Lazy Daze Owners' Group

Battery Voltages

August 07, 2014, 03:29:23 pm

Yahoo Message Number: 147849

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Until now, the only way that we had to monitor our batteries was the voltage on the solar controller.  We have a table that says 12.6+ was fully charged.  Now that the battery monitor provides more information, I want to be sure that I am interpreting it correctly.

We would like to watch the percent charged to be sure that we don't drain the batteries too much.  I can tell the monitor that the batteries are fully charged and the monitor can track the outflow.  However, I need to be sure that the batteries are really fully charged to start.

The LD manual indicates that the converter can reach 13.6-13.8 volts.  The solar charger  (HPV-22B) goes to 13.2 volts for shore power and 14.3 for dry camping.  I think that the generator would flow through the converter.  I don't know what the truck alternator can provide.

As a convenience, the battery monitor will also reset to 100% charged when certain conditions are met: 13.2 volts charging current of less than 4% of capacity (9 amps) these conditions hold for at least 3 minutes

All three of these parameters are adjustable.

Admittedly, I think more in terms of 120 volt circuits, but 9 amps seems like a lot of charging is still going on.

For those of you with battery experience, what voltages and current flows do you typically see when your batteries are fully charged?

I am particularly concerned that in a shaded or low-light situation, the solar charger might produce a low current that would falsely appear to indicate that the battery is fully charged.  Does that seem like a valid concern?

Thanks,

Cliff

Re: Battery Voltages

Reply #2 – August 08, 2014, 11:15:14 am

Yahoo Message Number: 147859

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I can set the threshold voltage to an impossibly high value (say 20V) and thus disable the automatic reset.  I can't find any simple on/off option.

Doing that, I must, initially at least, tell the monitor when the batteries are fully charged.  With no charging going on, what voltage should I use as my criterion?