MPP LV6548 Feature... Requests?

Lt.Dan

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Hey guys, I've had my 2x LV6548's for a while now in my trailer, and I have some issues with it that I believe could be solved with a firmware update. The reason I'm posting here is I dont know if its possible and is limited in hardware capability, or if its just software.

Now, I've been to a few RV parks since installing this system, and both of them had shoddy wiring, and 1 of them only had a 30 amp connections. At both places I had problems popping breakers both inside the trailer, and also at the pole. The RV park that had the 30 amp connector had voltage dipping below 110v very often and I saw it as low as 103v a few times when the breaker popped. I also was forced to switch the LV units to single phase because there was only single phase coming in, but thats not something that can be fixed with software and is irrelevant for what I'm trying to do. I even had my 50a to 30a adapter melt a pin on the 30a side!

Charging the batteries while in "Bypass mode" is also counterproductive because I can't overload the breaker in the pole. So for instance, if I am limited at 3600 watts (120v X 30a, even though getting down to 103v x 30a is only 3090w) then I set the chargers on the LV unit to charge at 50a (51.2v X 50a = 2560w), then I turn on some lights, the TV, a fan, the refrigerator, I pop the breaker because the charger is constantly going to draw that 50a no matter what. This could be solved with a "Max Amperage Draw from AC" option. I know Victron equipment has this option already, dont patronize me! Lol. But if I could set a max of 25a from the AC Input, then charge at max, it would be a big plus.

Another fix for this situation is, right now I cant set the inverter to charge the batteries while inverting. It will only charge via AC input while in "Bypass mode" which means the trailer is powered from the AC input at the same time it is charging. I'm curious if I (MPP Solar) could somehow program the inverters to take in power from the pole, strictly to charge the batteries, then had the inverter side supply power to the trailer. This always puts constant 119-120v to the whole trailer, and not a wildly horrible voltage curve. Then I can set it to charge at 60a (51.2v x 60a = 3072w) and never overload the breaker at the pole.

Can this happen? If so, I'm going to try and contact MPP and see if they can implement a firmware update with these features.
 

Sanwizard

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Feb 2, 2021
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Hey guys, I've had my 2x LV6548's for a while now in my trailer, and I have some issues with it that I believe could be solved with a firmware update. The reason I'm posting here is I dont know if its possible and is limited in hardware capability, or if its just software.

Now, I've been to a few RV parks since installing this system, and both of them had shoddy wiring, and 1 of them only had a 30 amp connections. At both places I had problems popping breakers both inside the trailer, and also at the pole. The RV park that had the 30 amp connector had voltage dipping below 110v very often and I saw it as low as 103v a few times when the breaker popped. I also was forced to switch the LV units to single phase because there was only single phase coming in, but thats not something that can be fixed with software and is irrelevant for what I'm trying to do. I even had my 50a to 30a adapter melt a pin on the 30a side!

Charging the batteries while in "Bypass mode" is also counterproductive because I can't overload the breaker in the pole. So for instance, if I am limited at 3600 watts (120v X 30a, even though getting down to 103v x 30a is only 3090w) then I set the chargers on the LV unit to charge at 50a (51.2v X 50a = 2560w), then I turn on some lights, the TV, a fan, the refrigerator, I pop the breaker because the charger is constantly going to draw that 50a no matter what. This could be solved with a "Max Amperage Draw from AC" option. I know Victron equipment has this option already, dont patronize me! Lol. But if I could set a max of 25a from the AC Input, then charge at max, it would be a big plus.

Another fix for this situation is, right now I cant set the inverter to charge the batteries while inverting. It will only charge via AC input while in "Bypass mode" which means the trailer is powered from the AC input at the same time it is charging. I'm curious if I (MPP Solar) could somehow program the inverters to take in power from the pole, strictly to charge the batteries, then had the inverter side supply power to the trailer. This always puts constant 119-120v to the whole trailer, and not a wildly horrible voltage curve. Then I can set it to charge at 60a (51.2v x 60a = 3072w) and never overload the breaker at the pole.

Can this happen? If so, I'm going to try and contact MPP and see if they can implement a firmware update with these features.
Menu setting 11 has max ac charge current. Perhaps review all your current settings with the manual first.

Maximum utility charging current Note: If setting value in program 02 is smaller than that in program in 11, the inverter will apply charging current from program 02 for utility charger. 30A (default) Setting range is 2A, then from 10A to 120A. Increment of each click is 10A.
 

Lt.Dan

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Menu setting 11 has max ac charge current. Perhaps review all your current settings with the manual first.

Maximum utility charging current Note: If setting value in program 02 is smaller than that in program in 11, the inverter will apply charging current from program 02 for utility charger. 30A (default) Setting range is 2A, then from 10A to 120A. Increment of each click is 10A.
Yes I understand that feature, but thats Max AC CHARGE Current. Not Max AC Current. You can set the max charge current to 50a, but then pull way way more power straight to your loads, thus overloading the breaker at the pole.
 

Sanwizard

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Yes I understand that feature, but thats Max AC CHARGE Current. Not Max AC Current. You can set the max charge current to 50a, but then pull way way more power straight to your loads, thus overloading the breaker at the pole.
So just reset setting # 2 to 10amps when your in this situation. You can also set your BMS max charge and discharge current correct?
 

Sanwizard

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So just reset setting # 2 to 10amps when your in this situation. You can also set your BMS max charge and discharge current correct?
Also, perhaps for a mobile solution, many RV parks are not expecting someone with 13KW available in their RV. You are kinda ahead of your time.
 

Lt.Dan

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So just reset setting # 2 to 10amps when your in this situation. You can also set your BMS max charge and discharge current correct?
#2 is also just a max CHARGE current. I dont want to limit my PV charge current too.

The BMS cannot regulate amperage, if I set the BMS to a lower amperage, it will stop charging entirely, not limit it. This also doesn't help the problem if the LV units are charging at 3000 watts and then I turn on the microwave and exceed the 30a - 3600watt max.

I want the inverter to sense the load and vary the charging current to keep the load from the Grid from exceeding 3600 watts. That way if I set the max AC draw to be 3000 watts, and I turn on a load that draws 1500 watts, then the charger will come down to 1500 watts as well, to prevent the LV from tripping the breaker.
Also, perhaps for a mobile solution, many RV parks are not expecting someone with 13KW available in their RV. You are kinda ahead of your time.
In not asking for 13KW from the RV park, but just something to keep my AC units running while its 110* outside and there is no shade.
 

Sanwizard

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#2 is also just a max CHARGE current. I dont want to limit my PV charge current too.

The BMS cannot regulate amperage, if I set the BMS to a lower amperage, it will stop charging entirely, not limit it. This also doesn't help the problem if the LV units are charging at 3000 watts and then I turn on the microwave and exceed the 30a - 3600watt max.

I want the inverter to sense the load and vary the charging current to keep the load from the Grid from exceeding 3600 watts. That way if I set the max AC draw to be 3000 watts, and I turn on a load that draws 1500 watts, then the charger will come down to 1500 watts as well, to prevent the LV from tripping the breaker.

In not asking for 13KW from the RV park, but just something to keep my AC units running while its 110* outside and there is no shade.
Let us know what MPP says. Its an interesting issue.
 

Lt.Dan

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These problems will all be solved if I got a seperate 48v AC charger and just didn't plug the trailer into the grid. But id rather use the 2x chargers I already bought and are installed in my trailer lol
 

Lt.Dan

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I think its a good thing that nobody has jumped in and said its not possible because it would conflict with specific hardware or something. I will be emailing them shortly with questions, but its going to be tough explaining something like that with the language barrier.
 

TinyHouseSolar

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Jun 26, 2021
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Bump as I would also like these updates to be implemented. It seems as though there is an expectation that the grid source will always be equal to or greater than the total load, which is not true in my case. The best way I can describe how I would like it to work is to be able to treat the AC input similar to how it treats the PV input, where if available and needed, it charges the batteries, but if it isn’t needed, it doesn’t. The 6548 seems to be set up in an “all or nothing” way where you can only set one voltage point where it switches from grid to discharge or discharge to grid. Instead it would be nice if it could start bringing in AC power at a voltage point 1-2v higher than the switch to grid threshold. The current could then be set up on a gradient where the closer you get to the switch to grid threshold voltage, the more current (up to a defined limit) is drawn from the AC source.

I agree that the workaround would be to attach a separate 48v charger to the battery bus but it would be cool if it could be triggered on and off at particular voltages. You could have the charger come on when it senses the battery bank is sitting at 40% and switches off when it senses 60%. This would limit the amount of AC power used while also allowing the batteries to always be powering the inverter load, which in my case is ideal because they have 5-6 times more current carrying ability.
 

Sun$

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I thought I read somewhere, maybe it was on one of the European forums, that the invert function and the charge function use the same mosfet transistors in all of these HF inverters and thus can only work in one direction at any given time so you can either invert the DC into AC to power loads or rectify the AC into DC to charge but not both simultaneously.

One of the Spanish or Italian forums had a really good writeup and a teardown of the 8048MAX mpp solar inverter and i think thats where i read about it.
 

Lt.Dan

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I thought I read somewhere, maybe it was on one of the European forums, that the invert function and the charge function use the same mosfet transistors in all of these HF inverters and thus can only work in one direction at any given time so you can either invert the DC into AC to power loads or rectify the AC into DC to charge but not both simultaneously.

One of the Spanish or Italian forums had a really good writeup and a teardown of the 8048MAX mpp solar inverter and i think thats where i read about it.
This is kind of what I figured, cant have power going 2 ways through the same hardware. I gave up trying and just bought a separate charger. I would still like to pick someone at MPP Solars brain about it though.
 

Sun$

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This is kind of what I figured, cant have power going 2 ways through the same hardware. I gave up trying and just bought a separate charger. I would still like to pick someone at MPP Solars brain about it though.
I could be wrong tho. I tried to gain more info/ block diagrams about it but their seems to be alot of changes between the different models. It would seem the models with high voltage pv input also seem to have hardware capabilities for grid feedback which I believe would require the hardware to convert both ways simultaneously.
 
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