The problem is charging lithium iron batteries for "maximum Cycles" with a solar charge controller wile using loads?
I have a PowerSonic 45 amp hour LiFePo4 battery for my Caravan house battery. I am powering it with a 100 watt solar panel and a Pulse Width Modulation "PWM" charge controller. My loads are a small multi-voltage refrigerator that draws about 2.5 amps at 13.5V with appx 50% duty cycle, a Sony car stereo, some LED lights and other small 5 VOLT USB loads, phone and tablet charging.
Currently I am using a factory programmed PWM charge controller that should limit the bulk charging voltage to 14.2 Volts but it doesn't and the voltage Rises to 16 volts where the battery management system takes over and cuts the voltage to battery bank to 13.7V. The load low voltage cut out is set to 12.1V, The maximum solar output is theoretically 7.1 amps at 14 volts but because it's not a maximum power point controller realistically it's appx 5.6 amps maximum which is well below the recommended 20 amp maximum charge rate.
I have ordered an EP solar Landstar programmable PWM charge controller for the solar panel and plan to set the bulk charging rate at 14.1 volts and the trickle charge rate to 13.3 volts and the Load low voltage cut out to 12.5 volts.
I have also ordered a buck boost converter and plan to connect it to the Caravans auxiliary output set to 13.7 volts at 8 amps for supplemental charging while driving. I hope this will give me a Charge Profile to extend the Maximum Charge Cycles for my LiFePo4 battery's application.
It's my understanding that deep discharging and charging to high reduces the cycle lifespan of lithium iron batteries.
What Bulk-charge and float-trickle charge voltages should the Charge controller and buck-boost be set to for maximum cycle life?
Thanks for your help