Battery to Charger Size

[ktnissen]

Current system is: 1150 Watts of Solar on the roof, Victron MPPT controller, Victron monitor, 4 x 100 AH Viper Lithium Batteries, Progressive Dynamics PD9160ALV Converter Charger rated at 60 Amp.

When running the generator to help the batteries on bad days I feel that the charging effort is lacking only recording around 30 Amps on average. Can I go for a bigger charger? How big of charger would work with the batteries.

And yes we are power hogs, I bought the Toyhauler with a residential fridge so I can have ice and we put an apartment size freezer in the garage to keep our fish and caribou frozen.

[jkwilson]

You can’t push current into a load without raising the voltage. Your 60A converter isn’t seeing sufficient load to output more than 30A. A 100A converter would also output 30A to the same setup.

[huntindog]

Current system is: 1150 Watts of Solar on the roof, Victron MPPT controller, Victron monitor, 4 x 100 AH Viper Lithium Batteries, Progressive Dynamics PD9160ALV Converter Charger rated at 60 Amp.

When running the generator to help the batteries on bad days I feel that the charging effort is lacking only recording around 30 Amps on average. Can I go for a bigger charger? How big of charger would work with the batteries.

And yes we are power hogs, I bought the Toyhauler with a residential fridge so I can have ice and we put an apartment size freezer in the garage to keep our fish and caribou frozen.

Is your monitor a shunt for the batteries?
If so, it will show the net current going into the batteries. IOW, if your loads total 30 amps, and you are seeing 30 amps to the batteries, then the converter is producing 60 amps. If the solar is producing at the same time, you would need to figure that into the calculations.

[ktnissen]

You can’t push current into a load without raising the voltage. Your 60A converter isn’t seeing sufficient load to output more than 30A. A 100A converter would also output 30A to the same setup.

What would you suggest? I am going to look and see if I can move it closer and increase cable size. The current run is around 4-5 foot using GD supplied cable.

[ktnissen]

Is your monitor a shunt for the batteries?
If so, it will show the net current going into the batteries. IOW, if your loads total 30 amps, and you are seeing 30 amps to the batteries, then the converter is producing 60 amps. If the solar is producing at the same time, you would need to figure that into the calculations.

It is the Victron shunt that is showing, at max, 30ish amp. I don't have issues with the solar and usually the batteries are 100% by mid afternoon. Issue is bad weather days, I can only go two days max and that is if I turn off the ice maker. Running the generator only replacing 30 amps and hour takes a long time. What would be your suggestion?

[jkwilson]

As the battery charges, the rate it draws current from the charger decreases. You can’t force it to take more.

[ktnissen]

As the battery charges, the rate it draws current from the charger decreases. You can’t force it to take more.

This makes sense but, if I am doing good on solar, around 40 amps showing being charged, I turn on the generator it will show in mid 60's AH charging. The batteries are obviously about to take more than the 30 than my 60 amp converter/charger is putting in.

The batteries show a max of 100 AH being charge rate. How do I get that?

[huntindog]

It is the Victron shunt that is showing, at max, 30ish amp. I don't have issues with the solar and usually the batteries are 100% by mid afternoon. Issue is bad weather days, I can only go two days max and that is if I turn off the ice maker. Running the generator only replacing 30 amps and hour takes a long time. What would be your suggestion?

I have a PD 9180ALV With the stock GD 6 ga wire. I have seen in the low 50s. From quite a bit of observing, I am confident that it is putting out 80 amps. The rest is coach loads.
If you install a 100 amp converter you will need to upgrade the wiring. Such an upgrade should net you 70 amps easy to the batteries under the same conditions.
With 4 batteries that are capable of taking 100 amps each, installed using a buss bar, you could feed the batteries 400 amps. You would need to ensure that the wiring could support that, and that you have a bussbar. Simply daisy chaining them will limit the charge to what a single battery can take,,,100 amps. At 400 amps the genset would need to supply 5600 watts on top of it's other coach loads

[huntindog]

As the battery charges, the rate it draws current from the charger decreases. You can’t force it to take more.

He has lithium batteries. not lead acid. He can charge them a LOT faster with the right setup.

[jkwilson]

He has lithium batteries. not lead acid. He can charge them a LOT faster with the right setup.

Lithiums also draw less current as they charge. You cannot make them take more current at a particular state of charge without applying more voltage regardless of the capacity of the charging system.