Hi all,
Just been looking at my system, nearly a year old, and found that what I was advised was an ECM2900 master and ECS2900 slave is in fact an ECM4100 and ECS2900! I assume the system will actually work as a 7kwh system rather than 5.8kwh but can the figures be amended in the app to reflect the correct battery sizes and if so who can do it?
Battery information wrong
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Dave Foster
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Actually that is a problem - if you can get your installer back, the battery types with different capacities cannot be mixed, for a 2 battery system you should have either ECS2900 * 2, or ECS4100 * 2 - you can't have mixed capacities - I suspect your capacity will be the size of the battery that has been set as Master (and only that battery).t5pilot wrote: ↑Fri Jan 26, 2024 1:57 pm Hi all,
Just been looking at my system, nearly a year old, and found that what I was advised was an ECM2900 master and ECS2900 slave is in fact an ECM4100 and ECS2900! I assume the system will actually work as a 7kwh system rather than 5.8kwh but can the figures be amended in the app to reflect the correct battery sizes and if so who can do it?
Thanks for the quick response. Spoken to installer and he is going to look into it. Only just found out about the Energy Stats app and that pretty much confirms what you say, I never get more than 3.5kw charge on my battery so it clearly isn’t filling the 2.9kwh slave.
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Dave Foster
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The older batteries are quite difficult to find, although they do occasionally pop up - it'd be nice if you get another ECM4100 to go with your original.
Fingers crossed, let us know how you get on.
Fingers crossed, let us know how you get on.
Installer been a bit of a pain trying to say everything looks ok via the app and another customer with similar system isn’t noticing any issues, but similar is not the same.
As I pointed out, hybrid car discharges battery to SOC (set at 12%) overnight, then battery fully charges from grid to 100% between 5 and 7am. It only takes on board about 3500w, which is the nominal voltage of 4030w - 12% (484w). If it was the full 7000w (nominal 6910w) that the system adds up to then it should take on board about 5600-6000w depending on SOC. Also the slave light on both master and slave unit continually flash, even after the master is full, although I can’t decipher the manual to work out what that means!
I can’t see him replacing the slave with a cs4100 as they are very expensive, but if I get what I originally purchased, 2x 2900w then I’ll be happy
As I pointed out, hybrid car discharges battery to SOC (set at 12%) overnight, then battery fully charges from grid to 100% between 5 and 7am. It only takes on board about 3500w, which is the nominal voltage of 4030w - 12% (484w). If it was the full 7000w (nominal 6910w) that the system adds up to then it should take on board about 5600-6000w depending on SOC. Also the slave light on both master and slave unit continually flash, even after the master is full, although I can’t decipher the manual to work out what that means!
I can’t see him replacing the slave with a cs4100 as they are very expensive, but if I get what I originally purchased, 2x 2900w then I’ll be happy
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Dave Foster
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Yes agree your maths looks correct, you can always get in touch with FoxESS support by email and ask them to confirm that different sized batteries won't work together, although TBH your installer should be able to make that call.
Got a call from installer yesterday. He had spoken to the top tech guy at their supplier and confirmed what you said Dave, can’t run together. So he is ordering new master unit to replace in the next week or so. Now the problem has been confirmed, can’t fault the after sales service
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Dave Foster
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Great stuff, hopefully not long and you'll be up to capacityt5pilot wrote: ↑Tue Jan 30, 2024 1:15 pm Got a call from installer yesterday. He had spoken to the top tech guy at their supplier and confirmed what you said Dave, can’t run together. So he is ordering new master unit to replace in the next week or so. Now the problem has been confirmed, can’t fault the after sales service
Latest update
Yesterday the installers came and removed the 4100 master and replaced it with a brand new 2900 master. They also added a 2900 slave. So there are now a master and 2 slaves, all 2900w (Funnily enough when I use the old app and click on view on the battery screen it shows the master serial number in both the master and slave sections.)
Sure enough after a short while the app auto updated to show the system power of 8640W. Brilliant
Except it isn’t!
Overnight the battery was used to charge the car along with some from the grid. The SOC is set to 20% but the Energy Stays app shows it dropped to 16%. Then charged up this morning to 100% but it only showed 3490W was added. So where are the other 3400w?! 8640-20%
Installer is trying to say it’s because the firmware isn’t upgraded and that is true but I can’t see why it won’t charge to the actual full capacity! Dip switch is set to 1 which according to the manual is correct for 2 slaves. I’m at a loss as to what is wrong now!
As an aside, the slave light on the master battery flashes green, slowly, as do the lights on the slaves. Is this correct or should they be static?
Yesterday the installers came and removed the 4100 master and replaced it with a brand new 2900 master. They also added a 2900 slave. So there are now a master and 2 slaves, all 2900w (Funnily enough when I use the old app and click on view on the battery screen it shows the master serial number in both the master and slave sections.)
Sure enough after a short while the app auto updated to show the system power of 8640W. Brilliant
Except it isn’t!
Overnight the battery was used to charge the car along with some from the grid. The SOC is set to 20% but the Energy Stays app shows it dropped to 16%. Then charged up this morning to 100% but it only showed 3490W was added. So where are the other 3400w?! 8640-20%
Installer is trying to say it’s because the firmware isn’t upgraded and that is true but I can’t see why it won’t charge to the actual full capacity! Dip switch is set to 1 which according to the manual is correct for 2 slaves. I’m at a loss as to what is wrong now!
As an aside, the slave light on the master battery flashes green, slowly, as do the lights on the slaves. Is this correct or should they be static?
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Dave Foster
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That sounds a pretty good result, and what they are saying is not entirely wrong, the packs have to balance before you will get near their full capacity and it is critical the firmware be updated to latest on all the packs.
Until the packs are in balance the battery management system will cut discharge power when the lowest pack reaches 10%, and likewise won’t charge after the highest pack is at 100% which is why you aren't seeing the full power in charge or discharge.
The balancing takes place between individual cells in each pack, and also between individual packs during the charge/discharge cycle but it happens relatively slowly so you will likely need to do at least a few full charge cycles (charge to 100%, flatten to 10% and repeat) before the packs will achieve balance and show their full capacity - if you don’t do full charge cycles it can take a few weeks before they will be balanced.
But the firmware update needs to be done first - is that in hand already?,
Until the packs are in balance the battery management system will cut discharge power when the lowest pack reaches 10%, and likewise won’t charge after the highest pack is at 100% which is why you aren't seeing the full power in charge or discharge.
The balancing takes place between individual cells in each pack, and also between individual packs during the charge/discharge cycle but it happens relatively slowly so you will likely need to do at least a few full charge cycles (charge to 100%, flatten to 10% and repeat) before the packs will achieve balance and show their full capacity - if you don’t do full charge cycles it can take a few weeks before they will be balanced.
But the firmware update needs to be done first - is that in hand already?,
Thanks for the positive reply. Hopefully I’m heading in the right direction then
The installer said he was going to talk to Foxess to find the latest firmware information and upgrade if required so hopefully that will happen in the near future.
I will post later once things settle down and hopefully balancing sorts out everything out
The installer said he was going to talk to Foxess to find the latest firmware information and upgrade if required so hopefully that will happen in the near future.
I will post later once things settle down and hopefully balancing sorts out everything out
Another update.
I’m quite confused now. Got 3x 2.9kwh foxcubes. Voltage suggests all are working properly, currently 180.2v and charging.
Actual usable power 8640wh.
On Saturday just gone, overnight SOC dropped to 53%. (This is unusual as we normally charge hybrid car overnight which takes it down to 20% but no on this day). Following morning, after a charging session from 4am to 7am it was back up to 100% SOC and have taken onboard 4000wh (47% of 8640wh is 4060wh so that was as close as I could expect)
However, on any normal day as I said, we charge the hybrid car overnight which runs the battery down to 20% SOC. after that there still seems to be a bit of leakage as the batteries drop to 19% SOC. But, and this is my problem, during the charging cycle, 4am-7am, the battery only charges up by between 5500wh and 5800wh, although when first installed a couple of weeks ago it did take on board 6300wh for a couple of days.
I’m not sure how these batteries discharge, is it the order in which they are stacked or should they loose charge equally? I can’t see how the drop on Saturday is accurate but every other day it isn’t unless the original slave battery that was linked with a 4.1kwh master has been damaged due to the incorrect connection? If they drain in the order they are stacked then it would make sense that in Saturday the last battery wasn’t used therefore the readings were correct.
I can see the only real way to test this is to take the original slave that is at the bottom of the three and move it into the middle and see what happens then.
Unless anyone has any other suggestions?
I’m quite confused now. Got 3x 2.9kwh foxcubes. Voltage suggests all are working properly, currently 180.2v and charging.
Actual usable power 8640wh.
On Saturday just gone, overnight SOC dropped to 53%. (This is unusual as we normally charge hybrid car overnight which takes it down to 20% but no on this day). Following morning, after a charging session from 4am to 7am it was back up to 100% SOC and have taken onboard 4000wh (47% of 8640wh is 4060wh so that was as close as I could expect)
However, on any normal day as I said, we charge the hybrid car overnight which runs the battery down to 20% SOC. after that there still seems to be a bit of leakage as the batteries drop to 19% SOC. But, and this is my problem, during the charging cycle, 4am-7am, the battery only charges up by between 5500wh and 5800wh, although when first installed a couple of weeks ago it did take on board 6300wh for a couple of days.
I’m not sure how these batteries discharge, is it the order in which they are stacked or should they loose charge equally? I can’t see how the drop on Saturday is accurate but every other day it isn’t unless the original slave battery that was linked with a 4.1kwh master has been damaged due to the incorrect connection? If they drain in the order they are stacked then it would make sense that in Saturday the last battery wasn’t used therefore the readings were correct.
I can see the only real way to test this is to take the original slave that is at the bottom of the three and move it into the middle and see what happens then.
Unless anyone has any other suggestions?
Just to add to the above, with the SOC set to 20% that gives me usable power of 6912wh, hence me questioning why it would only take on board between 5500 and 5800wh when charging from 20% to 100%. I check the battery reading at 7am each morning so it has just finished the charging schedule.
I have a motorhome and from discussions on those forums regarding lifepo4 leisure batteries the BMS’ miss a lot of the tiny discharges so never give a true reading, a shunt been the recommendation in those cases, but even if the same is happening here tiny discharges don’t add up to over 1kwh within an hours use
I have a motorhome and from discussions on those forums regarding lifepo4 leisure batteries the BMS’ miss a lot of the tiny discharges so never give a true reading, a shunt been the recommendation in those cases, but even if the same is happening here tiny discharges don’t add up to over 1kwh within an hours use
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Dave Foster
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They are connected in series, so they charge together and the pack balance is controlled by the BMS - this is often what you see when the pack isn't balanced properly which happens with new packs that haven't finished training (this can take several weeks), and/or more likely when the firmware needs to be updated - did you manage to get the firmware updated on them ?
If you go to the inverter itself and on the panel click About, and select Bat Ver it will show M:xxxxxxx for master version (BMS), and S:xxxxxxxx for slave versions (the packs) - if you can post them here, i'll check to see if they are latest.
As they are new the BMS needs to learn the packs limits, so I would suggest dropping the minsoc's to 10% and let the BMS handle the balancing of the pack - the drop below minSoC isn't unusual, the cell voltage 'sags' during discharge and also when the pack isn't balanced as you tend to get re-adjustments in the SoC as the BMS discovers the lower range of cell voltages - if it drops too low the BMS will start a short maintenance charge (around 1kw) which will also help to balance them.
If you go to the inverter itself and on the panel click About, and select Bat Ver it will show M:xxxxxxx for master version (BMS), and S:xxxxxxxx for slave versions (the packs) - if you can post them here, i'll check to see if they are latest.
As they are new the BMS needs to learn the packs limits, so I would suggest dropping the minsoc's to 10% and let the BMS handle the balancing of the pack - the drop below minSoC isn't unusual, the cell voltage 'sags' during discharge and also when the pack isn't balanced as you tend to get re-adjustments in the SoC as the BMS discovers the lower range of cell voltages - if it drops too low the BMS will start a short maintenance charge (around 1kw) which will also help to balance them.
Thanks again for the reply Dave. The firmware was updated on the batteries, the master is 1.013 and the slaves are 1.10.
Quick question, why does it show 1 master and 3 slaves when there are only 2?
Does it matter that the inverter firmware isn’t updated? They are Master 1.54, Slave 1.02 and Manager 1.57. I’m sure I’ve read on the firmware forum that the Master and Manager are at higher versions now, same with the WiFi dongle, mine is 3.08 and I think it is up to 3.2, though I’m sure that won’t affect any battery readings
I have changed SOC to 10%
Quick question, why does it show 1 master and 3 slaves when there are only 2?
Does it matter that the inverter firmware isn’t updated? They are Master 1.54, Slave 1.02 and Manager 1.57. I’m sure I’ve read on the firmware forum that the Master and Manager are at higher versions now, same with the WiFi dongle, mine is 3.08 and I think it is up to 3.2, though I’m sure that won’t affect any battery readings
I have changed SOC to 10%
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Dave Foster
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Great, those are the latest versions.
Master in this sense is actually the battery management system (BMS) which is the brains that runs the pack, but it also contains a slave - as you have 3 cubes you have 3 slaves and one of them contains the 'master'
Your inverter firmware won't affect batteries at all, generally speaking if it isn't broke don't fix it - but the latest version does have force discharge which allows you to discharge your batteries to the grid.
One last thing to mention, I haven't mentioned temperature and I can't remember if you said where your batteries are - if they are in a roof or garage, it's likely they will be getting cold which also has an affect on their capacity and ability to charge fully, with the recent cold spell that could also be a factor.
Hopefully a few weeks of normal charging/discharging (and hopefully warmer weather) should see them settle down.
Master in this sense is actually the battery management system (BMS) which is the brains that runs the pack, but it also contains a slave - as you have 3 cubes you have 3 slaves and one of them contains the 'master'
Your inverter firmware won't affect batteries at all, generally speaking if it isn't broke don't fix it - but the latest version does have force discharge which allows you to discharge your batteries to the grid.
One last thing to mention, I haven't mentioned temperature and I can't remember if you said where your batteries are - if they are in a roof or garage, it's likely they will be getting cold which also has an affect on their capacity and ability to charge fully, with the recent cold spell that could also be a factor.
Hopefully a few weeks of normal charging/discharging (and hopefully warmer weather) should see them settle down.
The batteries are in the garage, lowest recorded temperature by the BMS in the last 2 weeks was 16.6 deg C on one day. Every other day has had a low of 20, or more, maximum high was 29 when charging.
I’ll leave it until the end of March now and see what happens
Thanks for all you help and advice Dave
I’ll leave it until the end of March now and see what happens
Thanks for all you help and advice Dave