Am hoping to try one or two of these on my offgrid solar power system soon. They can be purchased without the power supply for USD$99 plus freight. I am hoping I can power them directly using the DC output from my '24' volt LifePo4 batteries which in practice operate between 28-26 volts dc. Has anyone tried this and does it work or will there be problems with the voltage not being precisely 28v all the time?