Growatt 24V vs. MPP LV2424 - HowLoud?

Eaks77

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Jul 19, 2021
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First, my apologies, I know there's a couple threads surrounding this topic, but I'm still unable to find the answers I'm looking for.

I have a shed I'm converting into an office and want to power it off grid, with a AC input for charging batteries
The plan:
- 24V 310AH LifeP04 - Homebuilt - I'll probably have questions about BMS's in the future
- 4x 405W-445W Bifacial panels on a pergola
- And either a Growatt 24V 3000W or MPP LV 2424 MSD... and this is where I have questions...

Questions:
- Which one is better? haha, ok, maybe that isn't as straight forward, so I'll break it down into specific questions
- I've heard that both the MPP and Growatt units are noisy. I've read that while they're very similar, the Growatt might be a little quieter. This unit will be in a 8x12' shed/office, where I plan to be working (desk/computer work). How much am I going to be bothered and which one is actually quieter? I was thinking about placing the unit into the sheds attic, but they're not rated for Canadian winters.
- The MPP is rated for 2400W and the Growatt is 3000W. As of now, the plan is to feed the AC power from either one of these inverters into a subpanel where there are 6 circuits on 15amp breakers. The two hot lugs will be bridged, because neither of these inverters are individually split phase . Based on that, from what an electrician told me, I realistically won't be able to draw more than 1500W total. True? I thought the math was 1800W. If so, then there's no point in upgrading to a 3000W output, correct? I feel like I'm missing something here.? In the shed, i'll probably have 1-2 desktop computers running, with <30W of lights.. but in the winter I plan to run a small crypto mining rig for heat, or find a smaller <750W heater.
- Are there any other all-in-one units I should consider? What's the deal with amazon's PowMR? Worth considering?
- Are there any 24v units with split phase in a single unit? Is that even possible? I've seen a couple 48V's.
- What are the actual differences between LV2424 - LV2424 Hybrid - LV2424 MSD?
 

derekisastro

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Jan 27, 2021
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I cannot comment on all of your questions, though I do have the 24v Growatt 3000W device. It is noisy. From what I've read, they're all noisy ... is one going to be less noisy than the other ... maybe? Will that difference be enough that it makes a difference to the ambient sound in an office? I doubt it. I'm in the process of trying to work out the best way for me to reduce the noise ... either soundproofing a cabinet/closet around the device (I have concerns of overheating) or moving the device into another are and just running more wire (i have concerns about the costs of the wire and running the longer wires) ...

I do not understand the electricians' comments about 1500W, nor your own about 1800 W. If it's a 300w/2400w device if you run it on a panel that you are wiring for only 120V ... you're still going to be able to pull the 3000W/2400W from the panel ... it pretty much just acts like a big busbar at that point. I could see you could argue/say that you can only pull 1500W from each 'side/phase' inside the panel but again, that would still mean a total of 3000W. Just make sure you clearly mark the panel as "120V ONLY" and that you don't ever use multi-pole breakers or run multi-branch circuits in it.

As for what other all-in-one units to consider ... from what I've read, don't consider anything cheaper than the MPP or Growatts.

Some people do buy the 24V, 240V single phase output all-in-ones (European models) and then use a transformer to obtain split phase output in the USA but it seems easier to me to just buy a 2nd Growatt and use their in-built parallel function if you really want the split-phase output. If you don't need the split-phase output/have 240v devices you really want to run, then stick to what you're currently doing.

Seems like the hybrid can be set up as a grid-tie unit if you desired ... the MSD can not. I'm sure there are other minor differences but I can't find them ... ahhh ... with some further reading, I believe the MSD is also NOT split-phase supportable ... parallel yes, 3-phase yes, split-phase no ... I could be wrong though, the literature is not very clear.
 

Eaks77

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Jul 19, 2021
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@derekisastro Thank you for your response!

Yeaaaa. Disregard the 1500W/1800W comment. I had a different electrician over today... All is good :)

Initially I was leaning towards the MPP LV2424, but I'm now leaning towards to Growatt because it's potentially quieter... but it produces more power and is a little more effiecient. However, I have heard/read that the Growatt may have challenges with home made LifePO4 batteries... Thoughts?
 

Eaks77

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^ just as a follow-up... after further reading, it sounds like if I'm using a homemade LifePO4 battery bank, with a BMS... It's unable to communicate with the Growatt unit and I therefore need to adjust some settings.
 

derekisastro

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^ just as a follow-up... after further reading, it sounds like if I'm using a homemade LifePO4 battery bank, with a BMS... It's unable to communicate with the Growatt unit and I therefore need to adjust some settings.
I come from a pretty heavy DIY background so not having the BMS communicate with an inverter has never been an issue ... to be honest, there's some benefit to having them as independently operating units.

Ultimately, think of the battery BMS as the 'last line of defense'. Set the inverter low voltage cut-off and max voltage charging cut-off as well as the max charging current to be 'below' (or higher than, in the case of the low voltage cut-off) the limits of your BMS and you're golden.

There as some good, detailed posts on this forum about what settings to use for homemade LiFePO4 banks with your Growatt.
 

Eaks77

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@derekisastro
Thank you for your response!

This question is not on topic of the inverter, but hoping you can still answer.... It's regarding BMS's. This will probably be a very novice question, so forgive me.... BMS's are rated for different amps.... If my battery bank will be 310AH, I don't need to find a BMS that's rated for the Amp Hours, correct? (because amps and amp hours are two different things). However, I do need to pick a BMS to manage the battery and the typical loads it'll be dealing with... correct?

Solar charge shouldn't be more than 30amps and if I'm using all 3000W of the inverter, I'll be drawing ~140Amps.... Which means I should be fine with a 150 Amp BMS, correct?
 

derekisastro

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Jan 27, 2021
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@derekisastro
Thank you for your response!

This question is not on topic of the inverter, but hoping you can still answer.... It's regarding BMS's. This will probably be a very novice question, so forgive me.... BMS's are rated for different amps.... If my battery bank will be 310AH, I don't need to find a BMS that's rated for the Amp Hours, correct? (because amps and amp hours are two different things). However, I do need to pick a BMS to manage the battery and the typical loads it'll be dealing with... correct?

Solar charge shouldn't be more than 30amps and if I'm using all 3000W of the inverter, I'll be drawing ~140Amps.... Which means I should be fine with a 150 Amp BMS, correct?
You've got it all correct.

You do NOT need to find a BMS that matches the Amp Hours.

Amps is an instantaneous use rating, Amp Hours is a timed-based capacity use rating (as the name implies), so yes, you will need a BMS that matches the anticipated loads. With a 3000W inverter from a "nominal" 24V LiFePO4 battery bank, you'll be at 125 Amps at the maximum output of 3000W. At 48V you'll only draw half that (62.5 Amps), at 12V twice that (250 Amps).
 
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