| Not heating | 
Low battery | 
Fully charge before use | 
| Power button unresponsive (while charging) | 
Device is connected to power | 
Unplug and try again | 
| Power button unresponsive (damaged) | 
Power button failure | 
Contact customer support | 
| Shuts down halfway during use | 
Battery not fully charged / battery aging | 
Charge fully or contact hello@ocoopa-uk.co.uk
 | 
| Shorter heating duration | 
Low ambient temperature | 
Wrap with cloth to keep warm; or battery life may be reduced | 
| Charging takes too long | 
Extreme temperature environment | 
Charge in an environment of 32°F–104°F (0–40°C) | 
| Cannot charge (LED not on) | 
Poor contact / unstable power supply / damaged cable | 
Check connection, replace cable or power source; if issue persists, contact support | 
| Phone not charging | 
Loose connection or wrong port | 
Reconnect or switch USB port; note: heating stops when charging a phone |