A blinking red light on your vape cartridge battery typically indicates a few potential issues:

1. Low Battery
Charge Needed: The most common reason is that the battery is low on power and needs to be charged.
2. Connection Issues
Poor Connection: Sometimes the connection between the cartridge and battery isn't secure. Make sure they’re properly screwed together.
Dirty Contacts: Check for any debris on the contacts that could interfere with the connection.
3. Short Circuit
Faulty Cartridge: A short circuit in the cartridge can cause the battery to blink red. If possible, try a different cartridge to see if the issue persists.
4. Overheating
Protection Feature: Some batteries have a protection feature that causes the light to blink if the device overheats.
5. Malfunction
Battery Issue: If the battery is malfunctioning, it might need to be replaced.
Conclusion
If your battery is blinking red, start by charging it. If the issue continues after charging and checking connections, consider testing with a different cartridge or contacting the manufacturer for support.