Solutions for loadshedding

[bmw1za]

The biggest shock(pun intended), was the price of the dual circuit breakers and cables (OMG)...

 

Totally caught me offgaurd lol

[Frosty]

The biggest shock(pun intended), was the price of the dual circuit breakers and cables (OMG)...

 

Totally caught me offgaurd lol

What did you pay?

[bmw1za]

What did you pay?

The DC 63a was R465 ... the Ac Ones were about R250 each.. power cables for batteries  R500 and cables from inverter to DB Board Max 4 m away R500 

 

This were non budgeted items... so R2000 in one go. A person's brain is like i could have bought a panel (lmao)

[Karman de Lange]

took the plunge and got an inverter(5kv Hibrid smart etc 48v)... step 2 is getting 4 x 120ah batteries(200ah a bit of a big plunge)... omg the prices(sigh). 

 

Anyone seen better battery prices than R1900 possibly ? 

 

Buy lithium, keep it at below 80% charge.  (or make your own "powerwall", thats what I did)

 

99% of "solar" batterys last 2-3 years and charges in 8-12 hrs , so not enough time between load shedding to get full charge and you will have to buy full new set way before you even think you ready.

 

"Lead acid"  gets damaged when not fully charged and lasts about 100-200 cycles (so that 2-3 cycles on "stage 2" per day which equates to  30-60 days of shedding before replacement)

 

Lithium gets damaged when fully charged (like to be 80% or lower), at 80% you get about 1000-4000 cycles.  I keep mine at 60%, in theory about >10000 cycles.

 

Happy to assist, I've not read this thread

 

My system been running since load shedding day 1 .. i've been through all the motions....

Edited February 17, 2021 by Karman de Lange

[kosmonooit]

Buy lithium, keep it at below 80% charge.  (or make your own "powerwall", thats what I did)

 

99% of "solar" batterys last 2-3 years and charges in 8-12 hrs , so not enough time between load shedding to get full charge and you will have to buy full new set way before you even think you ready.

 

"Lead acid"  gets damaged when not fully charged and lasts about 100-200 cycles (so that 2-3 cycles on "stage 2" per day which equates to  30-60 days of shedding before replacement)

 

Lithium gets damaged when fully charged (like to be 80% or lower), at 80% you get about 1000-4000 cycles.  I keep mine at 60%, in theory about >10000 cycles.

...

 

The lifespan of Lead Acid depends on depth of discharge, its on any data sheet. Also on temperature and a few other factors but mainly on how deeply they are discharged, rule of thumb is do not dip below 50%

 

Can you provide some reference on your claim that "Lithium gets damaged when fully charged"  - generally the BMS makes controls charging voltages and current to remain within specs. They will likely  get damaged if these are out of range on the parameters of the appropriate charging regime,.

 

[Karman de Lange]

The lifespan of Lead Acid depends on depth of discharge, its on any data sheet. Also on temperature and a few other factors but mainly on how deeply they are discharged, rule of thumb is do not dip below 50%

 

Can you provide some reference on your claim that "Lithium gets damaged when fully charged"  - generally the BMS makes controls charging voltages and current to remain within specs. They will likely  get damaged if these are out of range on the parameters of the appropriate charging regime,.

 

 

This is my understanding from years of reading .. but happy to get disproved: 

 

Lead acid starts forming crystals (sulfation) if not fully charged.  Thus, if you don't keep them charged they start degrading. The more they discharged, the more crystals form the short the lifespan. Basicly if you dicharge more, it stays in non fully charges state for longer. (there is plates buckling from overdischarge(heat etc) as well, but I dont have much knowlege about that

 

Sulfation: https://batteryuniversity.com/learn/article/sulfation_and_how_to_prevent_it :  There is methods to get charge faster (not the 12-14hrs mentioned), but then you need to know what you are doing and proper fully programmable charging system.

 

 

BMS ... Would love to see any "basic" bms limit current.  99% of them just tell charger to charge/not charge and keep cells at correct balance by doing a top balance.   Its up to the combination of the BMS and the Charger to determine the current/votlage of charge.

 

We run batrium with victron, it can limit the current, but its 2 steps .. either full, or lmited, its not progresive. (the mangement part, not charging curves)

 

 

 

Lithium Cycle life:

https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

 

Lifespan : (did not read this article in full, but its just something ive seen many times)

https://batteryuniversity.com/index.php/learn/article/bu_808b_what_causes_li_ion_to_die

 

The cathode (positive electrode) develops a similar restrictive layer known as electrolyte oxidation. Dr. Dahn stresses that a voltage above 4.10V/cell at elevated temperature causes this, a demise that can be more harmful than cycling a battery. The longer the battery stays in a high voltage, the faster the degradation occurs.

 

I have pack of ~1900 cells in our ~7s280p battery bank.. about 500 of those cells was at or below 1v  when I got them.  They recovered to full capacity after sitting in the state for >5 years. (this was all old discarded laptop packs).

 

They been running  now for about 2.5 years and capacity seems better now than when I build it...  I keep them at about 3.9v currently due to load shedding expectations, normally they at 3.83v. 

 

 

If it does not make sense, please excuse me .. its was quick type while trying to fix internet and program

Edited February 18, 2021 by Karman de Lange

[Vetplant]

Quick question on health and safety while scoping out my Grid-tied solution:

 

I am working on the assumption that my inverter and Pylontech LIFEPO4 battery be located close to each other to reduce cable lengths for low voltage cables.

 

I have a convenient location for our Inverter+Battery next to the main DB. But it is located in a general living area. Is that OK?

 

Or should I rather locate it all in the outside building. This will result in longer 220V cables to be run to the inverter and then back again to the DB, so somewhat of a cost penalty.

Edited February 18, 2021 by Vetplant

[TheoG]

Quick question on health and safety while scoping out my Grid-tied solution:

 

I am working on the assumption that my inverter and Pylontech LIFEPO4 battery be located close to each other to reduce cable lengths for low voltage cables.

 

I have a convenient location for our Inverter+Battery next to the main DB. But it is located in a general living area. Is that OK?

 

Or should I rather locate it all in the outside building. This will result in longer 220V cables to be run to the inverter and then back again to the DB, so somewhat of a cost penalty.

 

I would say keep it close to your DB if its not in the way.  Luckily my DB is in the garage so are my batteries, inverter & charger.

[LazyTrailRider]

Quick question on health and safety while scoping out my Grid-tied solution:

 

I am working on the assumption that my inverter and Pylontech LIFEPO4 battery be located close to each other to reduce cable lengths for low voltage cables.

 

I have a convenient location for our Inverter+Battery next to the main DB. But it is located in a general living area. Is that OK?

 

Or should I rather locate it all in the outside building. This will result in longer 220V cables to be run to the inverter and then back again to the DB, so somewhat of a cost penalty.

 

Inverters get pretty loud when under load. Depending on the size, I would not put it anywhere near a living area.

 

Ours is in the garage and I can hear it in the adjoined scullery if the door is open. If you can be fairly certain that things will stay nice and dry in your outside building, definitely go that route.

 

[Karman de Lange]

Quick question on health and safety while scoping out my Grid-tied solution:

 

I am working on the assumption that my inverter and Pylontech LIFEPO4 battery be located close to each other to reduce cable lengths for low voltage cables.

 

I have a convenient location for our Inverter+Battery next to the main DB. But it is located in a general living area. Is that OK?

 

Or should I rather locate it all in the outside building. This will result in longer 220V cables to be run to the inverter and then back again to the DB, so somewhat of a cost penalty.

 

 

1:  Make sure inverter is on the Eskom approved list.  Otherwise you will have to pay to get it approved or add another R12k unit to get it passed

 

2: A : Battery can explode if something goes wrong (internal short etc), so i wont have it anywhere near where people is/live could be often. B:  Need to be signed of by fire department, and I doubt they will let that pass...

 

you would probably need only about 10mm2 cable for 32A installation 4kw.  My cables is 20m long and cost R2k .. So stick ouside in a fireproof hokkie with the fire cutoff switch as per firepeople is my recomendation

[Frosty]

Quick question on health and safety while scoping out my Grid-tied solution:

 

I am working on the assumption that my inverter and Pylontech LIFEPO4 battery be located close to each other to reduce cable lengths for low voltage cables.

 

I have a convenient location for our Inverter+Battery next to the main DB. But it is located in a general living area. Is that OK?

 

Or should I rather locate it all in the outside building. This will result in longer 220V cables to be run to the inverter and then back again to the DB, so somewhat of a cost penalty.

The fan on the inverter can get quite loud for a living area. Mine is in the garage, so not a problem to have it right at the DB.

 

Another friend who has virtually the same setup, has his on the diagonally opposite wall in the garage, i.e. about 8.5m apart. No problems. What is on the other side of the living “room” wall?

[Vetplant]

The fan on the inverter can get quite loud for a living area. Mine is in the garage, so not a problem to have it right at the DB.

 

Another friend who has virtually the same setup, has his on the diagonally opposite wall in the garage, i.e. about 8.5m apart. No problems. What is on the other side of the living “room” wall?

The DB isn't in what I will call our main living room, it is an additional room that is not used frequently, but is next to the main living area. So I am hoping the noise isn't too bad.

 

Otherwise I will mount it in the external building and make peace with the additional wiring cost.

[Vetplant]

1: Make sure inverter is on the Eskom approved list. Otherwise you will have to pay to get it approved or add another R12k unit to get it passed

 

2: A : Battery can explode if something goes wrong (internal short etc), so i wont have it anywhere near where people is/live could be often. B: Need to be signed of by fire department, and I doubt they will let that pass...

 

you would probably need only about 10mm2 cable for 32A installation 4kw. My cables is 20m long and cost R2k .. So stick ouside in a fireproof hokkie with the fire cutoff switch as per firepeople is my recomendation

1. First I have heard of this requirement, where can I check the list? I have my eye on the Kodak VMIII 5KW paired with a Pylontech 2.4kWh LIFEPO4 battery pack, would this be cleared by Eskom?

 

2. Also never heard of the Fire Department thing, is that a municipality specific bylaw? I wonder if it applies to Tshwane? I know of the Electrical CoC for insurance purposes and if you want to sell it one day, so I was planning to have that done regardless.

 

The battery explosion risk is something I wonder about, I might just mount it externally just for the peace of mind aspect.

 

I see some inverters are rated to be mounted outdoors, as longs as it sits underneath a roof overhang. I presume that the LIFEPO4 batteries are also happy with that mounting. Especially in Pretoria, where we have way less moisture than the cities on the coast.

[Frosty]

I checked with my local bylaws and there no mention of any pre-approval. It could be in the Western Cape where they allow feedback into the grid.

 

If your system is installed by a certified electrician, and he signs a CoC, it is for the whole house and not just the installation, then you should be okay.

[Vetplant]

I checked with my local bylaws and there no mention of any pre-approval. It could be in the Western Cape where they allow feedback into the grid.

 

If your system is installed by a certified electrician, and he signs a CoC, it is for the whole house and not just the installation, then you should be okay.

Yep, I roped in my trusty local Electrician. He agreed to do a CoC for the whole house after the installation. So all risks covered methinks...

[Frosty]

Yep, I roped in my trusty local Electrician. He agreed to do a CoC for the whole house after the installation. So all risks covered methinks...

A certified electrician worth his weight won't give a CoC for a part installation - anyone who does, I will stay away from.