Solar panel to support battery life without charging it

[weeleebee]

@PerryBebbington

Make sure the solar panel output voltage cannot exceed the maximum allowed input voltage to the mower.

I guess this is the last unkown to me.
Do I have to worry about the panel going over 32v even if it should always be a under load?
If so, what can I do to clamp the panel voltage? Here is where I start to get lost.