Renogy 20A dc to DC report
Hi All, Regarding the Renogy 20A DC to DC Battery Charger 12V, the unit puts out 20 amps, but draws 30 amps when doing so. This is the result of bench testing.
Forum Discussion
"Rated Max power is 250 watts."
Yes but what is that rating based on? 20 amps output means 250/20 = 12.5 volts.
You can choose a charging profile that is 14.7v at 20 amps = 294w.
That is what it is supposed to do, never mind its "rating" of 250w. I have no idea why they have that in their specs. It is like those converters that are "rated" for when they are at 13.6v and not when they are at 14.4v. Some kind of "Sales" stuff maybe, who knows?
Meanwhile you can install it and see if it holds 20 amps steady when set at 14.7v. If it does, you are good. If not, you will have to use fatter input wiring or use the frame until it holds its 20a.
Also when they specify the output wiring they seem to forget that the batteries also have some resistance, not just the wiring. So you might have too much voltage drop between Renogy output and battery post voltage when you measure each in real life. IMO use your #8 for the output and #4 for the input and hope for the best.
You won't really know until you install it and try it out. Measure everything and be ready to adjust the installation as required.
Yes but what is that rating based on? 20 amps output means 250/20 = 12.5 volts.
You can choose a charging profile that is 14.7v at 20 amps = 294w.
That is what it is supposed to do, never mind its "rating" of 250w. I have no idea why they have that in their specs. It is like those converters that are "rated" for when they are at 13.6v and not when they are at 14.4v. Some kind of "Sales" stuff maybe, who knows?
Meanwhile you can install it and see if it holds 20 amps steady when set at 14.7v. If it does, you are good. If not, you will have to use fatter input wiring or use the frame until it holds its 20a.
Also when they specify the output wiring they seem to forget that the batteries also have some resistance, not just the wiring. So you might have too much voltage drop between Renogy output and battery post voltage when you measure each in real life. IMO use your #8 for the output and #4 for the input and hope for the best.
You won't really know until you install it and try it out. Measure everything and be ready to adjust the installation as required.
