Spot welder?

Mesh node?

Lifting weights?

Backup UPS for your node and router?

As they are Gel, be carful not to go to high a voltage in the charge (check spec sheet for specifics). However gel can be installed in any orientation as the lead acid is suspended in it. Also they don't gas hydrogen like flooded typical lead acid while charging.


 

 Those could be a very hefty supply for a backup system.  

 Electric chair 

 Two 12V batteries can be effectively used in parallel to double the capacity while maintaining the same voltage. This setup is ideal for applications like powering a trolling motor, RV systems, or other devices requiring extended run time without increasing voltage. To connect them, wire the positive terminals together and the negative terminals together, ensuring you maintain a 12V output with increased amp-hour capacity. This configuration allows for longer usage without depleting the batteries quickly, making it suitable for activities like fishing or camping.