How many 5,5Kw Hubble batteries can I use with 2 Lux 5Kw SNA invertors

20 minutes ago, Lionel said:

How many 5,5Kw Hubble batteries can I use with 2 Lux 5Kw SNA invertors

The inverter has no limit. Hubble indicate 8 batteries in total. 

Edited December 17, 20222 yr by Scorp007

On 2022/12/17 at 1:09 PM, Lionel said:

How many 5,5Kw Hubble batteries can I use with 2 Lux 5Kw SNA invertors

No limit. The more battery capacity the better. In particular in view of extended load shedding duration.

23 minutes ago, Beat said:

No limit. The more battery capacity the better. In particular in view of extended load shedding duration.

From Hubble. 

7 hours ago, Scorp007 said:

From Hubble. 

That is for the AM5
The AM2 5,5kW batteries are actually 15 per string 

8 hours ago, Superfly said:

I see battery prices are still increasing - I thought in winter it would rather (prob the higher loadshedding increasing demand) - but yes, rather get more batteries - CoCT pays 50% of what you buy from them .. so I'd rather store the extra PV. 

Cheers

I see the high demand worldwide might continue. Energy drivers/price is totally different to a decade ago. We see the LS side as it impacts us all. 

Nevertheless adding battery capacity has benefits on various levels:

• It helps to harvest more solar energy, thus reduces cost for purchased electricity. To consider in view of hiking tariffs.
• Provides more reliability in view of potentially more severe load shedding.
• Attenuates the so called kettle effect (battery voltage drop due to heavy load).
• Reduces stress on the batteries due to heavy load, thus potentially extending life time of the batteries.
• Increases overall system stability.

Any other arguments?

5 minutes ago, Beat said:

Any other arguments?

One more. It keeps you operational in the unlikely event of a battery failure. A single battery ends the independence if something does go wrong  😉

The only argument against so many batteries is the cost and even with increasing tariffs one has to weigh up the financial outlay vs the cost of using a small shortfall if and when required.  It all depends on one's usage/consumption.

4 hours ago, zsde said:

One more. It keeps you operational in the unlikely event of a battery failure. A single battery ends the independence if something does go wrong  😉

The only argument against so many batteries is the cost and even with increasing tariffs one has to weigh up the financial outlay vs the cost of using a small shortfall if and when required.  It all depends on one's usage/consumption.

Sometimes one must add figures. Say you have a 5kwh battery and run short with 1kwh during the period up to the panels starting to charge. You could buy some security and add another 5kwh similar battery. At the current prices if power did not increase which we know is a dream the time to pay off will be about 30 years. May be just a better call to manage this 1kwh daily load. 

16 hours ago, Scorp007 said:

Sometimes one must add figures. Say you have a 5kwh battery and run short with 1kwh during the period up to the panels starting to charge. You could buy some security and add another 5kwh similar battery. At the current prices if power did not increase which we know is a dream the time to pay off will be about 30 years. May be just a better call to manage this 1kwh daily load. 

Basically right! But I'm afraid that days may come when your issue no longer is financial viability but "Do I have electricity or not". That may become crucial for the survival of your freezer and fridge content as well as for your comfort. I find it difficult to attribute any financial figure to that.

22 hours ago, Beat said:

Any other arguments?

I cannot discount your points, they are all valid and increased capacity is always more than welcome. My only point of contention is charging...

If you have the solar available to fully charge the batteries and support your load, you are more than set. I have seen so many people bringing batteries in here because charge management was thrown out the window. A lot of installers set it up to support load first, charge secondary but don't make sure there is enough to charge the batteries or they use grid as a source to charge the batteries which doesn't save money. With the addition of another battery, the charging time doubles or the charging current doubles, forget this and you'll run the batteries into the ground in no time flat. So make sure you understand this dynamic before throwing another battery onto your system... 

37 minutes ago, Superfly said:

Not sure if my calcs are just wonky or too simplistic but I see it like this...

R30k battery = 4.8kWh / day 

CoCT Domesttic rate ~R3.00 / kWh x 4.8 = R14,40 / day = R5 256 / year 

Break even = R30 000 / R5 256 = 5,7 years.

Increased rates will decrease the period even further.

You are close to real. Cost of power could be a lot lower per unit. My basis was if you read it again if you only need 1kwh per day but buy the 5kwh battery to match a existing battery. 

Not many people would use 100% of the battery capacity and if the do they will change it a lot sooner than dotting it down on paper and factoring in a 10 year life cycle. 

What about the calc if you need 4 days to get 1 full charge in winter in CoCT. 

So yes as @zsde

Indicated it will vary per individual. You also need to order enough sunshine each day in order to charge the 5kwh before you can use it. Not that easy in some provinces. 

I think we all have valid points. 

Edited December 21, 20222 yr by Scorp007

I personally think we all have different opinions on the return on the investment.

In my case first and for most the main objective was to beat load shedding. The savings from PV and battery as far as I am concern is like the cherry on top of the cake.

So far according to my usage I've saved from both battery and PV about R 13,500.00.

However, based on my archived data since my installation 15 months ago I've drawn 1.233 megawatts from my battery. In my municipality price per Kw R 1.80 I've saved quite allot, the Battery ROI should be roughly 6 years.

8 minutes ago, Scorp007 said:

it will vary per individual.

Everyone's experience over time will determine the feasibility.
Even with cloudy summer days up on the Highveld I could charge my single battery 2 to 3 times. Am off the grid, meaning I control solar or grid with a change over, i.e. no grid into my Inverter. I decide and control when I need some grid power. 
Our prepaid tariff is R2/kw. And I average 20kW a month, some months I use zero. That makes R40 a month, i.e. R480 per year or R4800 over 10 years. So lets double that for inflationary purposes, it would still be around R10 000 over 10 years. 
My battery is just enough in Winter and I have to manage the consumption over night very carefully to make it last. But then again in winter I produce more consistently PV than in Summer. 
Another battery would make life a lot more worry free, but does it make financial sense? NO. Does it make practical sense, yes, of course it does. Then comes the question of battery lifetime. Let's work on the claimed 10years that most market. So after 10 years I would have to replace both batteries which would have shot up in price as well, just like the grid prices.
It's all about priorities and cost. In my case I am hard pressed to spend another R30k when I know that I am managing with the battery I have. 

Every single one of us needs to analyse their priorities and then manage that which we installed, or expand as needed and justified.
Having said that, if money is no object, then why not become a supplier to the neighbourhood?😉
 

6 minutes ago, zsde said:

Everyone's experience over time will determine the feasibility.
Even with cloudy summer days up on the Highveld I could charge my single battery 2 to 3 times. Am off the grid, meaning I control solar or grid with a change over, i.e. no grid into my Inverter. I decide and control when I need some grid power. 
Our prepaid tariff is R2/kw. And I average 20kW a month, some months I use zero. That makes R40 a month, i.e. R480 per year or R4800 over 10 years. So lets double that for inflationary purposes, it would still be around R10 000 over 10 years. 
My battery is just enough in Winter and I have to manage the consumption over night very carefully to make it last. But then again in winter I produce more consistently PV than in Summer. 
Another battery would make life a lot more worry free, but does it make financial sense? NO. Does it make practical sense, yes, of course it does. Then comes the question of battery lifetime. Let's work on the claimed 10years that most market. So after 10 years I would have to replace both batteries which would have shot up in price as well, just like the grid prices.
It's all about priorities and cost. In my case I am hard pressed to spend another R30k when I know that I am managing with the battery I have. 

Every single one of us needs to analyse their priorities and then manage that which we installed, or expand as needed and justified.
Having said that, if money is no object, then why not become a supplier to the neighbourhood?😉
 

@zsde . As you rightly say we all live under different circumstances, I my case I cannot be without grid power to supplement my electricity usage. Household of 6 with an average daily consumption of 23 Kw, to be off grid I would need 15 Kw of storage capacity. However, I've managed to bring my dependence on grid to +- 6 Kw per day, also I've been able to survive even the 8 hour a day load shedding, I have to admit there have been days that I had to charge my battery with +_ 2 Kw from grid.

On 2022/12/21 at 12:54 PM, Superfly said:

Problem with that is we only get R0.98c/kWh exported.. compared to paying on Home User tariff (lower usage) of R2.62/kWh -  hence my contention that storing additional power in batteries is more economically viable ( for me, anyway).. Wish I could afford to be more charitable... but it is what it is.. 

Supplying the neighbourhood could be the other consumers so they pay for your export instead of selling to a munic. Very much like some complexes do where they have 1 feed from the munic. Saves them the munic rate if you export. A simple prepaid sub letting prepaid meter that won't trip but does keep the exported units in a registry. 

My R5000 cost for inverter has generated over 8000kwh in power saved from PV over nearly 4 yrs. System is for own consumption. My back up has no stored data and is therefore not part of the saving. 

Edited December 22, 20222 yr by Scorp007