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Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 10:22 am
by Beno62
MaterialBarracuda48 wrote: ↑Sat Mar 14, 2026 10:15 am
Beno62 wrote: ↑Sat Mar 14, 2026 2:23 am
I have exactly the same issue with my Eq4800 L9. Claimed to have 41.93kwh usable storage but in reality it has 37.7kwh if you ran it down to zero %. 33.5kwh if you run it down to 10% soc.
Where did you get the kWh figures from?
My battery was at 10% soc and I charged it to 100% in a single day and the fox app quoted 33.5kwh charged for the day. Exactly 80% of 41.93kw, not the 90% that it should be. Very dodgy things going on here. Great product, dodgy specification claims. Dodgy Australian Government Rebate claims.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 10:31 am
by MaterialBarracuda48
I would not always trust the FoxCloud2.0 App too much, has too many bugs.
The Home Assistant graphs above at least told a better and more real values that could be expressed in maths terms.
I do suspect in the Australian market, there will be a class action law suit in a few years time.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 10:38 am
by evilbunny
Beno62 wrote: ↑Sat Mar 14, 2026 10:22 am
My battery was at 10% soc and I charged it to 100% in a single day and the fox app quoted 33.5kwh charged for the day. Exactly 80% of 41.93kw, not the 90% that it should be. Very dodgy things going on here. Great product, dodgy specification claims. Dodgy Australian Government Rebate claims.
Unlike lead acid batteries where voltage is a direct indication of charge, voltage in LFPs isn't, which is why people recommend doing a regular full charge, and less regularly full discharges so the electronics in the battery can better guess at how much charge there is.
Also the batteries only return a percentage of charge, the kWh's is estimated based on that.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 10:41 am
by MaterialBarracuda48
StarryTissue wrote: ↑Mon Jan 05, 2026 10:35 am
Hope that all makse sense! Again appreciate the response in trying to figure this out!
Hello again!
Just a curious question, does the
https://www.foxesscloud.com/v2/login website allow you to input minSoC/battery reserves as 0%?
Just wondering as the App is trash with some things, and you did report that you was able to set 0% but it would jump up to 10% during charge/discharge events.
Have you had any luck with contacting support to see if they can lift the limits in Australia?
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 10:41 am
by evilbunny
MaterialBarracuda48 wrote: ↑Sat Mar 14, 2026 10:31 am
I do suspect in the Australian market, there will be a class action law suit in a few years time.
On what basis?
Class action lawsuits here tend to be rare because of the ACCC.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 10:47 am
by Beno62
evilbunny wrote: ↑Sat Mar 14, 2026 10:41 am
MaterialBarracuda48 wrote: ↑Sat Mar 14, 2026 10:31 am
I do suspect in the Australian market, there will be a class action law suit in a few years time.
On what basis?
Class action lawsuits here tend to be rare because of the ACCC.
Yeah this is an ACCC thing. They will take this one seriously. It's very simple to show accurate data of this issue and I'm not the first not the last person to notice.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 10:50 am
by evilbunny
Beno62 wrote: ↑Sat Mar 14, 2026 10:47 am
Yeah this is an ACCC thing. They will take this one seriously. It's very simple to show accurate data of this issue and I'm not the first not the last person to notice.
But it's not definitive, it's just a guess by the battery. Doing certain things can improve it's guesses though.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 10:56 am
by Beno62
MaterialBarracuda48 wrote: ↑Sat Mar 14, 2026 10:41 am
StarryTissue wrote: ↑Mon Jan 05, 2026 10:35 am
Hope that all makse sense! Again appreciate the response in trying to figure this out!
Hello again!
Just a curious question, does the
https://www.foxesscloud.com/v2/login website allow you to input minSoC/battery reserves as 0%?
Just wondering as the App is trash with some things, and you did report that you was able to set 0% but it would jump up to 10% during charge/discharge events.
Have you had any luck with contacting support to see if they can lift the limits in Australia?
In Australia we can set min soc to 0% soc. But when you do set it to 0% you have access to 37.7kwh not the full 41.93kwh that we are told. I'm not wasting my time with Fox ess. The Crime and Corruption Commission can speak with them. They are committing fraud again our Federal Government.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 11:05 am
by Beno62
evilbunny wrote: ↑Sat Mar 14, 2026 10:50 am
Beno62 wrote: ↑Sat Mar 14, 2026 10:47 am
Yeah this is an ACCC thing. They will take this one seriously. It's very simple to show accurate data of this issue and I'm not the first not the last person to notice.
But it's not definitive, it's just a guess by the battery. Doing certain things can improve it's guesses though.
Yes true. But I can say that nobody with a 41.93kwh (usable) Fox ess battery in Australia will ever get 41.93kwh out of one, nor charge 41.93kwh into one no matter what they do, unless we all have a major bungled software version that can be fixed. As it stands Fox Ess are currently making false advertisement claims and are fraudulently claiming higher than legitimate rebates from the Government.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 11:21 am
by evilbunny
Beno62 wrote: ↑Sat Mar 14, 2026 11:05 am
Yes true. But I can say that nobody with a 41.93kwh (usable) Fox ess battery in Australia will ever get 41.93kwh out of one, nor charge 41.93kwh into one no matter what they do, unless we all have a major bungled software version that can be fixed. As it stands Fox Ess are currently making false advertisement claims and are fraudulently claiming higher than legitimate rebates from the Government.
Sales would probably go down if consumers were told the truth, the whole truth and nothing but the truth.
The problem isn't just with Fox ESS battery systems because there is no easy way to measure how much charge there is in LFP batteries like you can in lead acid batteries, but LABs have their own problems, like a small number of charge cycles even in deep cycle batteries compared to lithium batteries and lower energy density and higher weights.
Just like lithium batteries, LABs can under the right situation have the electrolyte split into oxygen and hydrogen and catch fire.
There is no perfect battery chemistry out there that I know of, even lithium-titanate batteries, which Wikipedia says can have up to 45,000 charge cycles (~123 years if done daily) also has a lower energy density than other lithium chemistries.
Maybe solid state lithium-ion batteries, which are supposedly finally in production, might change things, but they aren't exactly battle tested yet.
Maybe sodium-ion batteries, same stuff in table salt, will out shine lithium-ion batteries for grid purposes in future, but who can tell this early in their development.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 11:40 am
by Beno62
evilbunny wrote: ↑Sat Mar 14, 2026 11:21 am
Beno62 wrote: ↑Sat Mar 14, 2026 11:05 am
Yes true. But I can say that nobody with a 41.93kwh (usable) Fox ess battery in Australia will ever get 41.93kwh out of one, nor charge 41.93kwh into one no matter what they do, unless we all have a major bungled software version that can be fixed. As it stands Fox Ess are currently making false advertisement claims and are fraudulently claiming higher than legitimate rebates from the Government.
Sales would probably go down if consumers were told the truth, the whole truth and nothing but the truth.
The problem isn't just with Fox ESS battery systems because there is no easy way to measure how much charge there is in LFP batteries like you can in lead acid batteries, but LABs have their own problems, like a small number of charge cycles even in deep cycle batteries compared to lithium batteries and lower energy density and higher weights.
Just like lithium batteries, LABs can under the right situation have the electrolyte split into oxygen and hydrogen and catch fire.
There is no perfect battery chemistry out there that I know of, even lithium-titanate batteries, which Wikipedia says can have up to 45,000 charge cycles (~123 years if done daily) also has a lower energy density than other lithium chemistries.
Maybe solid state lithium-ion batteries, which are supposedly finally in production, might change things, but they aren't exactly battle tested yet.
Maybe sodium-ion batteries, same stuff in table salt, will out shine lithium-ion batteries for grid purposes in future, but who can tell this early in their development.
Essentially nobody in Australia has a Fox Ess battery older than 6 months. All batteries here are still brand new. I'm not talking about degradation or anything like it. The issue is we are told we have a usable capacity of X kWh but it is very clear we really can only use 0.9X kWh. It's exactly 90% of the advertised specs. Like exactly. It's not an anomaly. It's clearly Fox Ess's intention via software wether unintentionally or fraudulently I'm not sure but I don't think it's likely to be a woopsy.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 11:41 am
by evilbunny
Beno62 wrote: ↑Sat Mar 14, 2026 11:40 am
Essentially nobody in Australia has a Fox Ess battery older than 6 months. All batteries here are still brand new. I'm not talking about degradation or anything like it. The issue is we are told we have a usable capacity of X kWh but it is very clear we really can only use 0.9X kWh. It's exactly 90% of the advertised specs. Like exactly. It's not an anomaly. It's clearly Fox Ess's intention via software wether unintentionally or fraudulently I'm not sure but I don't think it's likely to be a woopsy.
I guess you missed my post about depth of discharge in Fox batteries sold in Australia, unlike global version that can only do 90%, ones sold in Australia can do 100%.
I also posted how to find out what to do to set minSoC at 0%.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 11:48 am
by Beno62
evilbunny wrote: ↑Sat Mar 14, 2026 11:41 am
Beno62 wrote: ↑Sat Mar 14, 2026 11:40 am
Essentially nobody in Australia has a Fox Ess battery older than 6 months. All batteries here are still brand new. I'm not talking about degradation or anything like it. The issue is we are told we have a usable capacity of X kWh but it is very clear we really can only use 0.9X kWh. It's exactly 90% of the advertised specs. Like exactly. It's not an anomaly. It's clearly Fox Ess's intention via software wether unintentionally or fraudulently I'm not sure but I don't think it's likely to be a woopsy.
I guess you missed my post about depth of discharge in Fox batteries sold in Australia, unlike global version that can only do 90%, ones sold in Australia can do 100%.
I also posted how to find out what to do to set minSoC at 0%.
I haven't missed anything. The issue in Australia is that if you set min soc to 0% you will have access to only 90% of the energy that Fox ess tells you on the specs sheet. That's the whole issue. They are not giving us 100% usable capacity. They are trying to make it "look" like they are, deceitfully. It's so dodgy. Someone else started this thread because they noticed. I noticed myself and then found this thread afterwards.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 11:53 am
by evilbunny
Beno62 wrote: ↑Sat Mar 14, 2026 11:48 am
I haven't missed anything. The issue in Australia is that if you set min soc to 0% you will have access to only 90% of the energy that Fox ess tells you on the specs sheet. That's the whole issue. They are not giving us 100% usable capacity. They are trying to make it "look" like they are, deceitfully. It's so dodgy. Someone else started this thread because they noticed. I noticed myself and then found this thread afterwards.
No the real issue is believing 100% isn't capable of being hit based on dodgy SoC readings.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 12:03 pm
by Beno62
evilbunny wrote: ↑Sat Mar 14, 2026 11:53 am
Beno62 wrote: ↑Sat Mar 14, 2026 11:48 am
I haven't missed anything. The issue in Australia is that if you set min soc to 0% you will have access to only 90% of the energy that Fox ess tells you on the specs sheet. That's the whole issue. They are not giving us 100% usable capacity. They are trying to make it "look" like they are, deceitfully. It's so dodgy. Someone else started this thread because they noticed. I noticed myself and then found this thread afterwards.
No the real issue is believing 100% isn't capable of being hit based on dodgy SoC readings.
Ok. You are saying you believe the BMS is tracking the soc conservatively 10% in one direct cycle each and every cycle always? That's almost just as poor as actually locking out 10% capacity intentionally and telling us they haven't. It's almost the same thing. I'd understand if it got 10% out of wack over a week but not in 3 hours since it's last full charge to 100%.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 12:04 pm
by evilbunny
Beno62 wrote: ↑Sat Mar 14, 2026 12:03 pm
Ok. You are saying you believe the BMS is tracking the soc conservatively 10% in one direct cycle each and every cycle always? That's almost just as poor as actually locking out 10% capacity intentionally and telling us they haven't. It's almost the same thing. I'd understand if it got 10% out of wack over a week but not in 3 hours since it's last full charge to 100%.
Then you must have a faulty system, put in a warranty claim.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 12:34 pm
by MaterialBarracuda48
Beno62 wrote: ↑Sat Mar 14, 2026 10:22 am
My battery was at 10% soc and I charged it to 100% in a single day and the fox app quoted 33.5kwh charged for the day. Exactly 80% of 41.93kw, not the 90% that it should be.
I agree with your 33.5kWh charge value.
Sadly this figure is skewed by the very fact that Fox are reserving 10% of the battery capacity when they should not be.
Once you take into consideration this 10% is locked away.
If we now account for your 10% reserve value...
41.93kWh becomes available to use 37.74kWh
Now you said it charged from 10% to 100%, and increase of 90% and used
33.5kWh.
Now do 90% of 37.74kWh available, gives a
33.96kWh which is close enough to your above used.
Your BMS is calculating things fine, no calibration issues I would say.
Bottom line Fox are locking 10% of your battery off, no amount of setting 0% MinSoc or such globally or in a schedule will help. Fox needs a slap on the wrists by some Government body.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 12:35 pm
by evilbunny
MaterialBarracuda48 wrote: ↑Sat Mar 14, 2026 12:34 pm
Once you take into consideration this 10% is locked away.
Not in batteries sold in Australia, some regulatory thing compared to those sold elsewhere.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 12:55 pm
by Beno62
MaterialBarracuda48 wrote: ↑Sat Mar 14, 2026 12:34 pm
Beno62 wrote: ↑Sat Mar 14, 2026 10:22 am
My battery was at 10% soc and I charged it to 100% in a single day and the fox app quoted 33.5kwh charged for the day. Exactly 80% of 41.93kw, not the 90% that it should be.
I agree with your 33.5kWh charge value.
Sadly this figure is skewed by the very fact that Fox are reserving 10% of the battery capacity when they should not be.
Once you take into consideration this 10% is locked away.
If we now account for your 10% reserve value...
41.93kWh becomes available to use 37.74kWh
Now you said it charged from 10% to 100%, and increase of 90% and used
33.5kWh.
Now do 90% of 37.74kWh available, gives a
33.96kWh which is close enough to your above used.
Your BMS is calculating things fine, no calibration issues I would say.
Bottom line Fox are locking 10% of your battery off, no amount of setting 0% MinSoc or such globally or in a schedule will help. Fox needs a slap on the wrists by some Government body.
You are not talking about Australia when you say 10% is locked away. That's not legally the case here, however that is exactly what Fox ESS are doing here, it's just that they are lieing about it. They are advertising EQ4800 L9 models as 41.93 kWh usable to 100% Dod. All lies.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 12:58 pm
by Beno62
evilbunny wrote: ↑Sat Mar 14, 2026 12:04 pm
Beno62 wrote: ↑Sat Mar 14, 2026 12:03 pm
Ok. You are saying you believe the BMS is tracking the soc conservatively 10% in one direct cycle each and every cycle always? That's almost just as poor as actually locking out 10% capacity intentionally and telling us they haven't. It's almost the same thing. I'd understand if it got 10% out of wack over a week but not in 3 hours since it's last full charge to 100%.
Then you must have a faulty system, put in a warranty claim.
It's not just me. The person who started this thread has exactly the same issue as me to the kWh. Coincidence, I think not. I'm guessing every Australian customer is being deceived by Fox. I don't think it's an accident.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 1:00 pm
by evilbunny
Beno62 wrote: ↑Sat Mar 14, 2026 12:58 pm
It's not just me. The person who started this thread has exactly the same issue as me to the kWh. Coincidence, I think not. I'm guessing every Australian customer is being deceived by Fox. I don't think it's an accident.
I have exactly those batteries and according to the app, website and API have hit 100% on a number of occasions when solar production was under estimated and house load over estimated.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 1:07 pm
by MaterialBarracuda48
Beno62 wrote: ↑Sat Mar 14, 2026 12:55 pm
You are not talking about Australia when you say 10% is locked away. That's not legally the case here, however that is exactly what Fox ESS are doing here, it's just that they are lieing about it. They are advertising EQ4800 L9 models as 41.93 kWh usable to 100% Dod. All lies.
Yes in fact I am talking about Australia.
Legality does not matter, they are clearly (by evidence of you know maths) locking this 10% DoD from your system.
I am in agreement with you, not sure why you are fighting me and the evidence in maths.
Try your 10% to 100% on 41.93kWh, what do you get for charge?
37.73kWh, but you actually input 33.5kWh.
It only lines up once you take off the 10% locked away by Fox, which as I keep saying they should not be doing.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 1:18 pm
by Beno62
MaterialBarracuda48 wrote: ↑Sat Mar 14, 2026 1:07 pm
Beno62 wrote: ↑Sat Mar 14, 2026 12:55 pm
You are not talking about Australia when you say 10% is locked away. That's not legally the case here, however that is exactly what Fox ESS are doing here, it's just that they are lieing about it. They are advertising EQ4800 L9 models as 41.93 kWh usable to 100% Dod. All lies.
Yes in fact I am talking about Australia.
Legality does not matter, they are clearly (by evidence of you know maths) locking this 10% DoD from your system.
I am in agreement with you, not sure why you are fighting me and the evidence in maths.
Try your 10% to 100% on 41.93kWh, what do you get for charge?
37.73kWh, but you actually input 33.5kWh.
It only lines up once you take off the 10% locked away by Fox, which as I keep saying they should not be doing.
Sorry, I misunderstood you. Totally sketchy hey! And they are telling the government 100% usable give us rebate for 100%, just defrauding the government by an additional 10%. How do the government just accept manufacturer claims without any independent testing. So so so sketchy. I'm putting in a case with the ACCC.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 1:22 pm
by MaterialBarracuda48
Beno62 wrote: ↑Sat Mar 14, 2026 1:18 pm
Sorry, I misunderstood you. Totally sketchy hey! And they are telling the government 100% usable give us rebate for 100%, just defrauding the government by an additional 10%. How do the government just accept manufacturer claims without any independent testing. So so so sketchy. I'm putting in a case with the ACCC.
Thank you very much for reading and comprehending.
I have no idea why Fox are doing this, it is cheating you out of the full capacity.
Car analogy: "It can do 180mph!", but yeah we erm limited it to 155mph in Australia, despite advertising 180mph to you.
Re: EQ4800-L9 capacity mismatch: 41.9 kWh capacity but measured ~37 kWh
Posted: Sat Mar 14, 2026 1:32 pm
by Beno62
MaterialBarracuda48 wrote: ↑Sat Mar 14, 2026 1:22 pm
Beno62 wrote: ↑Sat Mar 14, 2026 1:18 pm
Sorry, I misunderstood you. Totally sketchy hey! And they are telling the government 100% usable give us rebate for 100%, just defrauding the government by an additional 10%. How do the government just accept manufacturer claims without any independent testing. So so so sketchy. I'm putting in a case with the ACCC.
Thank you very much for reading and comprehending.
I have no idea why Fox are doing this, it is cheating you out of the full capacity.
Car analogy: "It can do 180mph!", but yeah we erm limited it to 155mph in Australia, despite advertising 180mph to you.
Yeah. So in UK they tell customers you can use 37.7kwh of your 41.93. in Australia they tell you you can use 41.93 of 41.93 but really only give you 37.7 usable but then they recommend 10% min soc so Aus end up being left with 33.5kwh. it's going to take a few months but Fox ESS are going to get one of those big boy fines. The government don't like fraud on their own rebate schemes.