Generator or Inverter for residential use?

wingnut771

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Yeah it's the 4.8 one here:

My guess is they save money on some of the components inside so I'd expect the battery cells to outlast the battery management components if all goes well.

It's one of the reasons I'll probably shut it down when not using, it's basically a permanent fixture now so I'd aim for decades and not years of use (assuming of course it's not ever going to be used for PV, which it might).
i've always thought it's heavier on electronics to switch it off and on again compared to leaving it on (like a pc), as the components remain at a constant temperature instead of cooling down and warming up (expanding and contracting).
 

RaptorSA

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i've always thought it's heavier on electronics to switch it off and on again compared to leaving it on (like a pc), as the components remain at a constant temperature instead of cooling down and warming up (expanding and contracting).
Yeah but that's more of a blanket statement than of any real value in the real-world given other possible factors.
Also, I don't think the "rough" circuitry inside of a battery or inverter can be easily compared with the tight tolerances you find on something like a PC motherboard when it comes to expansion and contraction over time.

Let me give you an example that applies to me:
I've been living in this place for 12 years now, and one of the things I've learned in the most hands on type of ways is that because we don't have extractor fans in our units, there's a ton of smoke and fine oil particles that accumulate on unreachable surfaces over time whenever you cook something on the stove... I guarantee you if I left that inverter running for 2 or 3 years it'll be loaded with gross sticky dust on the inside for no good reason.
 

wingnut771

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Yeah but that's more of a blanket statement than of any real value in the real-world given other possible factors.
Also, I don't think the "rough" circuitry inside of a battery or inverter can be easily compared with the tight tolerances you find on something like a PC motherboard when it comes to expansion and contraction over time.

Let me give you an example that applies to me:
I've been living in this place for 12 years now, and one of the things I've learned in the most hands on type of ways is that because we don't have extractor fans in our units, there's a ton of smoke and fine oil particles that accumulate on unreachable surfaces over time whenever you cook something on the stove... I guarantee you if I left that inverter running for 2 or 3 years it'll be loaded with gross sticky dust on the inside for no good reason.
put some decent washable filters and fans on that cabinet you want to build. :laugh:
 
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thechamp

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Good to see that some of us are not sleeping on the job with this temporary loadshedding reprieve, I am still hoping for lower prices on inverters and batteries due to low demand.
 

RaptorSA

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Good to see that some of us are not sleeping on the job with this temporary loadshedding reprieve, I am still hoping for lower prices on inverters and batteries due to low demand.
The problem is though, now that RaptorSA has finally installed his system after all the moaning we'll probably never see loadshedding again...
You can all thank me later :laugh:
 

Grouter

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I just spent R5300 on another 2 x 105ah lead calcium batteries for my little Mecer 2400 inverter to add to the existing 2 in order to extend my runtime. The shedding is coming people.
 

RaptorSA

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I just spent R5300 on another 2 x 105ah lead calcium batteries for my little Mecer 2400 inverter to add to the existing 2 in order to extend my runtime. The shedding is coming people.
Thing is, my family in Mpumalanga is already experiencing load-shedding each day like clockwork, and yet not a peep in the media.

Agreed, it's coming and the more government insists it'll be a non-issue this winter the worse I'm expecting it to be.
Their so-called "models" changes f-all about the slow unstoppable march of entropy that's been going on, we've all seen this before, the entire thing can go to sh*t in mere hours.
 

Pho3nix

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My budget was R50K but with equipment at R46K plus another R10.5K for install I went slightly over.
A similar system with two cool but butt ugly Pylon batteries would have been closer to R90-100K with install.

I'll PM you the guy/company I used if you're interested (Ranburg/Roodepoort region).

It was their first Lithium install but they were bloody excellent at support and I'd gladly pay it again if I could.

I almost tried the install myself at some point but that would have been a really dumb idea, you really need to know what you're doing (at least I can say I was the one who figured out the battery comms issue :))
Will PM you in a couple of months. Still saving for parts
 

RaptorSA

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Will PM you in a couple of months. Still saving for parts
Good luck man.
I hope what's happening in this country doesn't screw you over when the time comes, it's still definitely worth saving up for even though you don't always need it. I always remind myself of that blind rage I've felt so many times now when everything goes dark and I'm stuck staring at a black ceiling in my room, in bed, at 7PM... F**k that s**t.
 

RaptorSA

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Finally got my setup installed yesterday and today after having to watch it all lie on the ground during the lockdown.
Had some major issues initially but managed to figure it out (ended up using a CAT5 cable to get the BMS to communicate with the battery properly, that resolved any inverter errors).

It's in a 82 square two-bedroom unit next to my kitchen, so I'll probably spend some time in future repainting some of the walls and trunking and maybe mounting a white 250mm pine panel left of it so you don't have to look at the black side view when you walk into the unit and so it blends with the panel room dividers for the living room/home theatre... might even build a "corner closet" of sorts around it since airflow isn't an issue and the place is always a few degrees colder than the surface of Mars.

Noise wise that Growatt inverter is a bit of a hoover like some have mentioned but for now I kind of enjoy the sound since it's like an additional "sense" when running high power consumption devices, no heaters and kettles and it's quiet enough for my taste.

When I've been running it for some time and did all the testing I wanted to do, I'll flip the DB board to mains power mode only and spare the fans, electronics etc. I'll just boot it up every now and again so the battery can charge if it needs to... but we'll see how it goes.

It's a lot of fun to finally be able to run around like an idiot and switch devices on and off to get an idea of what your actual usage is, no more crap spreadsheet calculations based on guesses.

Currently, with most of my lights + LED strip lights on, the WiFi router, fibre router, 55" TV, 2 Xiaomi Android TV devices, network switches and soundbar I'm only using around 250-300 Watts if I don't use the fridge...
Switching out the TV for the projector and 6.2 surround sound speakers get me to about 400 Watts, which is pretty decent I think. My goal was to not go over 500 Watts.. with 400 Watts the max I'd use... funny how my actual usage was in that range all this time.

No idea how long it'll last me, but I have a feeling if I don't use the fridge or unnecessary lights and appliances it might for be for days. That pack has a lot of energy in it for one person... but hey, f**k you Eskom.

View attachment 844601 View attachment 844605
View attachment 844613
OK, update time:
Since 4.8kWh Lithium systems seem more common these days I thought I'd share my first "battery & inverter burn-in stability" test to see what she's capable of and so that anyone else can get an idea of what they're getting into if they buy a similar-sized lithium phosphate system.

My philosophy was simple:
Leave everything as it is during a normal Saturday afternoon, then drop the mains power and double down on usage by watching 3 hours of Youtube on the projector and doing whatever else I can do with the extra time, Desktop PC internet browsing while listening to music etc. in this case.

...then stop the test the moment I reach 50% and see how much time I managed to get.
Obviously this is an extreme case, but that's the whole point (entertaining load-shedding stranded friends or whatever in the worst case).

Why stop at 50% if the depth-of-discharge is 80% default on Lithiums?
Well I know it's not flooded batteries but in real life, if there's load-shedding or an outage I'd assume it's at about the 50% mark where I'd mentally start to get antsy and plan for the worst by lowering unnecessary consumption due to only 30% drainage remaining. I try to treat it like my bank account, assume there's less available so you don't get stranded when the worst happens.
I don't think I'll ever go down to 20% if I can help it.

I made sure I had the projector, PC etc. running already when dropping the mains to make sure failover doesn't cause any issues, I didn't notice it as expected, 10+ milliseconds is enough.

Here's a summary of the kind of devices I used and how often:

Always On:
ApplianceRated Wattage
Whirlpool Fridge 220 Litres (20+ years old)Stats not available (+-130W?)
2m Kitchen LED strip20W
4 Philips Hue (white) Kitchen LEDs - 20% Brightness5W
2m Philips Hue strip light20.5W
1 or 2 Philips Hue Living Room lights+-10W
Ezviz C3W Security Camera6W Max
Asus DSL-AC52U WiFi Router18W Max
Generic Fibre CPE Router10-20W?
2 x TP-Link Gigabit Switches3-5W Max
Xiaomi Mi Android TV Box<10W

Partially idling/standby or used once or more:
Appliance/DeviceRated Wattage
3000 Lumen Optoma HD143X DLP Projector - Max Brightness (On for 3 hours)300W (330W Max)
Sony HT-DDW1500 MU.TE.KI 6.2 Surround (on for 3 hours)80W
Desktop PC - Intel i7 3770 (2.5 Hours idle, browsing etc. for 1.5 Hours, no GPU gaming loads)Not sure (150-250W?)
PC Monitors 32" & 27" both @ 1440p (same as PC)36W + 44W
3 Office LEDs (on when using PC)20W
2 Bedroom LEDs10W
Google Home speaker (music on low for a few mins)33W Max
Boiling Kettle +-400ml water (used once)2000W
CFL Bathroom light (few Nr1's & Nr2)13-15W
Dash Charging OnePlus 5T phone from 68% to 92%20W

Usage and SOC charts:
1590261243530.png
1590261046556.png

So how long did I get?
Exactly 4 hours to get to 50%

1590261377704.png


One thing to note: Not sure how to explain this but the inverter was whisper quiet (except when the kettle was going). Felt like it was almost quieter than when it's in bypass mode or whatever. Weird.

Clearly this is no panacea so you'd still have to be pretty much on top of your usage if you wanted to get through a full day's work and still have some energy left over at night for TV etc...

Charging:
This is the recharge time. It's on the default setting of 0.1C or 0.2C so way below what's possible. I also used my oil heater while it was dumping energy into the battery to see if the breakers could take it. No issues.

Basically, charging was at twice the rate of depletion, so took 2 hours to refill.

1590306732803.png
 
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thechamp

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OK, update time:
Since 4,.8kWh is common these days I thought I'd share my first "battery & inverter burn-in stability" test to see what she's capable of and so that anyone else can get an idea of what they're getting into if they buy a similar-sized lithium phosphate system.
It's been running on passthrough for two days since I apparently fixed the screw up with the inverter and battery not chatting so this was a good time to start playing.

My philosophy was simple:
Leave everything as it is during a normal Saturday afternoon, then drop the mains and double down on usage by watching 3 hours of Youtube on the projector and doing whatever else I can do with the extra time, PC browsing while listening to music etc. in this case.

...then stop the test the moment I reach 50% and see how much time I managed to get.
Obviously this is an extreme case, but that's the whole point (entertaining load-shedding stranded friends or whatever in the worst case).

Why 50%?
Well I know it's not lead-acid but in real life, if there's load-shedding or an outage I'd assume it's at about the 50% mark where I'd mentally start to get antsy and plan for the worst by lowering unnecessary consumption due to only 30% drainage remaining. Don't think I'll ever go down to 20% if I can help it.

I made sure I had the projector, PC etc. running already when dropping the mains to make sure failover doesn't cause any issues, didn't notice it as expected, 10+ milliseconds is enough.

Here's a summary of the kind of devices I used and how often:

Always On:
Fridge (20+ years old and smallish)
2m Kitchen LED strip
4 Philips Hue (white) Kitchen LEDs - 20% Brightness
2m Philips Hue strip light
1 or 2 Philips Hue Living Room lights
Ezviz C3 Security Camera
Asus DSL-AC52U WiFi Router
Generic Fibre CPE Router
2 x TP-Link Gigabit Switches
Xiaomi Mi Box

Partially idling/standby or used once or more:
3000 Lumen Optoma Projector - Max Brightness (On for 3 hours)
Sony 6.2 Surround (old power-hungry DDW1500 system - on for 3 hours)
Desktop PC (2.5 Hours idle, browsing etc. rest of the time, no GPU gaming loads)
PC Monitors 32" & 27" both @ 1440p (same as PC of course)
3 Office LEDs (on when using PC)
2 Bedroom LEDs
Google Home speaker (music for a few mins)
1 X Boiling Kettle +-400ml water (Ouch! Stands out like a sore thumb on that graph)
CFL Bathroom light (few Nr1's & Nr2)
Dash Charging OnePlus 5T phone from 68% to 92%

And here's the charts:
View attachment 844971
View attachment 844967

So how long did I get?
Exactly 4 hours to get to 50%

View attachment 844973


One thing to note: Not sure how to explain this but the inverter was whisper quiet (except when the kettle was going). Felt like it was almost quieter than when it's in bypass mode or whatever. Weird.

Clearly this is no panacea so you'd still have to be pretty much on top of your usage if you wanted to get through a full day's work and still have some energy left over at night for TV etc...

I'll do another test this week to see what I get during a workday on the desktop and when switching off the fridge etc.
I'll also update this post later once the battery is charged, it's going quite quickly and that's only at 0.1C (or 0.2C?)
4 hours to 50% is super decent with all the connected load, plus the kettle. What is the manufacturer claimed DoD?
 

RaptorSA

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4 hours to 50% is super decent with all the connected load, plus the kettle. What is the manufacturer claimed DoD?
The DoD is the usual lithium 80% default.
So yeah if I drained it to 20% cutoff with unneccesarily high load I should get at least 6 hours.

My aim would be 12hours for those unexpected days where the substation trips when eskom comes back on. Should be attainable.
 

RaptorSA

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This is the recharge time. It's on the default setting of 0.1C or 0.2C so way below what's possible. I also used my oil heater while it was dumping energy into the battery to see if the breakers could take it. No issues.

Basically, charging was at twice the rate of depletion, so took 2 hours to refill.

1590306349839.png
 

wingnut771

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This is the recharge time. It's on the default setting of 0.1C or 0.2C so way below what's possible. I also used my oil heater while it was dumping energy into the battery to see if the breakers could take it. No issues.

Basically, charging was at twice the rate of depletion, so took 2 hours to refill.

View attachment 845085
what's the max rated discharge current for that battery? worried about the kettle.
 

RaptorSA

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wingnut771

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Will PM you the quick whitepaper I wrote on my findings
It's all in there.

EDIT: Nevermind @wingnut771, will dump it here.
sorry, i'm not following the logic here:
"Do note that adding photovoltaics will drastically reduce the battery lifetime due
to the way PV systems use the battery."
 

RaptorSA

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sorry, i'm not following the logic here:
"Do note that adding photovoltaics will drastically reduce the battery lifetime due
to the way PV systems use the battery."
Depends on how it's used but in many/most cases adding PV means always using the battery as the power source so if you have a PV system that can charge the pack at least once a day you're going to get a charge cycle each day if you drain the battery.... but it all depends, either way, it's lifetime will definitely be way shorter VS only using the battery during outages.
 
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