Off grid, running generator to charge batteries

Did you measure 14.4 volts out of the converter and then measure 14.4 volts on the battery terminals?

And yes if you wait for the battery to reach 50 percent you will get more amps in. By the time you wait for half charged the sun could peek out and get you back charging with no generator.

Sandia Man wrote:
Your batteries were nearly 90%, that is what most are trying to achieve when using their genny to restore consumed amphours. .

Good point.

Trying to get that last 10%-15% to achieve a fully charged battery can take quite some time, which is why most will deplete their battery bank further before using their generator. Your batteries were nearly 90%, that is what most are trying to achieve when using their genny to restore consumed amphours. Running genny beyond that for just battery charging is, as you have indicated, somewhat fruitless. We have solar as well, but mother nature isn't always so accommodating when we RV off the power grid. On decent weather days we can run genny for about an hour in the morning to power our high current draw items and let solar complete the charging throughout the day.

It takes me about 12 hours of charging using my PD9260C 60AMP charger starting at the 50% charge state to get to the 100% state of charge...

Takes just a tab over three hours to charge my 50% state of charge battery bank to get to the 90% charge state...

Sounds like you are going to see this as well in your setup...

When I am camping off grid I most often run my batteries down to the 50% charge over night where we like to draw some 25AMPS DC current from 6PM to 11PM running my Ham Radio and Mommabear watching HDTV etc... This runs me down to 12.0VDC by 8AM the next morning when I am allowed to run my generator using my PD9260C Charger to get may batteries back up to the 90% charge state. Then I can do this all over again the next day/night run off my batteries.

I can usually do this 50% to 90% charge cycles around 10-12 times before I have to run a full 100% charge to keep seeing the same performance of my battery bank... 10-days camping is usually about our average length of camping off grid so I wait until I get back home to run my battery charger for 12 hours or so to get everything back up to the 100% state of charge... My generator will only run about 7-8 hours on a tank of gas so like to do the longer 12 hour charging run when on shore power...

I don't know what you are expecting your batteries to do in a short charging time of an hour or so of charging... My charging follows the book pretty close of two hours of 14.4VDC then it drops to 13.6VDC for another hour to get to the 90% charge state or stays running at 13.6VDC or 13.2VDC for an additional 8 to 9 hours more to get to the 100% charge state...

I cannot do the one or two hours of charging here and there to keep the good battery performance going... Its starts getting to the 12.0VDC level quicker and quicker if I keep doing this every day...

This is what I see happening when I am charging my battery bank at any rate...

I did this using three GP24 12V 85AH Interstate Batteries in parallel from 2009 to just last season where I finally could not get them to hold up over night any longer.

Working on new battery bank as we speak...

Roy ken

I'm not understanding why you weren't getting 45 amps of charging instead of 15. 87% charge should be Bulk, kinda sounds like you were approaching Absorb. I don't know what boost mode is.

I don't think anyone gets much charging done in one hour, unless they have a big charger and Li batteries.

Disclaimer: I do not own a truck camper.