efficiency
In the name of efficiency be careful of just what efficiency your going after.

The system you propose is a balance of many efficiency's.
Battery cost
Battery Life.
Fuel cost.
System cost etc.

Fuel efficiency = Energy efficiency charging a battery best below 80% SOC (which you know)
Battery life is best when SOC is above 80% even better above 90%...
Battery cost efficiency means maxing out battery capacity (how low in SOC (20%)).
Battery life is best when minimal capacity is used. (Battery charge/discharge cycles)
Both effects to Battery life are controlled by a condition know as sulfating.

Sulfating
All about SOC over time spent with low SOC and how long since last equalizing charge. Timer is assumed to reset after an equalizing charge.

Is Your daily energy use predictable?

By knowing at end of day the battery is going to sit until morning for sun, during the last hours of battery use charge it to 50% to minimize time at low SOC.
The more time spent with low SOC the more frequent an equalizing charge is needed to max out battery life.

Battery can be charged at 1C rate, only do this after studying the dangers of doing so.

Books have been written on the care of lead acid batteries, this only hits on the high points.
Be careful of what you read, many urban legends out there on the care and feeding of batteries, much is BS. Find real sources backed by tested data to draw any conclusions from. In others words do not take my word for this! Sorry but the price is a system that does not meet your needs... which can you afford?

The other balance is system design of wind / solar, are they sized to supply needs or will the generator be supply a daily boost to the system?
Solar panels have a present cost vs fuel a future cost, all part of the balance of system design.