Generator Charging Question

[kayakist]

Currently dry camping and have monitored charging through a Victron BMV-712 battery monitor. I have an Onan 5500 watt generator.


Noticed upon startup that monitor shows about 13.20 amps going in and then amps slowly decrease over time. After an hour and a half amp input is at 7.13 amps.



My confusion is that the generator is rated to put out 46 amps. So I have two questions.


1. Is the total number of amps going into the battery 13.20 down to 7.13 normal?


2. Where are the other 30 or so amps being put out by the generator going?


I'm a newbie at this and appreciate any advice.

[Phreak480]

Originally Posted by kayakist

Currently dry camping and have monitored charging through a Victron BMV-712 battery monitor. I have an Onan 5500 watt generator.


Noticed upon startup that monitor shows about 13.20 amps going in and then amps slowly decrease over time. After an hour and a half amp input is at 7.13 amps.



My confusion is that the generator is rated to put out 46 amps. So I have two questions.


1. Is the total number of amps going into the battery 13.20 down to 7.13 normal?


2. Where are the other 30 or so amps being put out by the generator going?


I'm a newbie at this and appreciate any advice.

Generator output rating is for 120V AC power. That then gets inputted to the RV and feeds the power converter. The power converter is what charges the battery. You need to look at the charge rating of the power converter to determine the max charge rate. Also if it is set up for charging lead acid batteries the charge rate will reduce as voltage goes up.

[kayakist]

Now that makes perfect sense. I've learned something new today. Thank you for the quick and accurate information.

Originally Posted by Phreak480

Generator output rating is for 120V AC power. That then gets inputted to the RV and feeds the power converter. The power converter is what charges the battery. You need to look at the charge rating of the power converter to determine the max charge rate. Also if it is set up for charging lead acid batteries the charge rate will reduce as voltage goes up.

[Aussieguy]

that's normal ...

Battery charger reduces the amps so battery will not boil
each type of batter has a preference on how fast and the voltage it will charge at.
Make sure IF you change your battery you check that your charger can handle it.

---------------------------------

the rest of the amps is sitting around in armchairs waiting for you to turn something on.
turn on the a/c, water heater using electric , converter charging batteries , hair dryer on full blast and then someone wants to use the Kureg!


Pop goes the main breaker... or generator does a mickey flip


when you are plugged in to shore power or generator
they are capable of supplying x amount of current through the wires ...



If you exceed the wire's amp rating then the breaker will trip. It's designed so the wire don't get hot , melts and or starts a fire!

[CHICKDOE]

As stated the converter has a rating for the maximum number of amps it can push into a battery but it rarely gets to this max as the battery itself will limit the number of amps it will accept. The more fully charged it is the fewer amps it will accept.

The 13 amps you mention on the battery monitor are dc amps at 12 volts, about 156 watts. Assuming no loss within the converter it only need to draw 1.3 ac amps at 120, for the same 156 watts.

Your generator has a max rating of 5500 watts which is about 46 amps at 120 volts. Do your converter is putting a very minimal load on the generator, assuming no other loads. Your generator is basically running at idle and producing just over an amp.

As for where all the other amps are, they aren’t there. The generator will not produce more amps than are needed to power the load it sees. As the load increases the generator will produce more amps to support the increased load, up to the limit of the generator, which is limited by its circuit breakers. They are probably 30 amps on one leg and 30 on the other.