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budget 5kW backup system build

Featured Replies

Hi Guys

I am looking for some advice on a budget 5kW backup system build
I don’t need bells and whistles, just something that is basic and works, and is the best bang for buck
These are the inverters and batteries I have been looking at :

Growatt SPF5000ES
Kodak / Axpert VMIII 5kW 48V
Luxpower  SNA 5kW

Revolt R100
Hubble AM1      
Shoto 5.12kWh

Which combo would you recommend or avoid?

Any others that I should check?

Thanks in advance!

I am also interested in feedback on this question since I am also in the market for a similar solution.... Here are some of my views:

Growatt/Kodak/Axpert all appears to be reasonable quality Inverters that can keep the lights on when the power goes off. However, my choice would be the LuxPower because it has "blending" functionality that the others don't have (based on the research I have done to date) - this function can supply your load from both PV and the grid - watch here

 

This is significant because it can actually result in more $$$ savings!

For a battery I like the Hubble because it appears to be high quality, 1C rated with high cycle life, has internal fire suppression and is supported by the LuxPower Inverter. I am not aware of an AM-1 battery from Hubble but certainly the AM-2 & AM-5 versions for ~5Kw/~48V systems.

  • Author

Thanks Andre for the reply.

Sorry I did mean the Hubble AM2 

The Growatt can also do AC DC blending , see vid below , and I seen a few posts on this forum confirming this,

I am leaning towards the Growatt at this stage .. LuxPower is a close second.

So Growatt/Luxpower best price is about R13K currently and with a revov battery R24K so that's R37K

Trying to figure out the install now, I plan to DIY as much as possible and then bring in an electrician to do the DB wiring and COC. Hoping to get it done for under R40K

 

 

18 hours ago, Andre48 said:

However, my choice would be the LuxPower because it has "blending" functionality that the others don't have (based on the research I have done to date) - this function can supply your load from both PV and the grid

All three of the listed options have that feature, so would come down to the other factors. (Although, as a pure backup solution, even that does not matter.)

I recently had to make a similar decision.  First choice would have been the Growatt - but recent firmware updates apparently bias it towards high fan speed (noisy). Never considered the Luxpower, as I do not know enough about them. So went with the Kodak. So far it works perfectly, but only a few years will tell w.r.t. reliability.

The other important consideration was the warranty - Growatt (5 year), Kodak (3 year), Luxpower (2 year).  Would again have biased me to the Growatt, if it wasn't for all the noise complaints.

Following this thread with keen interest in doing something similar (DIY build)

Never really looked into this before so I have some possibly silly questions to ask:

Why is one battery brand preferred over another? There seems to be quite a big difference in price. The Revov R100 5.1kWh is priced around the same as a pylontech US3000C 3.6kWh (~R22k). Is there a reason not to buy the Revov? Seems a good deal?  

 

 

  • Author
1 hour ago, JustinSchoeman said:

All three of the listed options have that feature, so would come down to the other factors. (Although, as a pure backup solution, even that does not matter.)

I recently had to make a similar decision.  First choice would have been the Growatt - but recent firmware updates apparently bias it towards high fan speed (noisy). Never considered the Luxpower, as I do not know enough about them. So went with the Kodak. So far it works perfectly, but only a few years will tell w.r.t. reliability.

The other important consideration was the warranty - Growatt (5 year), Kodak (3 year), Luxpower (2 year).  Would again have biased me to the Growatt, if it wasn't for all the noise complaints.

thanks good point. I hadn't considered warranty. Looks like Growatt is the best option for me.

  • Author
22 minutes ago, h4ns3n said:

Following this thread with keen interest in doing something similar (DIY build)

Never really looked into this before so I have some possibly silly questions to ask:

Why is one battery brand preferred over another? There seems to be quite a big difference in price. The Revov R100 5.1kWh is priced around the same as a pylontech US3000C 3.6kWh (~R22k). Is there a reason not to buy the Revov? Seems a good deal?  

The Revov is a "second life" cell. You can read on their site. https://revov.co.za/2ndlife/r100-2ndlife-battery/ 

The warranty and specs are still very good, so for me it seems to be the best budget option.

Other thing to consider is if the Growatt will talk to the Revov BMS.. still looking for a definitive answer on that. 

Having had my Growatt for over a year now, I can attest to the fan noise. The Fan speed is triggered by load, which ensures the Inverter does stay cool.
Having known about it before hand I planned it to be placed in the Garage, so the noise is no issue.
The Inverter did pack up after a year but was repaired under guarantee and is working perfectly again. Mosfets were replaced.
My neighbour got himself the Luxpower and just two weeks ago added a second Luxpower in parallel. Fan noise about the same as on the Growatt, but he also has his equipment in the garage. His experience with his 2 X AM-2  has been on par too.
Gave me the chance to explore that option too, and the dual MPPT is something that would benefit me as I have 2 parallel strings now feeding the Growatt, where the one string is subject to shading certain times of day, resulting in reduced solar yield. Not too bad but had I had the Luxpower the full sun string would feed without any losses. 
Either one of these Inverters will serve the purpose.

Edited by zsde

  • Author
5 minutes ago, zsde said:

Having had my Growatt for over a year now, I can attest to the fan noise. The Fan speed is triggered by load, which ensures the Inverter does stay cool.
Having known about it before hand I planned it to be placed in the Garage, so the noise is no issue.
The Inverter did pack up after a year but was repaired under guarantee and is working perfectly again. Mosfets were replaced.
My neighbour got himself the Luxpower and just two weeks ago added a second Luxpower in parallel. Fan noise about the same as on the Growatt, but he also has his equipment in the garage. His experience with his 2 X AM-2  has been on par too.
Gave me the chance to explore that option too, and the dual MPPT is something that would benefit me as I have 2 parallel strings now feeding the Growatt, where the one string is subject to shading certain times of day, resulting in reduced solar yield. Not too bad but I I had the Luxpower the full sun string would feed without any losses. 
Either one of these Inverters will serve the purpose.

Thanks zsde - very useful feedback - what battery are you using?

Edited by Brendonvdh

2 minutes ago, Brendonvdh said:

Thanks zsde - very useful feedback - what battery are you using?

Also a Hubble AM-2. Original version with original Firmware. 382 cycles so far with zero loss of capacity. Very satisfied.

  • Author

I been crawling the interwebs for good deals. It is amazing how many suppliers are out there, and some of them are clearly scams 

Best deal I found is:

Growatt SPF5000ES with Wifi dongle R12500 / ellyhillpower

Dyness 4.8kwh li battery R24000 / jcsolarpanels

R36500 Total

Its probably not the best time to be looking for deals in the middle of stage 4 when everyone in SA is shopping.. 🙄

14 hours ago, Brendonvdh said:

I been crawling the interwebs for good deals. It is amazing how many suppliers are out there, and some of them are clearly scams 

Best deal I found is:

Growatt SPF5000ES with Wifi dongle R12500 / ellyhillpower

Dyness 4.8kwh li battery R24000 / jcsolarpanels

R36500 Total

Its probably not the best time to be looking for deals in the middle of stage 4 when everyone in SA is shopping.. 🙄

 

28 minutes ago, h4ns3n said:

I've ended up finding these guys:

https://www.solarwaysuppliers.co.za/product/5kw-growatt-dyness-4-8kwh-lite/

The price of R39,499 with all the extras and one place to handle the warranty for both the inverter and battery seem to make up for the slight increase in price. 

Powerforumstore have some interesting additions to their range of inverters and batteries, including Deye, Luxpower, Solax, Magneto, Greenrich, Halo and Revov, the combos could come in at even better than that. I think that it's worth giving them a call.

  • Author
1 hour ago, h4ns3n said:

I've ended up finding these guys:

https://www.solarwaysuppliers.co.za/product/5kw-growatt-dyness-4-8kwh-lite/

The price of R39,499 with all the extras and one place to handle the warranty for both the inverter and battery seem to make up for the slight increase in price. 

Yeah I also found that deal. I'm wonder how much those extra's are worth. I'm probably starting to split hairs now. You have a good point about getting everything from one place. 

Edited by Brendonvdh

  • Author
1 hour ago, YellowTapemeasure said:

Powerforumstore have some interesting additions to their range of inverters and batteries, including Deye, Luxpower, Solax, Magneto, Greenrich, Halo and Revov, the combos could come in at even better than that. I think that it's worth giving them a call.

Thanks you are right, no sure why I didn't look their properly before.

Best deal there is the LuxPower R 12,144.00 and Revov R100  R 22,719.40 total R34863. Very good deal.

Now to try figure out if the LuxPower can talk to the Revov BMS..

Edited by Brendonvdh

My experience tells me that you want to be sure that batteries and inverter will get on with each other. Specifically you need working comms between BMS and inverter so that your battery gets an accurate SOC and so the BMS can send the correct settings to the inverter. So check the combinations here. All the battery manufacturer web sites should provide information as to what inverters they are compatible with.

4 hours ago, Brendonvdh said:

Thanks you are right, no sure why I didn't look their properly before.

Best deal there is the LuxPower R 12,144.00 and Revov R100  R 22,719.40 total R34863. Very good deal.

Now to try figure out if the LuxPower can talk to the Revov BMS..

The problem with the R100 is 0,5C discharge, so it will give you around 2500W unless you pair it with a friend in parallel. You might want to consider the Greenrich U-P3686 instead, at least it will give around 3600W for the same price less a little capacity, and a better long-term solution:

https://powerforum-store.co.za/collections/batterys/products/greenrich-u-p3686-lithium-battery-3-686kwh-51-2v

Edited by YellowTapemeasure

12 minutes ago, YellowTapemeasure said:

The problem with the R100 is 0,5C discharge, so it will give you around 2500W unless you pair it with a friend in parallel. You might want to consider the Greenrich U-P3686 instead, at least it will give around 3600W for the same price less a little capacity, and a better long-term solution:

https://powerforum-store.co.za/collections/batterys/products/greenrich-u-p3686-lithium-battery-3-686kwh-51-2v

The Greenrich is actually even better than that, it's a 1.5C battery. According to the spec:

Continuous Discharge Rate (Normal Use): 5000 W

  • Author
1 hour ago, YellowTapemeasure said:

The problem with the R100 is 0,5C discharge, so it will give you around 2500W unless you pair it with a friend in parallel. You might want to consider the Greenrich U-P3686 instead, at least it will give around 3600W for the same price less a little capacity, and a better long-term solution:

Thanks I guess it depends what's more important:

Being able to support more than 2.5kW load during load shedding and no PV

or 

Having extra 1.5kW of storage

Extra storage means more savings/quicker return on investment once I add PV, and I reckon we can manage with the 2.5kW load max.

28 minutes ago, Brendonvdh said:

Thanks I guess it depends what's more important:

Being able to support more than 2.5kW load during load shedding and no PV

or 

Having extra 1.5kW of storage

Extra storage means more savings/quicker return on investment once I add PV, and I reckon we can manage with the 2.5kW load max.

When are you planning the PV?

It's important to do so soonest, because you will soon realise that charging from Eskom becomes very expensive very soon due to conversion losses.

Edited by YellowTapemeasure

  • Author

So assuming I get this build ... 5kW inverter connected to a single 5kW 0.5C battery only, (battery max output 2.5kW)

What happens if the load exceeds 2.5kW during load shedding? Does the inverter switch off?

and then while on grid power, what happens if the load exceeds 5kW Does the inverter pass through more than its 5kW limit or will it switch off?

 

 

 

Edited by Brendonvdh

23 hours ago, Brendonvdh said:

So assuming I get this build ... 5kW inverter connected to a single 5kW 0.5C battery only, (battery max output 2.5kW)

What happens if the load exceeds 2.5kW during load shedding? Does the inverter switch off?

and then while on grid power, what happens if the load exceeds 5kW Does the inverter pass through more than its 5kW limit or will it switch off?

 

 

 

Using the Sunsynk as reference here

If load exceeds 2.5 during LS the inverter will trip then restart

While on grid the inverter will pass through up to 7.5kw I think then trip

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