Installing Solar have Legacy Issues

Y

YeOldeOke

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Pretoria
Some sage advice would be welcome.

My current setup grew in bits and pieces in trying to deal with the chaos created by ESKOM and the municipality. Substations blowing up and being burnt down on top of load shedding, Fun innit, .

What I have is:
Office - 200AH second life Mercer battery on 12V Mercer 1200VA/720W inverter - simulated sine/square wave,
Lounge - 4x280 CATL prismatic cells first life on 12V Mercer 1200VA/720W inverter - simulated sine/square wave,

These work well.

Now upgrading to whole house solar (still grid tied for the cloudy/rainy days)
Currently use ave of 17KW/day whole house.
Have 16x280 CATL prismatic cells first life for 51V serial install. That should give me about 14KW battery backup
Thinking of this 5.5KW inverter
https://www.geewiz.co.za/solar-acce...48vdc-mppt-solar-pure-sine-wave-inverter.html
And 8x550W solar panels.

Now what to do with the 2 legacy installations, I'd like to keep the capacity....

Will the 2 MECER inverters be OK with the setup or will I have issues?
 
Get rid of them, seriously, they are like that first car you have an attachment to and don't want to get rid of even when it's clear it's going to rot in the garage.

They are modified sine wave which makes for an even more compelling reason to get rid of them, slap a good price on it and put it on MyBb or Facebook, beware of scammers.
 
Try to stop buying point-solution toys, you keep having to buy over and over again, and you will constantly be in upgrade mode (and tripping over cables). If you keep adding little bits and pieces, they all mount up to far more expense in the long term than biting the bullet and going for a properly integrated and expandable system. Moreover, they will not work with one another so you have to keep plugging things in and out. Painful.

Spend a reasonable amount of money, get a 5-8k Solis hybrid inverter with an expandable Lithium battery pack that has comms with the inverter, and sell off all of those little bits and pieces to someone less fortunate than yourself.
 
YeOldeOke said:
Some sage advice would be welcome.

My current setup grew in bits and pieces in trying to deal with the chaos created by ESKOM and the municipality. Substations blowing up and being burnt down on top of load shedding, Fun innit, .

What I have is:
Office - 200AH second life Mercer battery on 12V Mercer 1200VA/720W inverter - simulated sine/square wave,
Lounge - 4x280 CATL prismatic cells first life on 12V Mercer 1200VA/720W inverter - simulated sine/square wave,

These work well.

Now upgrading to whole house solar (still grid tied for the cloudy/rainy days)
Currently use ave of 17KW/day whole house.
Have 16x280 CATL prismatic cells first life for 51V serial install. That should give me about 14KW battery backup
Thinking of this 5.5KW inverter
https://www.geewiz.co.za/solar-acce...48vdc-mppt-solar-pure-sine-wave-inverter.html
And 8x550W solar panels.

Now what to do with the 2 legacy installations, I'd like to keep the capacity....

Will the 2 MECER inverters be OK with the setup or will I have issues?
Click to expand...


I would sell the 200ah mecer and the one inverter , and buy more cells with that cash to use with existing 4x280ah cells to build a 48/51.2v battery whatever you choose to opt for

Keeping one inverter as a backup crutch maybe in case of failure and thus also the 4s bms currently in use

Yea you can keep using mecer inverters in series with new device , though i prefer not to have devices on modified sine wave if you have a pure sine wave device
 
Last edited:
Thanks to all for the responses, I do appreciate the input and your time and knowledge.

I still am foggy on the overall picture.

Ignoring my current bits and pieces. My peak load on the new system will be 4 to 5 KW.

Will a 5.5KW hybrid inverter such as this 5.5KVA inverter be OK with a LiFePo4 16 cell 280Ah series bank (51.2V 14KW) ?
What amp BMS would I need, is 100A sufficient? 150A?
8 (or 10?) 555W solar panels.

Do I need to go bigger? I don't foresee any future expansion as appliances are getting more efficient in power usage and there's no more space for extra appliances in the house. The geyser I'll put on a timer to only operate during the afternoons, if no sun it'll draw from the grid else of course batteries if no sun and no grid power.

The Solis inverters look great but the price is ouch! What would they give me that the above inverter doesn't?

Any recommended inverters?
 
Last edited:
YeOldeOke said:
Thanks to all for the responses, I do appreciate the input and your time and knowledge.

I still am foggy on the overall picture.

Ignoring my current bits and pieces. My peak load on the new system will be 4 to 5 KW.

Will a 5.5KW hybrid inverter such as this 5.5KVA inverter be OK with a LiFePo4 16 cell 280Ah series bank (51.2V 14KW) ?
What amp BMS would I need, is 100A sufficient? 150A?
8 (or 10?) 555W solar panels.

Do I need to go bigger? I don't foresee any future expansion as appliances are getting more efficient in power usage and there's no more space for extra appliances in the house. The geyser I'll put on a timer to only operate during the afternoons, if no sun it'll draw from the grid else of course batteries if no sun and no grid power.

The Solis inverters look great but the price is ouch! What would they give me that the above inverter doesn't?

Any recommended inverters?
Click to expand...
You will size your batteries based on two things: Capacity (how long you want them to deliver power for) and ability to deliver current at your chosen load. If your load is 5kW, then using a 48V battery, you need something can deliver 5000 / 48 = 104.1 Amps. A 5kWh battery will deliver this for roughly one hour (if you run it completely flat, 100% Depth of Discharge (DoD)). If you only draw 1 kW, then it will last for roughly 5 hours, and draw current at a rate of 1000 / 48 = 20.8 Amps.

Solis' new S6 is most probably the cheapest proper hybrid inverter that you should consider, cheaper than the equivalent Sunsynk and more capable. The one which you linked seems to be an axpert-type, which is hugely inefficient due to lack of blending capability and battery comms for starters. With a 5k inverter you also need to consider flexibility and expansion, which the Solis does particularly well, able to export PV to non-essential loads (just like Sunsynk) as well as AC coupling on the essential loads side.
Give the Powerforumstore a call and discuss it with some knowledgeable and trustworthy people.
 
Last edited:
YeOldeOke said:
Thanks to all for the responses, I do appreciate the input and your time and knowledge.

I still am foggy on the overall picture.

Ignoring my current bits and pieces. My peak load on the new system will be 4 to 5 KW.

Will a 5.5KW hybrid inverter such as this 5.5KVA inverter be OK with a LiFePo4 16 cell 280Ah series bank (51.2V 14KW) ?
What amp BMS would I need, is 100A sufficient? 150A?
8 (or 10?) 555W solar panels.

Do I need to go bigger? I don't foresee any future expansion as appliances are getting more efficient in power usage and there's no more space for extra appliances in the house. The geyser I'll put on a timer to only operate during the afternoons, if no sun it'll draw from the grid else of course batteries if no sun and no grid power.

The Solis inverters look great but the price is ouch! What would they give me that the above inverter doesn't?

Any recommended inverters?
Click to expand...
I would go 150A bms

If you want to be able to use the batteries full range in an emergency ie 100dod

Then the voltage would go as low as 40v on the battery

5500w / 40v =137.5A on the battery side
and
5500 / 50 = where you would spend most of your time 110A so 100A falls short ie your 5500w inverter is then a 5000w inverter
many of these inverters will go over for a short period of time ie my 5000w axpert will go up to 5500w for a short period without tripping overload

Edit
Now normally most people would scale down usage if they know they are close to empty so would need perfect storm to have a shutdown
and the charging amps of the bms has to be considered too if 5555w solar with 300w base load would mean 5255w /50v = 105a charging amps so if you have a bms that has charging amps 0.5c (some have the charge be half of discharge) then you would lose more than half of your solar capacity on a 100A and quarter lost on a 150A bms with the 1c/0.5c config, ie i would make sure to get a bms that can handle all and some for those days you get more than rated capacity


Solar panel count depends on your consumption , most tend to go as high as the inverter can handle , for winter and bad weather
 
Last edited:
RonSwanson said:
You will size your batteries based on two things: Capacity (how long you want them to deliver power for) and ability to deliver current at your chosen load. If your load is 5kW, then using a 48V battery, you need something can deliver 5000 / 48 = 104.1 Amps. A 5kWh battery will deliver this for roughly one hour (if you run it completely flat, 100% Depth of Discharge (DoD)). If you only draw 1 kW, then it will last for roughly 5 hours, and draw current at a rate of 1000 / 48 = 20.8 Amps.

Solis' new S6 is most probably the cheapest proper hybrid inverter that you should consider, cheaper than the equivalent Sunsynk and more capable. The one which you linked seems to be an axpert-type, which is hugely inefficient due to lack of blending capability and battery comms for starters. With a 5k inverter you also need to consider flexibility and expansion, which the Solis does particularly well, able to export PV to non-essential loads (just like Sunsynk) as well as AC coupling on the essential loads side.
Give the Powerforumstore a call and discuss it with some knowledgeable and trustworthy people.
Click to expand...
In what way is the Soils more capable than the Sunsunk…..

I really can’t think of anything more I would want my Sunsynk to possibly do??
 
NathanEL said:
In what way is the Soils more capable than the Sunsunk…..

I really can’t think of anything more I would want my Sunsynk to possibly do??
Click to expand...
No product is perfect

Each has their tradeoffs, some hearsay info i heard ie can't attest to its validity

The way the sunsynk forms its sine wave they found to affect some sensitive equipment more than other inverters

just because we can't allways see the flaws doesn't mean they don't exist

like this thread i suppose

My PC(PSU) is making white noise when am on Sunsynk/Deye

My PC(PSU) is making white noise when am on Sunsynk/Deye even my cordless phone speaker is very noisy only when i am on the inverter please any help ? what i should do ?
powerforum.co.za powerforum.co.za
 
NathanEL said:
In what way is the Soils more capable than the Sunsunk…..

I really can’t think of anything more I would want my Sunsynk to possibly do??
Click to expand...
If you are happy with your SS the that's great. I have 2 at different installs, and I am also relatively happy, but if I were to install again today I would go for the Solis S6. If you want to know why then contact a competent salesperson to explain AC coupling to you.
 
RonSwanson said:
Try to stop buying point-solution toys, you keep having to buy over and over again, and you will constantly be in upgrade mode (and tripping over cables). If you keep adding little bits and pieces, they all mount up to far more expense in the long term than biting the bullet and going for a properly integrated and expandable system. Moreover, they will not work with one another so you have to keep plugging things in and out. Painful.

Spend a reasonable amount of money, get a 5-8k Solis hybrid inverter with an expandable Lithium battery pack that has comms with the inverter, and sell off all of those little bits and pieces to someone less fortunate than yourself.
Click to expand...
Trying to do that now:

https://mybroadband.co.za/forum/thr...lly-built-balanced-for-sale-pretoria.1339015/

Interested? :)
 
There;s the small matter of quality and lifetime. Those I would not touch with a 10-foot pole I;m afraid.. I have one coming out soon on that level, and it'll probably go for 3000 / 4000 with inverter and all. I'm NOT trying to be snobbish or anything., buy it's what I expected.

It amounts to casual insults
 
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