Advice needed

[MNK1234]

Hi All,

 

I am new to the forum. I want to install a small solar/backup system for my home.

The load that I am planning to backup is a maximum of 1kW made up of lights and plugs (TV, router, laptop, phone charger). 

I would like to be able to supply the load with solar and then use Eskom to supplement the load. I would also like to have batteries as backup during load shedding. I think this is called an On Grid hybrid system. 

 

 

My question now is which inverter would work for this setup. I am considering the Mecer Axpert Hybrid inverter but have received mixed feedback with some saying its not a full hybrid inverter.

Then the second question is on the battery. I know LI-ion batteries are better quality but at a cost. Would led-acid/gel battery last if they used as back-up and thus not cycled as much. So having the setup being solar-eskom-battery. I've also read that the Axpert inverter has issues when charging LI-ion batteries due to the MPPT setup.

Then in terms of capacity I see LI-ion batteries are rated in Wh and lead-acid is in Ah. So to compare like for like is it simply just multiplying the lead-acid battery Ah by the rated voltage. So a 12V/100Ah lead acid would be 1200Wh.

And lastly is there a database where I can find reliable installers that are well priced and can give real advice.

Thanks in advance

Regards

Nadeem

[Otto ES]

Hi

I am also a Noob but note that when you compare the capacity of lead-acid with Li-ion that you can not discharge them to the same level. The lead -acid you should only discharge to about 50% while you can discharge the Li-ion to 10% (90% use-able)

[SYC]

7 hours ago, MNK1234 said:

My question now is which inverter would work for this setup. I am considering the Mecer Axpert Hybrid inverter but have received mixed feedback with some saying its not a full hybrid inverter.

The Axpert king would be best bet in my opinion

7 hours ago, MNK1234 said:

Then the second question is on the battery. I know LI-ion batteries are better quality but at a cost. Would led-acid/gel battery last if they used as back-up and thus not cycled as much. So having the setup being solar-eskom-battery. I've also read that the Axpert inverter has issues when charging LI-ion batteries due to the MPPT setup.

I've had the Axpert 5k , Axpert 450V and got Axpert King with Pylontech and it works perfectly fine from my experience

 

7 hours ago, MNK1234 said:

Then in terms of capacity I see LI-ion batteries are rated in Wh and lead-acid is in Ah. So to compare like for like is it simply just multiplying the lead-acid battery Ah by the rated voltage. So a 12V/100Ah lead acid would be 1200Wh.

Otto Es Is correct that Lead acid/Gel should only discharged to 50% so actually it's only 600W

Li-on is the way to go in my opinion cost way more initially but long term cost effective 

[Warlok]

And don't forget to get a Raspberry PI to control and monitor the system. Maybe put the fridge on it to? (To keep the cooldrinks cold)

Jaco gave me an answer on the battery side of things. Best answer ever. Thanks Jaco

[MNK1234]

With these Trojan batteries LA or LI-ion?

[Moe Joe]

The Goodwe Es is the most suitable. The Axperts cannot combine grid and solar power. So if the axpert is generating 3kw and your demand is 4kw, 4kw will be pulled from the Grid. 

 

You don't need any PI to monitor generation either. It comes with wifi and access to Sems portal. 

Edited January 16, 2020 by Moe Joe

[Coulomb]

42 minutes ago, Moe Joe said:

So if the axpert is generating 3kw and your demand is 4kw, 4kw will be pulled from the Grid.

If it happens to be in line mode, yes. But if the battery has enough charge, 0 kW will be pulled from the grid, and 1 kW (plus losses) will come from the battery, and of course the balance of 3 kW comes from solar.

[MNK1234]

So with the normal axpert (not king) is it not possible to have the setup where primary is solar and supplementary is eskom with batteries only kicking in when eskom is not available?

[Coulomb]

11 hours ago, MNK1234 said:

So with the normal axpert (not king) is it not possible to have the setup where primary is solar and supplementary is eskom with batteries only kicking in when eskom is not available?

You can get very close to this, as long as you have reasonable battery and solar capacity. Then, most of the time, solar and/or battery provides the loads, and utility supplies loads (and optionally charges the battery) only when needed. When utility is providing the loads, all load power comes from utility; there is no blending of grid and solar power (assuming a non-King Axpert). At that time, all solar power goes to charging the battery, which makes it more likely that the battery can take over from utility.

[MNK1234]

That makes sense.

 

And in terms of battery is with worth going Lithium? I understand that the charge controller on the axpert needs adjustments to make it work.

 

One of the suppliers suggested the discovery batterty EV27A-A which apparently has like 10 years usable life. Alternatively what other cost effective solutions for batteries? 

 

https://discoverbattery.com/assets/dropbox/Datasheets/en/EV27A-A.pdf 

[Coulomb]

5 hours ago, MNK1234 said:

And in terms of battery is with worth going Lithium?

It's generally accepted now that lithium batteries are cheaper in the long term, and are far less trouble. However, not everyone can afford the steep up-front cost.

5 hours ago, MNK1234 said:

I understand that the charge controller on the axpert needs adjustments to make it work.

It's just a few settings on the Axpert. Though as I mentioned recently, it's a good idea to add a Victron BMV and ICC.