Can an inverter / generator (Honda EU200i) be modified to charge batteries directly?

[sunsurfer]

So how will you control engine speed?

I would just have an adjustable throttle. Set it to the minimum opening needed for maxing out the MPPT. You would want to size the MPPT to how many watts you want to run the motor at.

Say its a 2000watt motor. Maybe run it for 800watts output as an example. The Governor will limit max RPM.

 

[sunsurfer]

Does anyone know if inverter gennies have mechanical governors? I know there are servo throttles but is there a max RPM mechanical Gov?

 

[OTRwSolar]

What I was looking at was being able to produce maybe 100A to 120A at 12v nominal to reduce the run time.

For what it's worth, we power our 12v Victron Multiplus II 3000 120a charger with a Honda EU2200 often. If we're willing to run the Honda at its max continuous current rating of 15a (1800w), we can get 105-108a of charge current. I believe the Honda is also rated to produce 18.3a (2200w) for 30 min. On a few occasions we have temporarily pushed the Honda to ~16.8a (~2000w)---which is enough to get 115-118a from the Multiplus. Not bad.

 

[Checkthisout]

I would just have an adjustable throttle. Set it to the minimum opening needed for maxing out the MPPT. You would want to size the MPPT to how many watts you want to run the motor at.

Say its a 2000watt motor. Maybe run it for 800watts output as an example. The Governor will limit max RPM.

How do you plan on getting that to work?

And at the end of the day, why when you can just plug a charger into the Gen, retain all of its useful features and efficiency and be done with it.

 

[Checkthisout]

Does anyone know if inverter gennies have mechanical governors? I know there are servo throttles but is there a max RPM mechanical Gov?

That's not how governors work.

They are redline-protected via spark cancelation.

The electronic throttle controls engine target RPM in relation to the load on the machine. In order to achieve best efficiency, it sets an RPM that loads the engine to about 80% or so.

It's more complex than this and requires capacitors etc to pick up loads without seesawing all over the place.

Why go through bypassing all that and then try some backyard method of gaining a portion of it back?

Any efficiency you think you might gain by not going through the voltage stepping process will be more than offset by having some cheeseball setup that requires manual adjustment of engine speed.

That said, please share your results with us and the fuel savings gained.

 

[hwse]

So how will you control engine speed?


That is the downside of the inverter gen for such a project. You won't have any way to govern engine speed as they lack a mechanical governor.

From what I remember, the Honda inverter generators put out 130 Volts out of the winding. I assume other brands are the same.

That's why the inverter assembly is so compact.

I am pretty sure that they do have a mechanical governor. A DC alternator is not speed dependent so the RPMs only mater as to how much power is porduced. It would only need to make more voltage than my battery bank and use a MPPT charge controller to control the charging voltage.
130vDC is pretty hot so that would mean that rewiring the stator to a lower voltage would more than likely be needed.

 

[hwse]

That's not how governors work.

They are redline-protected via spark cancelation.

The electronic throttle controls engine target RPM in relation to the load on the machine. In order to achieve best efficiency, it sets an RPM that loads the engine to about 80% or so.

It's more complex than this and requires capacitors etc to pick up loads without seesawing all over the place.

Why go through bypassing all that and then try some backyard method of gaining a portion of it back?

Any efficiency you think you might gain by not going through the voltage stepping process will be more than offset by having some cheeseball setup that requires manual adjustment of engine speed.

That said, please share your results with us and the fuel savings gained.

I do not have a Honda. Mine is from Costco. From the way that it runs, It appears to not have a load sensing governor. It has a high-speed setting where the power (throttle) adjusts to maintain rpms at different loads. It also has a low-speed setting. That is how a mechacical governor works.

 

[Checkthisout]

I am pretty sure that they do have a mechanical governor. A DC alternator is not speed dependent so the RPMs only mater as to how much power is porduced. It would only need to make more voltage than my battery bank and use a MPPT charge controller to control the charging voltage.
130vDC is pretty hot so that would mean that rewiring the stator to a lower voltage would more than likely be needed.

The Hondas, Briggs, General, Polaris, Yamaha etc inverter generators DO NOT have a mechanical governor.

So you're going to rewind the stator (a huge undertaking), eliminate the inverter and thus the engine speed control so that you have engine with an alternator on it that outputs dc voltage that kind of matches battery voltage but still must be run through some sort of charging control device.

I just don't see how this provides any benefit at all. Just a lot of time tearing apart something that works to spend money to make it not work very good.

I could be wrong which is why I'm excited to see your end result.

 

[hwse]

For what it's worth, we power our 12v Victron Multiplus II 3000 120a charger with a Honda EU2200 often. If we're willing to run the Honda at its max continuous current rating of 15a (1800w), we can get 105-108a of charge current. I believe the Honda is also rated to produce 18.3a (2200w) for 30 min. On a few occasions we have temporarily pushed the Honda to ~16.8a (~2000w)---which is enough to get 115-118a from the Multiplus. Not bad.

If I had a 300W invertor with 120A charger I would do the same, but I do not have the room in my boat for such a big invertor and have no need for that much AC. My biggest AC load other than my two 30A chargers is the Shark vacuum which runs fine on a 400W modified sine invertor.

 

[Checkthisout]

I do not have a Honda. Mine is from Costco. From the way that it runs, It appears to not have a load sensing governor. It has a high-speed setting where the power (throttle) adjusts to maintain rpms at different loads. It also has a low-speed setting. That is how a mechacical governor works.

No.

It has an economy and high speed setting.

 

[Brucey]

I guess the closest off the shelf unit would be an ecoflow dual fuel generator, which can charge a compatible Delta unit directly via DC using an additional battery port. But I don't believe the BMS/signalling data on the comms pins has been decoded.

 

[sunsurfer]

I have a torn apart Ryobi inv gen I just ran it and got between 150-200vac out of the permanent mag gen head. I have gotten for free. It will be a good test. I will start a build thread once I get my current project done and we will have some fun.

 

[hwse]

No.

It has an economy and high speed setting.

I agree it has a high and low speed setting but would be surprised if it did not have a mechanical governor for that function like every other small Honda Tecumseh, Briggs or Yamaha motor out there.

 

[Checkthisout]

I agree it has a high and low speed setting but would be surprised if it did not have a mechanical governor for that function like every other small Honda Tecumseh, Briggs or Yamaha motor out there.

The generators I mentioned DO NOT have mechanical governors.

That would add needless complexity to the system to have one. It's 100% electronic via the servo in the carburetor. Among other things I work on them for a living and have seen the brands I listed torn apart.

The "High Speed" setting should be thought of as nothing more than raising the engine's minimum set speed. That's all it does.

I don't think its worth it to mess with and ruin all the benefit of an inverter gen by bypassing it's ability to control engine speed based on load.

However, the user who is going to experiment with the trashed Generac..yeah that's worth tinkering with for nothing more than tinkering's sake!?

 

[CoolWill]

I always think of doing wacky things like this. I usually get to the testing stage when I realize that any gain in efficiency is going to be lost in doing the custom work, not to mention that when the modified/specialized thing I've tinkered together dies, it's replacement will need to be modified too.

So, sure, you CAN take the DC from the generator and use it to charge batteries. But wouldn't it be better to just take the hit in efficiency in order to gain drop-in serviceability? If you use a generator to power a charger, then if any component takes a dump, all you have to do is throw it in the ocean and plug another one in. But if your system relies on custom components, you are stuck until you can rig a new thingamajig.

 

[Checkthisout]

I always think of doing wacky things like this. I usually get to the testing stage when I realize that any gain in efficiency is going to be lost in doing the custom work, not to mention that when the modified/specialized thing I've tinkered together dies, it's replacement will need to be modified too.

So, sure, you CAN take the DC from the generator and use it to charge batteries. But wouldn't it be better to just take the hit in efficiency in order to gain drop-in serviceability? If you use a generator to power a charger, then if any component takes a dump, all you have to do is throw it in the ocean and plug another one in. But if your system relies on custom components, you are stuck until you can rig a new thingamajig.

Ha ha.

Together we are the biggest buzz kills on the face of the planet. ?

 

[CoolWill]

Ha ha.

Together we are the biggest buzz kills on the face of the planet. ?

But nobody tries to talk me out of my silly adventures! I only offer sensible advice, never do I take it.

 

[sunsurfer]

But nobody tries to talk me out of my silly adventures! I only offer sensible advice, never do I take it.

You cant replace the experience gained from such tinkering