Help choosing the right converter/charger?

joem789 wrote:
Thanks for the replies. It so happens, because my old charger had problems charging 4 batteries, I had taken 2 of them off for the time being. So with this new unit, it is charging 2 batteries. So I figured it wouldnt take so darn long. It ran all day and late last night. But kept blinking rapidly. I think it was putting out a charge. But not as good as I expected. I can't back it up since I don't have the equipment to check. And I suppose i need to get it. But for now, I tried turning on Boost for a few hours. And it remained in that mode. We also had some sun today, so the solar charger was likely working as well. After the few hours I dropped it back to Auto. So I really have no idea how much charging this new unit does. It seems kinda odd to me that the batteries would be that low considering they have been running everything pretty well up to this point.

I think you really need to have some better instrumentation to figure out what's going on than just the blinking light (which is useful, as far as it goes, but that's only to indicate what voltage setpoint the converter is using or--if AC power is disconnected--it would use if it had power).

Generally, at least if put there with the control button, the charge wizard will stay in boost mode (solid, 14.4V setpoint) for a few hours and then switch to normal mode (blinking, 13.x volts) for about a day, and then change to float mode (13.2V, slow flash once every couple seconds) indefinitely with a brief daily spike back to boost mode to keep the electrolyte in the battery from stratifying. It will also "downshift" if the system voltage drops below some trigger voltage.

Measuring the voltage across and current into the battery will tell a whole lot more about whether it's actually charging and give a better clue as to its current state. Simultaneously measuring the voltage at the converter (and seeing if there's any significant difference between it and the battery voltage) will help indicate whether the converter is working as designed--that is, if the setpoint voltages are what they ought to be--and whether any slow charging is due to undersized wiring or poor connections between the converter and the battery.