How Does a Converter Hold its Voltage?

Hi DrewE,

Make that 15 minutes of 14.4 every 22 hours. It is equalization only in the sense that it "stirs" the electrolyte.

DrewE wrote:
My PD will cycle between three different setpoint voltages, including several minutes of higher voltage (14.4V) every several hours when it's in float mode (13.2V), which they stretch the truth to call equalization.

From too much experience, I can safety state that no large cheap power supply I have seen will maintain rock solid voltage regulation from no load to full load.

The best of my bunch is a Lamda which within range varies an astounding .02 within a wide input and output range. It's cost induces sticker-shock.

Meanwell and Megawatt all droop .2 to .3 volts open/circuit vs a 2 amp load. My Chinese bench 0-60vdc 10 amp power supply droops to the hundredths of of volt.

Thanks. So my converter voltage is steady as a rock based on observation when it is not connected to a battery. The battery has a draw on it.

So connect, the battery's loaded voltage rises to meet the converter's voltage so now the converter is carrying the load. Except for the wiring loss (not much at low amps, but some)--I could have that wrong as to what really happens there...

Perhaps my question is: Once the two voltages are equal except for wiring loss, and there is no amps to the battery, just to the load, how far down would the battery voltage get before it started to get amps from the converter again?

During that time, would you see negative amps on the Trimetric, even though the battery voltage is still as set (to one decimal place) ?

I think most converters these days are basically voltage regulated switching power supplies. The regulation may not be absolutely perfect with changing loading, but it should be pretty close until you start to run into current limiting or power limiting and the voltage sags. Line to load regulation should be very good, a feature inherent with switching power supplies in general. The regulation would be of the voltage at the converter output, not at the battery, unless you have some setup with remote voltage sense lines and I haven't run across a converter that supports that.

This is, of course, separate from any higher-level charge algorithm that's changing the voltage setpoint. My PD will cycle between three different setpoint voltages, including several minutes of higher voltage (14.4V) every several hours when it's in float mode (13.2V), which they stretch the truth to call equalization. Other makers have different algorithms, but will cycle between stages according to some program.

If you have some wiring impedance, it's possible that the battery floating at the converter's float voltage could discharge a bit and later charge a bit as the overall 12V load changes, due to the relative impedance between the load and the two voltage supplies. That's not something to worry about in itself IMHO (well, aside from wanting to have good low-impedance connections).