using a generator to go around the utility input on a hybrid inverter/charger

[mesquito_creek]

That sounds nice and when the day comes I settle down to a small remote cabin that's about the size of system I would like. ?

Its working pretty well and I should have noted its a stationary RV that doesn't move and a ground mount PV array

 

[Hedges]

AC output rectified and fed to MPPT input... Is that the same thing as saying an AC to DC converter?

Are you suggesting that the MPPT charger method of AC output rectified would be more efficient then my standard AC to DC 48v bench charger on the bus bar?

Many battery charges aren't so efficient, while PV chargers are optimized for efficiency.

AC to DC converter is often a regulated switching power supply (which still has poor power factor, ugly harmonics.) Simple rectifier to capacitor is also ugly. I would want to add some kind of soft-start in series to avoid surge charging capacitors in MPPT.

My main objective was to access all battery charge and measurement functions of the inverter/charger, rather than sneaking around it with a separate battery charger. In the case of my Sunny Island, would require a shunt to it can see who else is charging how much. If I fed a generator into an AC coupled PV inverter, for all it knows this is another PV source.

With an inverter generator, tapping off the DC rail seems like the thing to do. It is likely charged by a 3-phase generator, less ripple.

 

[noenegdod]

You are correct, except when I want to do this my load is over 1600w and has 2 motor (AC and Fridge) that the spike will even exceed 2000w peak.

The whole 10amp charging deal was to try to eliminate that part of the load to keep me under 1600w.

A soft start on the AC might also help. But at this point I am going to just keep adding more PV and batteries until none of this matters. But I am not doing that in the middle of the summer. Hopefully, just connecting the generator with a standard charger to the battery buss can get me thought the few days this summer I need it.

Ok, so the limit we are discussing is just charging, the load is added on top of that?

The victron multiplus sets an AC limit that prevents over drawing the source. It will draw to the limit and then "assist" the AC input beyond that. That is what I was assuming the limit was referring to.

 

[mesquito_creek]

Many battery charges aren't so efficient, while PV chargers are optimized for efficiency.

AC to DC converter is often a regulated switching power supply (which still has poor power factor, ugly harmonics.) Simple rectifier to capacitor is also ugly. I would want to add some kind of soft-start in series to avoid surge charging capacitors in MPPT.

My main objective was to access all battery charge and measurement functions of the inverter/charger, rather than sneaking around it with a separate battery charger. In the case of my Sunny Island, would require a shunt to it can see who else is charging how much. If I fed a generator into an AC coupled PV inverter, for all it knows this is another PV source.

With an inverter generator, tapping off the DC rail seems like the thing to do. It is likely charged by a 3-phase generator, less ripple.

Very cool... a bit over my capabilities at the moment, but it does make great idea!

While I am very happy so far with mpp hybrid inverter chargers and for the price I can't complain... But if they would just separate out the utility mode charging from the utility mode load/bypass this would all be moot.

I actually have another large 6300 coleman construction generator with a 240 outlet that I could properly hook up L1/L2 without a jumper etc.. But its loud and uses way more fuel. I am also scared of the quality of power it produces to connect it to the inverter. MPP support said I could give it a try.

Here is what they said about hook up the old 6300 square wave generator:
As long as it has a frequency of 58 to 63hz and sometimes putting a small 60W load on it can shape its waveform to be adequate to run the charger.
Set setting 11 or 10 low and work your way up the charging current spectrum

 

[Hedges]

Battery charge powered by generator seems like the way to go. But is there anything in the system that keeps track of battery SoC by monitoring current? Wouldn't want battery charger to bypass it. Also need to ensure battery charger settings are correct for the battery.

Floodlamps directed on your PV panels?

 

[mesquito_creek]

Ok, so the limit we are discussing is just charging, the load is added on top of that?

The victron multiplus sets an AC limit that prevents over drawing the source. It will draw to the limit and then "assist" the AC input beyond that. That is what I was assuming the limit was referring to.

Ok, so the limit we are discussing is just charging, the load is added on top of that?

Yes, unfortunately that is the price I paid for not going with the higher priced and higher quality units like the Victron. I do not have the ability to configure it for my current equipment inverter generator. Its all or nothing. Either lower the load to match the small generator or get a larger generator.

BUT ... I am going to hook up my generator/bench charger to the bus bar and see if I can squeeze by this summer. I will add more PV this winter.

 

[mesquito_creek]

Battery charge powered by generator seems like the way to go. But is there anything in the system that keeps track of battery SoC by monitoring current? Wouldn't want battery charger to bypass it. Also need to ensure battery charger settings are correct for the battery.

Floodlamps directed on your PV panels?

Yes, I have a Victron shunt and by putting the generator/charger on the busbar, the shunt is between the busbar and the inverter. I also have the mpp wifi watchpower app that is pulling the data real time off the inverter. They never seem to agree on the SOC but I believe I have the correct monitoring that you are referring to.

 

[mesquito_creek]

I am not present on site currently so I can only remote monitor from watchpower.... I am 300 miles away from the bluetooth shunt.

 

[schmism]

you can configure your MPP to not charge the batteries off the utility when utility is available. However if your not going to do utility pass through and not optiong to charge the battery off utility (aka generator) then there is little need to ever configure the MPP to access utility power. (if your off grid)

As for a charger to run off the generator and connect directly to the battery bus you can find a link on in my sig on how to build one. You may want to instead to run that into the SCC input and use the MPP to monitor battery voltage as you dont want the BMS to shut off the battery on high voltage cuttoff as that will disconnect your MPP units.

 

[mesquito_creek]

you can configure your MPP to not charge the batteries off the utility when utility is available. However if your not going to do utility pass through and not optiong to charge the battery off utility (aka generator) then there is little need to ever configure the MPP to access utility power. (if your off grid)

As for a charger to run off the generator and connect directly to the battery bus you can find a link on in my sig on how to build one. You may want to instead to run that into the SCC input and use the MPP to monitor battery voltage as you dont want the BMS to shut off the battery on high voltage cuttoff as that will disconnect your MPP units.

Your use case in your PSU mods thread is pretty much my exact scenario. Since I already have the AIMS 48v 25 amp bench charger and the predator 2000 generator, I am going to just use those to see what it does.

The max the aims charger can do is 57.6v and the battery bms is 58.8 so hopefully it can't ever put in more that it can take.

 

[noenegdod]

Ok, so the limit we are discussing is just charging, the load is added on top of that?

Yes, unfortunately that is the price I paid for not going with the higher priced and higher quality units like the Victron. I do not have the ability to configure it for my current equipment inverter generator. Its all or nothing. Either lower the load to match the small generator or get a larger generator.

BUT ... I am going to hook up my generator/bench charger to the bus bar and see if I can squeeze by this summer. I will add more PV this winter.

Seems like a good work around. You pay an efficiency penalty but who cares, its working for now.

 

[houseofancients]

you can configure your MPP to not charge the batteries off the utility when utility is available. However if your not going to do utility pass through and not optiong to charge the battery off utility (aka generator) then there is little need to ever configure the MPP to access utility power. (if your off grid)

As for a charger to run off the generator and connect directly to the battery bus you can find a link on in my sig on how to build one. You may want to instead to run that into the SCC input and use the MPP to monitor battery voltage as you dont want the BMS to shut off the battery on high voltage cuttoff as that will disconnect your MPP units.

in the app go to parameter -> charging source priority -> solar only.

that will prevent charging from the grid, just running loads from the genny.
also you can set a max charging current
that will limit when charging from solar, but will also prevent overloading if you should deside you want charging from both solar and ac

 

[mesquito_creek]

Just an update to anyone in the same predicament as me with just a little bit under capacity on the highest demand months.... Attaching the Signature solar EG4 48v 25a charger to the bus bar and driving it with a Predator 2000 is doing exactly what I need!... It adds about 1000 watts an hour of charging to the 4000 watt PV input and gives me what I need to run 2 AC and 2 people working with Laptops and extra large monitors. We can pretty much do anything else guilt free like run the TV, power the residential fridge, use the microwave and coffee maker just like being on the grid.

We run 1 AC in the bedroom end of the RV overnight set at 76 degrees and I wake up to about 40% of my battery bank left over in the morning....

I am confident an additional 4000 watts of PV And 2 more 48v 105 ah batteries would take me over the top and electricity would be out of sight and out of mind. But I am going to cover the RV first and see how that effects my demand side of the equation before I scale up....

 

[anadiner]

Thank you, that is exactly how I believe I need it to behave. The mpp inverter can deliver the spike load as the AC cycles on and off, the Generator alone can not. When the AC and a fridge is running I am using about 1500-1900 watts. The small generator can not get past the point that the mpp inverter utility input trys to switch everything to the Utility bypass. the Generator trys with 3-4 motor surges and then throws the breaker. With combined input of the battery bank and generator the inverter will just see it all as battery mode. As AC/Fridge cycling I am hoping I can tread water on the battery bank when I am a bit under storage and no PV to keep things alive.

Yikes a/c and frig 1500-1900. Gotta be startup. Although modern frigs r setup to (forgot term) use less during cycling. A/c is different = thorn.

Ive tried leaving a/c on high etc.. but only answer was switching to a mini-split.

Btw, Im currently using a generator during the day. Looked for what u want too, inverter restrictions just became such a hassle that I returned hybrid inverter.

Decided go complete off-grid.

 

[Sasteve49]

LV6048 inverter 6000watts. 4-48v lifepo4 103 ah batteries for 412 total Ah of storage. I have 4000w of PV which is the max on one of the built in mppts. I have another mppt controllers to add another 4K PV

It running a 50amp style RV off grid. One AC unit and the other misc load runs about 1500 ish watts. 2 ACs and other stuff runs about 3000-3200 watts. I see about 3000-3500 watts of PV input for 3-4 hours and can easily run everything (2ac, fridge etc.).

For example it is 9:52 am and I am making about 2438 watts off the PV array right now. I am in southern utah and I make power from about 730 am until about 6pm. Obviously over a pretty normal curve that maxes out about 3500 under perfect conditions. I am using about 22w (no ac no fridge yet) That early morning PV has my battery bank up to 55.1V 85% soc as we get ready for the heat and everything to turn on in the next couple hours

Sounds like my setup except for the batteries being 200ah.
I have a standalong towbehind solar trailer with a 50amp shoreplug for power to my 35ft 5th wheel trailer.
I can run my rv all day with the 6 200w panels, using a/c sparingly and with ac/dc fridge running.
But I tried running an eco- heater and the inverter shut down.
I want to install an ac input plug on the solar trailer to charge batteries and also to set a solar first/ac second on the MPP inverter.
Can I connect a 30amp plug and cable to this inverter for this purpose?
Thanks in anticipation of your input.
Steve.

 

[mesquito_creek]

Sounds like my setup except for the batteries being 200ah.
I have a standalong towbehind solar trailer with a 50amp shoreplug for power to my 35ft 5th wheel trailer.
I can run my rv all day with the 6 200w panels, using a/c sparingly and with ac/dc fridge running.
But I tried running an eco- heater and the inverter shut down.
I want to install an ac input plug on the solar trailer to charge batteries and also to set a solar first/ac second on the MPP inverter.
Can I connect a 30amp plug and cable to this inverter for this purpose?
Thanks in anticipation of your input.
Steve.

The utility input is rated at 60 amps for the lv6048 so I don’t see why not, but the plug type is irrelevant… it’s a 120v with a jumper or 240v wired l1/l2/n … Will has a video on how to jumper the connection if you only have 120v