If your Ooze Cart battery is flashing red, it could be for a variety of reasons. Here are some possible causes and solutions:

1. Connection issue: If the battery is flashing red and you're unable to use the pen, it could be a connection issue. Make sure that the cartridge is securely connected to the battery, and try wiggling it gently to ensure a good connection. If the problem persists, try cleaning the connection points with a dry cloth.
2. Using a non-compatible product: The Ooze Cart battery is designed to be used with specific types of cartridges. If you're using a cartridge that is not compatible with the battery, it could cause the battery to flash red. Make sure to use only cartridges that are compatible with the Ooze Cart battery to avoid any issues.
3. Needing to be charged: If the battery is flashing red and you've recently used it, it could simply be that the battery needs to be charged. Connect the battery to the charger and allow it to charge until the light turns green. This usually takes a few hours, depending on the battery level.

If none of these solutions fix the problem, it could be a sign that the battery is damaged and needs to be replaced. In this case, you'll need to contact Ooze customer service for further assistance.

We hope this information helps resolve your issue with the Ooze Cart battery flashing red.