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The Electric Revolution

Dabop said:
Unfortunately most current hybrids on the market DO allow users access to some settings that could lead to system damage (like battery charge current levels), max charge and discharge levels and yes, grid export levels on some.... (looking at you EG4 and Frontius....) and with no warnings during setup (all manufacturers assume (and we all know the saying about that) that the person programming it actually knows what they are doing... we already know that is not the case.. which is why I would prefer to see the settings be a 'restricted menu'...) EVERY setting can cause system damage if improperly set- some in the short term, some may take longer... and we STILL don't know exactly what this setting is that she was fooling with to 'reduce clipping' was...

She is pushing her batteries far harder than LFP should be (down to 10%!!!- they can 'handle' it, but a discharge that deep will be seriously reducing the battery service life- by anything up to half of what it could be- most manufacturers recommend 20% at MOST, 30% for a long service life... plus trotting out the 'don't keep them at 100%' nonsense- that applies SPECIFICALLY to one form of lithium cell (NCM) which is rapidly disappearing from both the EV and Powerwall markets, LFP is a completely different chemistry of lithium cell, and can be held at 100% without issue (NCM is the cells found in mostly 'some' Tesla products these days or stuff from very early in the hybrid markets being popular, LFP isn't quite as good in the energy/kg stakes, but it can accept higher charge/discharge currents, requires less thermal management than NCM (the 'burny burny ones) and also has a significantly better service life than NCM... (unmanaged NCM cells are usually around 2000 charge cycles at best, ones with active cooling might get up around 3000 charge cycles, LFP is usually quoted as 3000-5000, and the LYP like I am using is even better again (at the expense of being slightly larger/heavier than LFP) having a service life of 5000-7000 charge cycles, AND a service temperature range far better than LFP, NCM or L/A (-45C up to 85C!!!) although they are slightly more expensive than LFP, their added service life and temperature tolerance is much better for high temp areas like mine where L/A and LFP both need charge tapering in summer or risk premature failure... (pushing high currents into a LFP above 40C can effectively halve the service life again!!!)
Click to expand...

Points about battery health are quite separate from all the garbage you have been spouting about dangerous practices and illegal practices and DNO inspectors. You didn't start by warning me that I might be damaging my battery, you started by claiming that I was doing things that are illegal and dangerous. You haven't substantiated that at all and now you're just sidestepping it.

You claim not to know what settings I'm using even after I've explained it and even posted a graph. That again doesn't fill me with confidence that you really understand what you're talking about behind all the Gish Gallop of technicalities. What am I doing that you think is illegal? What am I doing that you think is dangerous?

You've now shifted your focus away from your original criticism of my summer manoeuvre to capture the clipping (which doesn't involve deep discharge of the battery, simply discharging it to 30% at the lowest and letting it pick up charge - usually to no more than 70-80% - quite slowly during the day) to my daily cycling of the battery to take advantage of the difference between the import and export tariffs. A completely separate issue.

I haven't changed any of the settings you keep going on about. Your opinion that discharging the battery then charging it again some minutes later is noted, but if that had come as a friendly warning at the start rather than emerging from a bad-tempered rant (which seems to be entirely misconcieved) about a completely separate issue I might have been inclined to give it more weight.

I run a car with an LFP battery and I have been keeping up with the latest advice. That advice is indeed not to leave the thing sitting at 100% for days and weeks on end.

Forgive me, but your almost hysterical performance in this thread has not filled me with confidence that you are a serious expert whose advice is worth considering, rather than a former journeyman who is now out of touch and grumpy with it.
 
acbytesla said:

insideevs.com

Science Says Hard Acceleration Might Be Good For Your EV Battery

A new study has found that the occasional spirited acceleration in an EV is actually good for its long-term battery health.
insideevs.com insideevs.com
Click to expand...

Interesting. I had read the same thing. They don't seem to mention which battery chemistry they're talking about though. Also, 85% SOH being regarded as end of life seems a bit pessimistic. A car that started with 300 miles of range which now has only 255 miles of range is hardly useless.
 
Rolfe said:
Interesting. I had read the same thing. They don't seem to mention which battery chemistry they're talking about though. Also, 85% SOH being regarded as end of life seems a bit pessimistic. A car that started with 300 miles of range which now has only 255 miles of range is hardly useless.
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No, it doesn't seem to differentiate between LP and LMC.

The researchers used the battery's State of Health (SOH) to measure how a cell degrades over time. The study concluded that a cell reaches End of Life (EOL) at 85%. Now, that's not because it's unusable, but because it's officially aged out of its top-tier performance. Think of it like the battery equivalent of peaking in high school. And once the battery reaches that 85% SOH, the researchers will count the number of Equivalent Full Cycles (EFCs)—that's the number of times it fully cycled from 0% to 100%. The more EFCs, the better a battery performs over its lifespan.
 
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Remember rule 12. The topic is the Electric Revolution not the other posters and their understanding and competence.




Replying to this modbox in thread will be off topic  Posted By: jimbob
 
What does % charge even mean for a battery system for the % charge of the cells used in it? The manufacturer of the battery system decides what constitutes 0% and 100% charge, as well as the maximum rate of charge and discharge.
 
Ivor the Engineer said:
What does % charge even mean for a battery system for the % charge of the cells used in it? The manufacturer of the battery system decides what constitutes 0% and 100% charge, as well as the maximum rate of charge and discharge.
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Sorta...

The chemistry actually sets the '100%' and '0%' marks (some manufacturers may give 'conservative' figures for their cells but it always comes back to the specific chemistry of the cell in question... (my LYP is similar, but not quite identical to the more common LFP- the Yttrium doping does slightly change its voltages)

Maximum charge and discharge rates again depend on the actual chemistry (as well as capacity (Ah/kWh) also being a factor)- the most important figure in determining the max current is the internal resistance of the cells themselves- a cell with a lower internal resistance can handle more current than one with a higher internal resistance... the manufacturer knows what the exact value is and uses it to set their battery/cell limits... (Most LFP are 1CA or less with some being 2CA, where my LYP are 3CA- so my 400Ah LYP with a 3CA are 1200A, but a 400Ah LFP with a 1CA limit is only 400A- which is why looking at ALL the specs is important when selecting cells/batteries (there is a difference lol) as what may be suitable in one application may not be in another...

For example- a 48v nominal 400Ah battery bank (16 series LFP/LYP cells) is a nominal 20kWh of storage- but the LYP system can handle much larger surge currents than the LFP (approx 57kW limit on LYP against only 19kW on LFP- my 12kw inverter for example can output a surge of 3x the constant output wattage for up to 20 seconds (so 36kW for 20 seconds)- on my LYP thats not an issue, on a LFP battery bank with a 1CA limit- well every time that inverter goes into its surge output limit- its doing irreversible and permanent damage to the LFP battery bank.... as its maximum output is limited to only 19kW and its effectively being taken to double that for up to 20 seconds...

That may not initially cause issues, but it WILL be slashing its service life dramatically...
(obviously a hybrid inverter like mine doesn't know what it is going to be coupled with, so one of its menu limits available is current limiting- which when set to the appropriate level, means a LFP battery bank can be used, set to a higher level allows a LYP set like mine to be used- that will 'appear' to be 'clipping' the output (well it is lol- because thats what we want- to save the much more expensive battery pack) but if 'randomly played with' with- well it most certainly will get rid of that 'artificial clipping'- but with the result the service life of that LFP battery pack is going to be SLASHED to a fraction of what it could have been.....

A professional will have the datasheets for the battery pack and know exactly what its current limit 'SHOULD' be, and set the inverter to those limits...
 
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Dabop said:
Sorta...
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There's very little to no sorta about it in the UK. The particular lithium chemistry of the cells used in a battery system will have limits and trade-offs. The designer of the battery system will include circuitry to make sure these limits are not exceeded and decide on what trade-offs to make, such as longevity vs. maximum charge, maximum charge and discharge rate and maximum depth of discharge of the cells. E.g., 100% charge of the battery system could correspond to 90% charge of the cells. 0% charge of the battery system could correspond to 20% charge of the cells. There will also be circuitry to bypass individual or small groups of cells in the battery pack that are charged or discharged. The obvious place to put this management circuitry is in the same box as the cells, giving the battery manufacturer confidence to specify a particular performance and warranty period. That describes the vast majority of home batteries sold in the UK.

Installing a high energy battery system less fool proof than this in a UK home would likely invalidate any insurance and leave the installer open to being sued and/or prosecuted.
 
Dabop said:
A professional will have the datasheets for the battery pack and know exactly what its current limit 'SHOULD' be, and set the inverter to those limits...
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Well, y'know, since my inverter was set up by a professional, and I haven't changed any of the settings, maybe this is all entirely academic?

There are two issues here. First there is the question of harvesting the "clipping", which is what set Dabop off into such a tizzy. All I'm doing as regards that is arranging the system so that there is capacity in the battery at the point where the solar generation exceeds the export limit. This is an integral property of the system, one which I noticed very soon after I got the system. The battery got to 100% one morning on the solar alone, and once it had reached that point the system clipped the solar output to keep the export below the export limit. All one has to do to exploit this is to export the battery down to say 30% early in the morning and then hold it there by setting the inverter to "export to 100%". This simply prevents the battery from charging from the solar generation until the export limit has been reached, and then the excess solar, instead of being clipped, goes into the battery. Set the end of the "export to 100%" slot to a time before the solar has faded so low that it can't support the house load any more, and that's it. There's nothing complicated about it, and it requires no interference with the way the inverter is set up. It also doesn't put any particular stress on the battery, merely exporting to 30% at the lowest, and letting the battery pick up charge slowly during the day to get to maybe 70-80%.

I am yet to fathom what's supposed to be either illegal or dangerous about this.

The other issue is the evening export of the battery down to the minimum the system will allow (which seems to be set at 5%, I have not changed that) for 15p/unit, followed about half an hour later by charging it up to 100% from the grid at 7p/unit. I did consider the effect of this on battery life when I decided to do it, but I have reasonable confidence in the longevity of a properly-installed LFP battery to cope with this. Practically everybody with an export tariff does this, it's a normal setting, and the forums and chat groups are not filled with people warning that this is going to SLASH its service life to "a fraction" of what it could have been.
 
Ivor the Engineer said:
There's very little to no sorta about it in the UK. The particular lithium chemistry of the cells used in a battery system will have limits and trade-offs. The designer of the battery system will include circuitry to make sure these limits are not exceeded and decide on what trade-offs to make, such as longevity vs. maximum charge, maximum charge and discharge rate and maximum depth of discharge of the cells. E.g., 100% charge of the battery system could correspond to 90% charge of the cells. 0% charge of the battery system could correspond to 20% charge of the cells. There will also be circuitry to bypass individual or small groups of cells in the battery pack that are charged or discharged. The obvious place to put this management circuitry is in the same box as the cells, giving the battery manufacturer confidence to specify a particular performance and warranty period. That describes the vast majority of home batteries sold in the UK.

Installing a high energy battery system less fool proof than this in a UK home would likely invalidate any insurance and leave the installer open to being sued and/or prosecuted.
Click to expand...

Exactly. The system is set up by a professional and the user is given settings to play with that don't interfere with these professional settings. I have every confidence in my installer, and he said OK here you are, now play with the settings to find what works best for you. He has seen the settings I am using and has never said, oh best not to that, it might SLASH the service life of your battery to a fraction of what it could have been! Neither has he said, don't do that because it's illegal and the DNO inspector will have your guts for garters. Neither has he said don't do that because it's dangerous and the whole thing might burst into flames or electrocute the cat.

This is a complete storm in a teacup. The battery has inbuilt protections, and while certain behaviours might be somewhat less optimal for longevity than others, as far as I can see it's all pretty marginal, and even if the battery is down to 85% of its original capacity in 10 years time (which I think is really pessimistic), that will still be plenty for my purposes.
 
Ivor the Engineer said:
There's very little to no sorta about it in the UK. The particular lithium chemistry of the cells used in a battery system will have limits and trade-offs. The designer of the battery system will include circuitry to make sure these limits are not exceeded and decide on what trade-offs to make, such as longevity vs. maximum charge, maximum charge and discharge rate and maximum depth of discharge of the cells. E.g., 100% charge of the battery system could correspond to 90% charge of the cells. 0% charge of the battery system could correspond to 20% charge of the cells. There will also be circuitry to bypass individual or small groups of cells in the battery pack that are charged or discharged. The obvious place to put this management circuitry is in the same box as the cells, giving the battery manufacturer confidence to specify a particular performance and warranty period. That describes the vast majority of home batteries sold in the UK.

Installing a high energy battery system less fool proof than this in a UK home would likely invalidate any insurance and leave the installer open to being sued and/or prosecuted.
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LOL- yet the UK uses the exact same hybrid inverters we do in Australia (and indeed most of the world- hell even the yanks use some of them...)

This shows why you have trained professionals that do the system design- because they already know that there is no such thing as a singular 'system'- the same system that will be perfect for one install will be grossly inadequate for another, and massively oversized for a third- which is why modular battery systems have become the norm for many newer installs- the person designing the system for THAT install will do a energy audit- before deciding on various factors like the inverter wattage needed to supply the existing loads, what wattage is allowable for export (if any at all), the storage capacity of the battery storage needed- and after deciding what equipment is suitable , install and commission it- including setting the inverters configuration menu up...

This for example is a typical modern UK install- with the battery storage can be expanded to the size required, simply by adding 'more drawers' (this is an Ecoflo system installed in the UK- 15kwh of storage (3 5kwh 'battery boxes' stacked), and the inverter programmed to allow the acceptable charge current for that configuration done...
1761058261971.png
1761057695761.png1761057712265.png
And finally the inverter goes on top...
1761057742499.png
1761058437640.png
(That is a UK sparkie I have been following for years named Nick Bundy doing that install lol- in the UK obviously....)


And yes- I know all about BMS's (thats the name of your "There will also be circuitry to bypass individual or small groups of cells in the battery pack that are charged or discharged. The obvious place to put this management circuitry is in the same box as the cells" circuits- BMS or Battery Management System....

(oh and apart from 'obsolete' Tesla powerwalls- nobody does the multiple parallel cells' system anymore- they all use a single series string of prismatic cells...)
:boggled:
And ironically- BMS's ALSO are programmable lol (thankfully they mostly need 'installers software' to 'fiddle with the settings' which stops the uneducated fiddling and setting fire to their battery banks lol.... (Daly and Ant are the two largest sellers of BMS's currently...)
 
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Maybe because the export tariffs in Australia are so pathetic, and so there is no incentive for a householder to arbitrage electricity by charging up for 7p then exporting for 15p, an Australian installer doesn't realise this is common behaviour? Or that systems are set up on the assumption that this will happen?
 
Rolfe said:
Maybe because the export tariffs in Australia are so pathetic, and so there is no incentive for a householder to arbitrage electricity by charging up for 7p then exporting for 15p, an Australian installer doesn't realise this is common behaviour? Or that systems are set up on the assumption that this will happen?
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This is also what the grid wants to help balance the load over the day: charge up batteries overnight and then use the energy during the day when the really big energy users come online.

Economy 7 for storage heaters was a similar principle. If the internet was around then there'd be some bloke mansplaining how you've set the dial wrong and you should leave it to the professionals, love!
 
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On a smaller scale, but with the same possible consequences a man converted an older electric riding mower from lead-acid batteries to a lithium based battery bank.

This required changing the charging system and a bit of fiddling with the battery to control systems to add protection for the amperage difference. It's a bit beyond me what he did besides add breakers but it wasn't a direct battery change.

This is serious stuff where uncontrollable fires are possible. Takes a bit more than shadetree mechanics now.
 
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8enotto said:
On a smaller scale, but with the same possible consequences a man converted an older electric riding mower from lead-acid batteries to a lithium based battery bank.

This required changing the charging system and a bit of fiddling with the battery to control systems to add protection for the amperage difference. It's a bit beyond me what he did besides add breakers but it wasn't a direct battery change.

This is serious stuff where uncontrollable fires are possible. Takes a bit more than shadetree mechanics now.
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So perhaps you would be good enough to explain to me what it is that I'm doing that has the potential to cause "uncontrollable fires".
 
Ivor the Engineer said:
This is also what the grid wants to help balance the load over the day: charge up batteries overnight and then use the energy during the day when the really big energy users come online.

Economy 7 for storage heaters was a similar principle. If the internet was around then there'd be some bloke mansplaining how you've set the dial wrong and you should leave it to the professionals, love!
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It's why they're happy to take all the solar I want to sell to them during the day, and pay over twice the night-time tariff for it. I realise now that I lost out on an incentive to export my battery earlier in the day during last winter, because I didn't understand how the offer affected people with solar and batteries. I do now, so if they go there again this winter I'll export as much as I can during the hour when the offer is in force, which will still leave me plenty to be going on with.
 
8enotto said:
On a smaller scale, but with the same possible consequences a man converted an older electric riding mower from lead-acid batteries to a lithium based battery bank.

This required changing the charging system and a bit of fiddling with the battery to control systems to add protection for the amperage difference. It's a bit beyond me what he did besides add breakers but it wasn't a direct battery change.

This is serious stuff where uncontrollable fires are possible. Takes a bit more than shadetree mechanics now.
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Actually- LFP (and LYP) can actually be used as a 'straight drop in' replacement for L/A...
It's done regularly in 4wds for their 'house battery' for running the fridge etc....
No need for any changes whatsoever to the charging system...
There are literally tens of thousands (if not more) of these exact batteries in use Australia wide lol (in fact the system I was working on today has 6 of that exact same brand, but the 300Ah version)
1761067372938.png

(you are thinking of the older NMC lithiums which were notorious for catching fire commonly found in some US made EV's (cough Tesla), and powertools and the like, while LFP (also known as LiFePO4) are far more stable and extremely unlikely to go into thermal runaway (ie catching fire), and LYP (LiFeYPO4) are practically impossible to get go into thermal runaway at all....

This is the exact same brand I use on my own offgrid home lol- less than 4 mins long, dont watch if extreme battery abuse upsets you lol....
https://www.facebook.com/video.php?v=448765589386733

Like far from the 'catches fire at the drop of a hat, a LYP can be abused to extremes and still just sits there....
1761066936195.png
That's the 'lil brother' 40Ah version of my 400Ah ones...
1761067019298.png
 
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Ivor the Engineer said:
This is also what the grid wants to help balance the load over the day: charge up batteries overnight and then use the energy during the day when the really big energy users come online.

Economy 7 for storage heaters was a similar principle. If the internet was around then there'd be some bloke mansplaining how you've set the dial wrong and you should leave it to the professionals, love!
Click to expand...
Edited by Agatha: 
Do not refer to your ignore list, however obliquely.


And overnight offpeak tariffs were introduced to INCREASE nighttime consumption- this was because baseload thermal plants have a very narrow band of fuel efficiency- if the load gets too small, their fuel consumption rises rapidly.... and they struggle to change their output rapidly...

So 'cheap' offpeak rates were introduced to try and get people to INCREASE their nighttime electricity consumption- because that pushed the fuel economy back into the 'cheap to feed it' band.... (or worse, having to shut a plant down entirely... a difficult and expensive thing to do, avoided at all costs...)

Its also why the outright lying coming from some electricity suppliers is so annoying- widespread rooftop residential solar in Australia has not only cut the need for SEVEN new baseload plants, but has actually allowed several older coal fired plants to be closed early to boot....

If we didn't have that residential rooftop solar here, we would need over 20GW of new generators in place (BIG $$$$) and worse- unless they were gas fired (quick ramp up and ramp down, but cost more than thermal coal plants to run) they would make the overnight glut of electricity even WORSE....
 
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Rolfe said:
So perhaps you would be good enough to explain to me what it is that I'm doing that has the potential to cause "uncontrollable fires".
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I do not know what you are doing. I wasn't even aware of how a home solar system was controlled before reading this thread. But I did learn something from it. Now I want one more.

I am only aware that a bit of research is required when modifying battery bank systems. Or an expert in my case.

Maybe whatever you did is OK if no problems?

Either way stop feeling attacked by everything. It's unbecoming.
 
Dabop said:
Actually- LFP (and LYP) can actually be used as a 'straight drop in' replacement for L/A...
It's done regularly in 4wds for their 'house battery' for running the fridge etc....
No need for any changes whatsoever to the charging system...
There are literally tens of thousands (if not more) of these exact batteries in use Australia wide lol (in fact the system I was working on today has 6 of that exact same brand, but the 300Ah version)
View attachment 64992

(you are thinking of the older NMC lithiums which were notorious for catching fire commonly found in some US made EV's (cough Tesla), and powertools and the like, while LFP (also known as LiFePO4) are far more stable and extremely unlikely to go into thermal runaway (ie catching fire), and LYP (LiFeYPO4) are practically impossible to get go into thermal runaway at all....

This is the exact same brand I use on my own offgrid home lol- less than 4 mins long, dont watch if extreme battery abuse upsets you lol....
https://www.facebook.com/video.php?v=448765589386733

Like far from the 'catches fire at the drop of a hat, a LYP can be abused to extremes and still just sits there....
View attachment 64990
That's the 'lil brother' 40Ah version of my 400Ah ones...
View attachment 64991
Click to expand...

I only watched a video and followed the steps the creator made to convert it over. He didn't state exactly what battery but they were cheaper types. It was a budget project.

But, thanks for the information on what can be a drop in replacement. I hope to be able to use it when possible. Our grid here is poor to crap even after updates by the city and we could use a home battery backup system.
We are looking into costs actually.
 
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