I am so sorry this was never answered! I had to take a step back from social media for a couple of weeks to keep up with my marketing responsibilities (which sounds ironic), and it appears I missed this message and another from you in another thread which I will now answer.
There will be a special cable that you can purchase that will allow you to connect to a 12V battery backup, like the original IceCap model. You won't be able to use a simple Y-cable as it does not have the GX-12 connectors which are required by the WaveEngine to keep its IP65 rating. Unfortunately, the cable was not available when the WaveEngine was released.
We are also working on a HYDROS battery backup.

I'll follow up with the HYDROS team to see how both of these are coming along. Would you mind emailing me at
[email protected] so we can continue the conversation?