Unplug temp sensor from the Renogy-40 amp Solar Charge Controller. Leaving it plugged in can skew charging. It is used for Lead Acid batteries and not Lifepo4. These settings should get you started.
If at all possible, operate at moderate temperature and avoid deep discharges; charge as often as you can (See BU-403: Charging Lead Acid) The primary reason for the relatively short cycle life of a lead acid battery is depletion of the active material.
If you connect two lead acid batteries together for loads only (somewhat difficult to achieve), the battery with the greater charge will try to charge the lower one. However, they will eventually stay equal but this will not last.
Despite being three years old, the 160AH lead acid battery in this setup is still functional. It is currently hooked up to a 1KW inverter and helps power my house partially during power outages.
The primary reason for the relatively short cycle life of a lead acid battery is depletion of the active material. According to the 2010 BCI Failure Modes Study, plate/grid-related breakdown has increased from 30 percent 5 years ago to 39 percent today.
The steps used in charging of an open or vented lead acid battery are named: main charge, used for charging the battery up to a voltage level when gassing starts and the voltage rises. (The voltage limit is 2.39 V at 25°C and 2.33 V at 40°C). top-up charge, to reach the 100 % state of charge from a level of 90 - 95 %.
Except for protecting the battery from abuse situations, most of the regulators have built-in charge controllers. It is always important to investigate the type of charging procedure and to check if control parameters like temperature compensation for the battery temperature is incorporated. A good lead acid battery charger should include: