if your partner has immunity (hep b surface anti-body) to hep b virus, then your partner can not be infected with hep b virus, irregardless of your status.
But always ALWAYS get vaccinated then no need to worry at all
My husband has hep b and his specialist Dr said it is not transmitted via saliva no matter what viral load is... It has to be contaminated with blood... He also said undetectable dna means you can not transmit to others.... People on this forum may disagree.....