PD 4655 - How long to Float Voltage?

[Alphonse]

Installed a PD 4655 converter upgrade and two new SRM24 Interstate batteries. I fully charged the batteries before I installed them.

When I energize the converter with shore power, I get the fast blinking light indicating they are at 90% or greater charge and are charging at 13.6 volts. I confirmed the voltage is in that range.

How long will it take the charging system to switch to float/maintenance voltage (13.2 volts)? It is a function of time? If so, does unplugging shore power reset the time/duration?

[idroba]

It often takes 24 to 48 hours to reach the float voltage stage, and that assumes good batteries with very little internal leakage and nothing else on in the trailer. And I mean nothing.

I believe that the float voltage is only switched on (the 13.2 volts) when the current level drops to a very small amount, like 40 mA or so. I am not sure of the exact number though. I just went through it with my Argosy (two golf cart batteries in series) and it had not dropped to float at 60 mA but a day later it had gone into the float mode and my meter showed no reading at all, so it was under 10 mA.

[68 Overlander]

It is time and voltage based. 30 hours of no voltage demand it will switch to the storage mode and only return to normal mode if there is voltage change (.3 volts) Turning on one light may or may not reset the timer. Several lights would or turning on the water pump for example. The LP and CO detectors normally don't prevent the unit from changing either way. Also, the dusulfation cycle only works in the storage/float mode, every 21 hours for 15 minutes.

[idroba]

Randy has a much better answer than mine.

[Alphonse]

Originally Posted by 68 Overlander

It is time and voltage based. 30 hours of no voltage demand it will switch to the storage mode and only return to normal mode if there is voltage change (.3 volts) Turning on one light may or may not reset the timer. Several lights would or turning on the water pump for example. The LP and CO detectors normally don't prevent the unit from changing either way. Also, the dusulfation cycle only works in the storage/float mode, every 21 hours for 15 minutes.

Thanks for the clarification Randy.

[Alphonse]

Went by and checked mine at the garage and it was on Float. It had been on the clock for two days.

[68 Overlander]

Perfect, it probably dropped at 30 hours but you weren't there to see it.