Solis 5K-48-5G charging hot tub and not batteries

[Hendo127]

Hi everyone, New to the site and got some amazing information already from it.

My question is how do i charge my hot tub during the cheap tariff 0030-0430 without the charge coming from my batteries.( im happy the batteries don't need charging as they have enough to last me through the night until the sun comes up)

Is this possible to do ?

Thanks in advance