Does it really matter?
You’re dropping $1000 on a 100ah battery (presumably) and plan to sip power to the point that you can keep a single battery topped up with a single 100W panel?
First, if you only use what that little panel can replenish daily under normal conditions, you’re basically using no power.
What can you run on 80-85 watts for say 12 hours (being generous)?
Sounds like you’re confused and think a $1000 battery is a magic solution to free power.
It’s only a magic solution to making your wallet lighter, unless weight is that critical.
In which case, no, a 100W panel won’t keep up unless the battery is just there for looks and not use.