RE: Class A Troubleshooting for us Newbies
Leveling system requires the vehicle to be in Park and emergency brake to be set. For power try it with the engine running.
RE: Upgrading to a better phone
Nokia 6.2 unlocked. Works on AT&T/T-Mobile/MetroPCS/Cricket/Mint. $250 on Amazon.
https://www.amazon.com/Nokia-6-2-Unlocked-Smartphone-T-Mobile/dp/B07XW28MHX
An AndroidOne phone, No carrier or Nokia bloat.
RE: Power gear hyd levelers low power
Bearings on the leveling motor go bad. If your reservoir and motor are behind the front grill water can get to the motor bearings. Mine started squealing, replaced the motor.
RE: Battery charge
Your charger should supply a float voltage of around 13.2 -13.4 volts for a lead acid battery. If that 12.5 voltage was measured with the charger on and the battery connected the float voltage is to low from your charger.