My DC-UPS - done right ? Advice needed
I am working on something similar.  I have LEDs that run on 48VDC. I have a 48v supply and also supplied by solar panels with lead acid batteries. 

I have not put it into operation yet but I have the diode OR worked out.  I do not use Schottky Diodes but rater an Ideal Diode Controller from Linear Technologies.  They replace the schottky diodes to reduce their voltage and minimize heat.

Charging batteries with a resistor as the current limiter is not good for the batteries.  How bad it is depends on the batteries.  I would NEVER do that with my Lead Acid batteries.  That is just not the way to charge a battery. My batteries are being charged with a $400 Max Power Point Tracking (MPPT) charger which is solar powered.











I bought this Linear Tech Ideal Diode Controller Eval Board 

which uses this Linear Tech Controller:
LTC4355 High Voltage Ideal Diode-OR with Input Supply and Fuse Monitors





My Vin1 will be the lead acid batteries being charged by the solar panel.  Fully charged they are about 56+ volts.

My Vin2 will be a 48V power supply tweaked down to around 44V, depending on the colors of the grow light LEDs. 







When the batteries voltage drops below the power supply voltage, the controller board will switch over to the power supply.  When the batteries charge back up to greater than the power supply voltage, the LTC4355  board will switch back to solar/batteries.