promatic 30-3 Charger and battery question

[PSNI]

I went to the boat (2000 Sundancer 380....in it's slip, winterized) the other day and found my starboard batteries completely drained and the port batteries showing 7 volts (enough to open the engine hatch).

I made sure the charger was getting AC power and powered it off and on. That seemed to reset it because the starboard battery energized with a very low voltage and the carbon monoxide detector started giving a low voltage alarm. I guess that how the stb batteries got drained (so I disconnected it).

I tried to find a manual for the charger online and instead found recommendations to replace it.

I went to the boat today with my new Promariner 63140 and found both sets of batteries fully charged. I didn't end up replacing the charger (yet) and I'm wondering if this is a sign of it's imminent demise. It was really cold here last week and I wonder if that stopped it from delivering a charge. Has anyone had this experience?

I did find a manual online. It says the unit will turn off if the temperature exceeds 140 degree F. Maybe it's sensitive to cold or sensitive to cold batteries.

I'm now reading that it will also shut down if the voltage goes too high...16.5 volts. Any ideas on what would cause that?

On a related topic, when I look at the 380 wiring diagram, the starter battery does not seem to be connected to the charger. Is that correct? Does that mean I should make sure it's charged over the winter by some other means?

Thanks, Peter

 

[Lazy Daze]

Maybe A/C power was lost for a while/dock breaker tripped/etc? On top of that, maybe a 12V item was left on? That could, at the very least, explain the situation.

Use some 12V items a whole bunch, then turn on the converter and measure the V at the battery banks. See what the voltage is.

In that diagram, you have (3) banks of batteries (port, stbd, genny). All three are being charged by the converter/charger.

 

[PSNI]

Thanks Dennis. I'll do that and make some observations.

Do you know if it's common to not have the starter battery connected to the charger? I guess the whole idea is that the house batteries are the ones that require charging after use and the genny is not connected to the alternator so it needs the charger to keep it topped up.

And one more question. Is the converter function of this device intended to provide DC power when connected to shore power? So even if the batteries were dead, the converter provides DC power to do things like open the engine compartment hatch?

I noticed a couple of weeks ago that the hatch seemed to raise more slowly than usual. I attributed this to loss of battery amperage due to the extreme cold. But if the Promatic is also a converter, it should not have been affected by the cold. Perhaps it had already shut itself down at this point and the hatch was running off batteries that were slowing being drained.

Thanks for answering my newbie questions.

Peter

 

[Lazy Daze]

Peter, the "house batteries", as you're referring to them, are ALSO your starting batteries. Follow the leads from the two main battery banks... to the battery switches... to the emergency start solenoid... to your engines.

The converter "converts" 120V to 12V to charge the batteries. The batteries supply power to your 12V items. If the batteries were dead, it would be trying to charge your batteries at the same time also trying to feed 12V items. If a particular 12V item draws more power (amps) than the converter can supply, then that thing would either work slowly or not at all.

Even fully charged, brand new batteries will lose efficiency in cold weather and not be able to supply as much amperage as quickly, as compared to warm weather. Even electricity, itself, will not travel as efficiently (quickly) through cold wires... in addition, electric motors are made up of hundreds of feet of wires.

How old are your batteries? You could have them load tested for free at auto stores - but they need to be fully charged, first.