I was testing out my 48v Battery charger on 120v outlet from my Rosie and noticed something I couldn't understand. The charger was pulling a few amps, not much else was on so maybe the Rosie was putting 5 amps out.
But thats when I noticed the Rosie was adding power from the battery instead of using all the power from the Grid as it was set to 10 amps, so there was plenty to be pulled. In order to fix that I had to disable Grid Support.
I would expect Grid support to add power from the battery if it was very close to the 10 breaker size set, but not when it was using less than half that could be gotten from the Grid set to a 10 amp setting.
I don't want it to use the battery if all the power can be taken from the Grid based on the setting. And I really don't think I should have to keep going into the MNGP2.
Is it supposed to work like that?
How do I adjust that if it is?
What is the threshold that for using the battery based on the breaker size? 50% doesn't really sound right.
-Bill
Rosie limits AC IN to 75% of the "breaker size" setting + or - 2%
This is to be sure to comply with the NEC 80% rule for continuous circuit limits.
The MNGP2 reads data off the CANBUS so there may be a slight delay on what you see.
In your case you set "breaker size" to 10A so Rosie will use battery to assist probably around 7A and there may be a little swing on the lower settings.
Quote from: bigbillsd on April 18, 2026, 10:51:28 AMI was testing out my 48v Battery charger on 120v outlet from my Rosie and noticed something I couldn't understand. The charger was pulling a few amps, not much else was on so maybe the Rosie was putting 5 amps out.
But thats when I noticed the Rosie was adding power from the battery instead of using all the power from the Grid as it was set to 10 amps, so there was plenty to be pulled. In order to fix that I had to disable Grid Support.
I would expect Grid support to add power from the battery if it was very close to the 10 breaker size set, but not when it was using less than half that could be gotten from the Grid set to a 10 amp setting.
I don't want it to use the battery if all the power can be taken from the Grid based on the setting. And I really don't think I should have to keep going into the MNGP2.
Is it supposed to work like that?
How do I adjust that if it is?
What is the threshold that for using the battery based on the breaker size? 50% doesn't really sound right.
-Bill
What is your grid support percentage set to? If the battery soc is above that threshold it will invert from battery. Will only add additional support from grid once you exceed Rosie rating (upto 60A max). Once soc drops below your threshold then it will switch to grid pass thru mode, no inverting.
Quote from: Brucey on April 18, 2026, 09:48:03 PMWhat is your grid support percentage set to? If the battery soc is above that threshold it will invert from battery. Will only add additional support from grid once you exceed Rosie rating (upto 60A max). Once soc drops below your threshold then it will switch to grid pass thru mode, no inverting.
Not sure what that is. I will look that up when I get back into the coach. (where is the remote access feature?) I'm not really grokking how that works. I always want to use the grid if I have it up to the max breaker size I have set. This is a mobile version of the Rosie, being in an RV probably hooked up to Shore Power I always want to use the Shore power up to the breaker size I have set. I would never want it to pull from the battery when its not needed.
But If I turn on the AC and it needs 25 amps and my breaker is set to 20 I want the AC to run and get the rest from the battery. But I don't want to on a 30 amp breaker and run the AC and have it take anything from the battery it wouldn't be helpful to deplete the batter when that's not needed.
I am wondering if they didn't think folks would be using these in an RV even though I have the mobile version?
I am guessing there is a setting to have it work correctly for RV use? Only use the battery when required to do so.
nd
Quote from: Wizbandit on April 18, 2026, 06:57:40 PMRosie limits AC IN to 75% of the "breaker size" setting + or - 2% This is to be sure to comply with the NEC 80% rule for continuous circuit limits. The MNGP2 reads data off the CANBUS so there may be a slight delay on what you see. In your case you set "breaker size" to 10A so Rosie will use battery to assist probably around 7A and there may be a little swing on the lower settings.
Let me ask these questions to see I am understanding what you are saying.
Breaker set to 10 amp. No power would be taken from battery unless its pulling 7.5amps or greater?
If I wanted to allow 10 amps to be drawn from the grid, then 13.33 amps would be the breaker setting?
From what I can see I would not know the battery is being drawn down unless I am down in my inverter bay with the MNGP2? Solar Assistant doesn't provide that from what I can tell.
Hmm..
Quote from: bigbillsd on April 19, 2026, 12:16:20 AMQuote from: Brucey on April 18, 2026, 09:48:03 PMWhat is your grid support percentage set to? If the battery soc is above that threshold it will invert from battery. Will only add additional support from grid once you exceed Rosie rating (upto 60A max). Once soc drops below your threshold then it will switch to grid pass thru mode, no inverting.
Not sure what that is. I will look that up when I get back into the coach. (where is the remote access feature?) I'm not really grokking how that works. I always want to use the grid if I have it up to the max breaker size I have set. This is a mobile version of the Rosie, being in an RV probably hooked up to Shore Power I always want to use the Shore power up to the breaker size I have set. I would never want it to pull from the battery when its not needed.
But If I turn on the AC and it needs 25 amps and my breaker is set to 20 I want the AC to run and get the rest from the battery. But I don't want to on a 30 amp breaker and run the AC and have it take anything from the battery it wouldn't be helpful to deplete the batter when that's not needed.
I am wondering if they didn't think folks would be using these in an RV even though I have the mobile version?
I am guessing there is a setting to have it work correctly for RV use? Only use the battery when required to do so.
So if you want it to prioritize grid then turn off grid support. That's designed to maximize your solar utilization.
Use Load Xfer mode. That should supplement limited ac input with inverter power as needed.
Its another $207 but potentially could add a second mngp2 to have upstairs so you dont have to dive in to the basement all the time. Or just move your current mngp2 upstairs.
Quote from: Brucey on April 19, 2026, 10:35:14 AMIts another $207 but potentially could add a second mngp2 to have upstairs so you dont have to dive in to the basement all the time. Or just move your current mngp2 upstairs.
I just purchased a second one, even then, having to fiddle with it often seems a bit odd. And getting the wire up to the cabinet I want to put it to replace the Magnum Remote will not be fun.
Essentially the "Only" thing you should need to fiddle with is the AC BREAKER SIZE in the AC Input menu as you change where you are plugged in. As Jim pointed out the Rosie will limit that to about 75% but you stated 120V in so that adds a level of information to it. Remember Rosie is split phase and each phase does its thing so if you had breaker size set to 10A and L1 is drawing 7A AC it should be teetering on the edge of using some battery. But keep in mind if L1 and L2 are doing 5A AC that is really 10A AC o L1 if you have 120 only coming in. My suggestion is if you are going to plug into 120 you use a dogbone adapter from 50Amps to 30Amps and another to 20A this will apply 120V to L1 and L2 then it will behave more like you anticipate
Quote from: FNG on April 21, 2026, 07:00:08 AMMy suggestion is if you are going to plug into 120 you use a dogbone adapter from 50Amps to 30Amps and another to 20A this will apply 120V to L1 and L2 then it will behave more like you anticipate
That was how I was testing it. Using a standard Dogbone as a Y adapter feeding both L1 & L2. I have made a special adapter that will only feed 120v to L1. No L2 so the Rosie can still make 240v when needed. I probably wouldn't need that adapter till I can afford that Wolf Induction Cooktop of my wifes dreams...