The Battery Thread (Solar / Inverter)

[Speedster]

Would it start the motor tho as the power slowly comes online in the morning?

You'd probably have to work in some form of smart switch that only turns on once sufficient power is generated. I'm not sure, haven't done it but am sure there must be a way.

 

[spiff]

@Lupus
@Speedster

or something like this

or a cheaper this one

 

[Lupus]

@Lupus
@Speedster

or something like this

or a cheaper this one

Why not just a proper inverter?

 

[Speedster]

Why not just a proper inverter?

He needs a soft start for the pump.

 

[thehuman]

You'd probably have to work in some form of smart switch that only turns on once sufficient power is generated. I'm not sure, haven't done it but am sure there must be a way.

Micro inverter after pump timer could work , if it 1000w pump fit a 1000w of panels.

He should be safe from back feeding into the grid and any extra power pump needs will be drawn from the grid .

I will set timer centered around when sun the highest .

 

[sh33p]

Great thread - amazingly informative! Apologies if this has been asked before, but I couldn't find anywhere here or elsewhere:

I've got 4 x 12V 102Ah Royals connected to a pure sine inverter and it's been working happily for the last 4 years or so. Now one of the batteries needs to be replaced (there's a little indicator on it stating so, and it's making 'puffing' noises releasing some gas?).

The batteries are connected two-by-two, so two in series to make 24V, then those two 24V in parallel into the inverter.

What's best-practice for the replacement? Do I need to replace the whole set, or just one of the parallel legs, or can I just swap out the dud one? Any advice?

Cheers.

 

[Sinbad]

Great thread - amazingly informative! Apologies if this has been asked before, but I couldn't find anywhere here or elsewhere:

I've got 4 x 12V 102Ah Royals connected to a pure sine inverter and it's been working happily for the last 4 years or so. Now one of the batteries needs to be replaced (there's a little indicator on it stating so, and it's making 'puffing' noises releasing some gas?).

The batteries are connected two-by-two, so two in series to make 24V, then those two 24V in parallel into the inverter.

What's best-practice for the replacement? Do I need to replace the whole set, or just one of the parallel legs, or can I just swap out the dud one? Any advice?

Cheers.

I'd look at one of the black friday lithium specials if I were you (and your inverter supports it).

 

[wingnut771]

Great thread - amazingly informative! Apologies if this has been asked before, but I couldn't find anywhere here or elsewhere:

I've got 4 x 12V 102Ah Royals connected to a pure sine inverter and it's been working happily for the last 4 years or so. Now one of the batteries needs to be replaced (there's a little indicator on it stating so, and it's making 'puffing' noises releasing some gas?).

The batteries are connected two-by-two, so two in series to make 24V, then those two 24V in parallel into the inverter.

What's best-practice for the replacement? Do I need to replace the whole set, or just one of the parallel legs, or can I just swap out the dud one? Any advice?

Cheers.

Time to go LFP as you would have to replace the whole set.

 

[Neuk_]

I'd look at one of the black friday lithium specials if I were you (and your inverter supports it).

Agreed, the useability and life span of LiFePo makes them far more 'affordable' than traditional lead acid batteries. I am patiently waiting for our lead acid's to die before I replace them with LiFePo.

 

[sh33p]

I'd look at one of the black friday lithium specials if I were you (and your inverter supports it).

Time to go LFP as you would have to replace the whole set.

Thanks for the suggestions, so follow-up questions:

1. is there any risk of me leaving the dud battery in (making it's little "pfft" noises) and running them all down to that state?

2. how will I know if my UPS supports LFPs? It's branded "Peak" (it looks like a rebrand of "Power Star" because it looks very similar to this) and has the following options:
Gel U.S.A
A.G.M.1
A.G.M.2
Sealed lead acid
Gel european
Open lead acid
Calcium(open)

3. any recommendations on where to get the LFPs with black friday specials?

 

[netstrider]

Thanks for the suggestions, so follow-up questions:

1. is there any risk of me leaving the dud battery in (making it's little "pfft" noises) and running them all down to that state?

2. how will I know if my UPS supports LFPs? It's branded "Peak" (it looks like a rebrand of "Power Star" because it looks very similar to this) and has the following options:
Gel U.S.A
A.G.M.1
A.G.M.2
Sealed lead acid
Gel european
Open lead acid
Calcium(open)

3. any recommendations on where to get the LFPs with black friday specials?

1. I most certainly would not risk it. Potential fire hazard.
2. Does not appear to officially support LFP, although it may work.
3. Can't help you with this one, unfortunately.

 

[The_Traveller]

Great thread - amazingly informative! Apologies if this has been asked before, but I couldn't find anywhere here or elsewhere:

I've got 4 x 12V 102Ah Royals connected to a pure sine inverter and it's been working happily for the last 4 years or so. Now one of the batteries needs to be replaced (there's a little indicator on it stating so, and it's making 'puffing' noises releasing some gas?).

The batteries are connected two-by-two, so two in series to make 24V, then those two 24V in parallel into the inverter.

What's best-practice for the replacement? Do I need to replace the whole set, or just one of the parallel legs, or can I just swap out the dud one? Any advice?

Cheers.

If you got the money to buy Lithium batteries then surely you can buy a new inverter supporting the lithium charging.

Your inverter most definately wont charge a lithium battery and you will end up damaging it.

Rather buy a new set of Royal batteries and run for another 4 years.

 

[Paul_S]

Wasting your money putting a only a fridge on solar.

A fridge uses so little power, you might as well buy some super energy efficient fridge and let that saving pay the fridge off.

Do the calculations and see for yourself.

I disagree. It's the smaller continuous loads which you want to get off Eskom because:

1. They tend to add up a lot more over a long period of time than devices which draw a lot of power for short periods (e.g. kettle, dishwasher, etc.)
2. It's cheaper to spec a solar PV system for smaller loads especially when factoring in battery storage costs. Get the heavy stuff off Eskom and solar PV. Use solar water heating, gas heating, etc.

The problem is that one can't find super efficient fridges in South Africa very easily. Nearly all of the ones sold locally are only A+. I have a A+ rated LG and a Samsung fridges and they use around 170W each when running. On a hot day/night with people opening and closing the doors regularly the duty cycle exceeds 75% so each fridge uses up to about 3kWh/day. That's up to 90kWh/month for a single fridge.
They are prime candidates for solar PV - small continuous loads so one only needs a cheap solar PV setup but obtains a good return on investment due to the amount saved.

Where can one buy A+++ rated fridges? I've looked at Bosch, KIG, LG, Samsung, Defy, etc.

Compressor run times of Samsung fridge even after cleaning the dust out of the heat exchanger. There are a couple of higher amounts from something sharing the circuit but the 170W cycle is clearly visible.

 

[The_Librarian]

He needs a soft start for the pump.

Do you get a soft start for an electrical lawnmower? When starting it up, it trips the generator's circuit breaker.

 

[TheChamp]

Do you get a soft start for an electrical lawnmower? When starting it up, it trips the generator's circuit breaker.

How much is the lawn mower power draw compared to the generator rated power?

And what current rating is the circuit breaker?

 

[The_Librarian]

How much is the lawn mower power draw compared to the generator rated power?

And what current rating is the circuit breaker?

Lawnmower = 3000W
Genny = 7000W
Will have to check when back at home what the CB rating is.

 

[Sinbad]

Lawnmower = 3000W
Genny = 7000W
Will have to check when back at home what the CB rating is.

Inrush power on that mower is going to be a lot more than that, as that cap charges up...

Maybe get a petrol mower.

 

[TheChamp]

Lawnmower = 3000W
Genny = 7000W
Will have to check when back at home what the CB rating is.

The peak startup power draw of the motor probably exceed the supplied power from the generator. I am sure there must be a soft start solution somewhere but it looks to me that you'll be better off with a petrol mower or a less powerful electric one.

 

[The_Librarian]

Inrush power on that mower is going to be a lot more than that, as that cap charges up...

Maybe get a petrol mower.

The peak startup power draw of the motor probably exceed the supplied power from the generator. I am sure there must be a soft start solution somewhere but it looks to me that you'll be better off with a petrol mower or a less powerful electric one.

Thought so. Thanks for the replies guys!

And now, back to our regular chatter Sorry for derailing it a bit.

 

[Neuk_]

I disagree. It's the smaller continuous loads which you want to get off Eskom because:

1. They tend to add up a lot more over a long period of time than devices which draw a lot of power for short periods (e.g. kettle, dishwasher, etc.)
2. It's cheaper to spec a solar PV system for smaller loads especially when factoring in battery storage costs. Get the heavy stuff off Eskom and solar PV. Use solar water heating, gas heating, etc.

The problem is that one can't find super efficient fridges in South Africa very easily. Nearly all of the ones sold locally are only A+. I have a A+ rated LG and a Samsung fridges and they use around 170W each when running. On a hot day/night with people opening and closing the doors regularly the duty cycle exceeds 75% so each fridge uses up to about 3kWh/day. That's up to 90kWh/month for a single fridge.
They are prime candidates for solar PV - small continuous loads so one only needs a cheap solar PV setup but obtains a good return on investment due to the amount saved.

Where can one buy A+++ rated fridges? I've looked at Bosch, KIG, LG, Samsung, Defy, etc.

Compressor run times of Samsung fridge even after cleaning the dust out of the heat exchanger. There are a couple of higher amounts from something sharing the circuit but the 170W cycle is clearly visible.
View attachment 955785

We have done this, everything at our house except for the oven, bedroom AC unit and two sets of plugs that the electric kettle and toaster use runs off our ESS. I make sure that the big draw appliances like the washing machine, dishwasher and tumble dryer are only run during the day to maximise PV generation. I must check our fridge and freezer combo, they are both Bosch and use very little electricity.