Fox Ecs batteries not charging to the max

[TH3ME4T]

Hi. I've recently had another fox Ecs4100 battery added to my stack and it's not charging to the full capacity. I did notice when the installer added them they original batteries were at 75% soc. The daily charge energy is only saying 8.7kwh which varies a little but it should be way closer to the 12090 which 3 batteries take. I have taken the batteries down to 10% and then all the way up at night to try and cycle the batteries but it's been 14 days now with no luck.

[Dave Foster]

Fox specify that when new batteries are introduced to the pack that the pack should be at 50% SoC as the new pack will be very similar.

If your pack was at 75% then it will be well out of balance and you will loose 25% of 2 batteries until the balance recovers and that will take some time (many weeks) but there are things you can do to help, charge cycling from 100% to 10% and back to 100% is the only way to speed up this process. Getting to 100% and back to 10% is an important part of this as that is where they do most balancing.

The batteries do a ‘top balance’ when they pass the pack SoC of 95% - the slower they charge these last few % the easier it is to balance - so rather than force charging, if you raise the minSoC on grid to 100% (called Battery Reserve in the V2 app) it will slowly charge from grid and allow a longer balance period (make sure you change it back to 10% afterwards).

Likewise allowing the battery to go to 10% and leaving it there for several hours will also help with the balance.

It’s quite a significant difference to start with and it takes time to recover, but if you do as many charge cycles as possible using the slower charge method it will get there faster.

[TH3ME4T]

Hi Dave. Thanks for your reply! Would it speed up the process if I took the new battery off at 75% soc and then drain the original 2 batteries to 50% and then place the new one back on? Thanks Oliver

[Dave Foster]

Hi Dave. Thanks for your reply! Would it speed up the process if I took the new battery off at 75% soc and then drain the original 2 batteries to 50% and then place the new one back on? Thanks Oliver

Hi, yes it would do - but the new battery will no longer be at 50% as it will have closed the gap, possibly more likely 60%.
The only sure way to tell would be to measure the dc voltage with an accurate meter and when each battery pack is at a similar pack voltage they will be close.

Rather than do that you could also try a couple of slow charges on the batteries - get the batteries near 85% then turn the charge off and raise the minsoc on grid to 100% (aka battery reserve on V2 app), that will slowly raise the batteries charge at 4A dc and will allow a much longer, deeper balancing before it gets to 100%.

[TH3ME4T]

Perfect will give that try for the next couple of weeks

[TH3ME4T]

I've tried to set my min soc on the new app to 100% and when I do that it just imports from the grid to meet the house load. It doesn't seem to trickle charge the battery the battery just stay at the same percentage they were on (85%)

[Dave Foster]

I've tried to set my min soc on the new app to 100% and when I do that it just imports from the grid to meet the house load. It doesn't seem to trickle charge the battery the battery just stay at the same percentage they were on (85%)

Ok they will do as your original 2 batteries will likely be at maximum cell voltage (aka 100%) the other battery is holding the pack - if there is no charge going into the batteries then flatten them again but on the next cycle set the minsoc value when the pack is at a lower soc - try 75% and that will give them more time to balance.

I didn't ask before but I think worth checking that your installer has updated the firmware on all of the battery packs, the easiest way to tell is by going to the foxcloud website, into the Inverter Details page and click on the right hand side where it shows the battery on the words 'Battery Status'.

if you can post your versions i'll check them against the latest release - but if any of the slaves is different they all need to be updated to the same version, if you email Fox service with your inverter serial number and ask them to update them battery firmware they usually sort that in a couple of days.

[WyndStryke]

Not the OP, but since we are talking battery versions ...

Got this from the 'battery status' link on the upper-right of the inverter screen (so a different position).

Battery information
Battery Master
60KMxxxxxxxxxx ECS4300 1.004
Battery Slave
60KMxxxxxxxxxx ECS4300 1.01
60KSxxxxxxxxxx ECS4300 1.01
60KSxxxxxxxxxx ECS4300 1.01
60KSxxxxxxxxxx ECS4300 1.01

Would it be safe to say that these are the older versions of the firmware? System installed today. I want to use the mode scheduler to force charge/discharge, and apparently that needs a relatively recent firmware.


Just trying to find my way around. System started off charging at 1.2kW until it reached 5c on the battery screen (batteries are now indoors, but presumably they got cold while being stored outside while the installation was happening), and now it is balancing the house load.

[Dave Foster]

Not the OP, but since we are talking battery versions ...

Got this from the 'battery status' link on the upper-right of the inverter screen (so a different position).

Battery information
Battery Master
60KMxxxxxxxxxx ECS4300 1.004
Battery Slave
60KMxxxxxxxxxx ECS4300 1.01
60KSxxxxxxxxxx ECS4300 1.01
60KSxxxxxxxxxx ECS4300 1.01
60KSxxxxxxxxxx ECS4300 1.01

Would it be safe to say that these are the older versions of the firmware? System installed today. I want to use the mode scheduler to force charge/discharge, and apparently that needs a relatively recent firmware.


Just trying to find my way around. System started off charging at 1.2kW until it reached 5c on the battery screen (batteries are now indoors, but presumably they got cold while being stored outside while the installation was happening), and now it is balancing the house load.

Thanks, got my left and right mixed up - edited now.

Yes they are older versions of the battery firmware, updating won’t do any harm and they will likely be much more stable.

But the battery firmware won’t restrict the schedule function, if your scheduler is greyed out that means the inverter firmware needs updating - if you check your inverter firmware (in the V2 app click the Device page, Inverter and click on the inverter serial number you are looking for Master and ARM (Manager) versions.

Low temperature is the biggest constraint you will see anything below 20C and they will start slowly throttling discharge and charge (but mostly charge), below 10C and your charging power will be severely restricted, at 0C it’s all over.

Once they have started charging the battery temp will pickup fairly quickly.

[WyndStryke]

...

Yes they are older versions of the battery firmware, updating won’t do any harm and they will likely be much more stable.

But the battery firmware won’t restrict the schedule function, if your scheduler is greyed out that means the inverter firmware needs updating - if you check your inverter firmware (in the V2 app click the Device page, Inverter and click on the inverter serial number you are looking for Master and ARM (Manager) versions.

...

Many thanks for that!

I see Master 1.34, Slave 1.01, ARM 1.28. This is for the KH7.

That seems much more recent than the battery firmware... I think 1.34 is from May or so, based on the firmware subforum. Is there any reason to update that, or is it good enough?

Low temperature is the biggest constraint you will see anything below 20C and they will start slowly throttling discharge and charge (but mostly charge), below 10C and your charging power will be severely restricted, at 0C it’s all over.

Once they have started charging the battery temp will pickup fairly quickly.

The door was open all day while they were installing, and the battery modules were outside, so it got pretty chilly. Given that it was -2 outside, normally I'd expect that room to be around 10-12c if the door hadn't been open. The inverter is in there too, so I'm sort of expecting the room to take some warmth from that too, in the future.

[Dave Foster]

Many thanks for that!

I see Master 1.34, Slave 1.01, ARM 1.28. This is for the KH7.

That seems much more recent than the battery firmware... I think 1.34 is from May or so, based on the firmware subforum. Is there any reason to update that, or is it good enough?

Ok yes quite recent, the latest are Master 1.39, Manager (ARM) 1.35 and as it’s quite a new inverter it has had more updates than you would normally expect in a short space - unless you have any issues or the opportunity arises with your installer it is probably best to wait a few weeks and get the inverter and batteries done together.

[TH3ME4T]

Master is 1.16 and the 2 slaves are 1.14. they were updated probably 3 weeks ago so I'm guessing they are going to be somewhat near the latest firmware. I'll give it ago again tomorrow just dropping the soc down to 75%.

Just on the curious side, would this have damaged the batteries do you think if they put them on at 75% soc or just a matter of waiting for them to balance which could take a month

[Dave Foster]

Master is 1.16 and the 2 slaves are 1.14. they were updated probably 3 weeks ago so I'm guessing they are going to be somewhat near the latest firmware. I'll give it ago again tomorrow just dropping the soc down to 75%.

Just on the curious side, would this have damaged the batteries do you think if they put them on at 75% soc or just a matter of waiting for them to balance which could take a month

Ok the firmware is fine, just thought i’d check

No the batteries won’t be damaged at all, each pack maintains their individual cell balance and the BMS attempts to regulate the pack. The balancing circuits can’t handle large differences which is why Fox ask them to be at or near 50% when a new battery is added, by slow charging them you give the balancer circuits more time for the pack with the lowest cell voltage to catch up with the others but it all takes time.

[TH3ME4T]

I'll just have to persevere with them. Just annoying as I could do with that extra but of battery storage now but hey ho. Thanks very much for all the information, I'll just give the stack time now