= 7.93V  
>= 7.97V  
>= 8.02V  
>= 8.07V  

Battery at approximately 67% 
capacity;  “2/3” battery status 
icon is displayed. 

Software 1/3 
capacity threshold 

< 0°C 
10°C 
20°C 
30°C 
40°C 
50°C 

<= 7.07V* 
<= 7.16V 
<= 7.25V  
<= 7.35V  
<= 7.44V  
<= 7.53V  

>= 7.17V* 
>= 7.26V 
>= 7.35V 
>= 7.45V 
>= 7.54V 
>= 7.63V 

Battery at approximately 33% 
capacity; “1/3” battery status 
icon is displayed. 

Software low-
battery threshold 

< 0°C 
10°C 
20°C 
30°C 
40°C 
50°C 

<= 6.4V* 
<= 6.54V 
<= 6.68V  
<= 6.82V  
<= 6.96V  
<= 7.10V  

>= 6.5V* 
>= 6.64V 
>= 6.78V  
>= 6.92V  
>= 7.06V  
>= 7.20V  

Battery at 0%; “Empty” 
battery status icon is displayed, 
and the red LED turns on. 

Critically low 
battery 

< 0°C 
10°C 
20°C 
30°C 
40°C 
50°C 

<= 5.82V** 
<= 5.96V 
<= 6.15V 
<= 6.31V 
<= 6.45V 
<= 6.55V 

>= 6.41V** 
>= 6.55V 
>= 6.69V 
>= 6.80V 
>= 6.88V 
>= 6.94V 

Critically low battery. U36 
asserts interrupt 
BATT_FAULT_IRQ to start 
a Suspend. This state must be 
exited before the CK30 is 
allowed to resume. 

*  These temperature ranges are approximate because the Vbat temperature compensation is not calibrated at 
manufacture.  Also, because the battery level is averaged over 10 samples at 3-second intervals, it may take up to  
30 seconds for a threshold crossing to take effect. 

**  These temperature ranges are approximate because the Vbat temperature compensation is done in hardware.