The DC solid state relay is a high current relay that can be used to join 2 batteries in parallel or used as a standalone battery protection device.
A push button SPST switch is provided to turn on and off the solid state relay. When required to be connected to parallel batteries, you will need to use 2 relays. We do sell the wire harnesses for parallel battery configuration.
Alternatively, you can use the auto-switching solid state relay to perform current and voltage sensing such that when batteries in parallel are connected to it, it will automatically discharge from the higher voltage battery pack until the 2 battery packs are balanced out.
This intelligent switch allows you to connect 2 battery packs of different capacities in parallel (but of the same voltage) as the intelligent solid state relay will be able to selectively discharge each battery pack. It also prevents any current backflow from one battery pack to the other lower voltage pack, hence preventing damage to your battery packs.
Heres a video explainer to explain why you would need a pair of solid state switches when connecting 2 batteries:
To be used as a standalone device, you can use the SPST switch provided to turn on/off the battery especially when leaving in storage for a long time. This is to prevent any leakage of current from your ebike or e-scooter electronics hence slowly draining out your battery over time.