FoxESS Community - Owners & Installers Forum

I have just added a 4.14kwh slave to our energy cube set up and it doesn't seem to be charging.

The new capacity is showing in the Energy stats app, but it drops from 50% to 20% very quickly as though the new battery's capacity is being skipped.

I'm sure this is a newbie question so if it is, apologies.

Thanks in advance

When you add the battery the pack must be at 50% as that is the approximate charge new batteries are shipped with - if the charge level was different it will take the pack some time to balance, and you will need to do a number of full charge discharge cycles (to 100%, back to 10%, back to 100%) cycles to help restore balance.

It's also likely that the new battery is running a different firmware to the rest of your pack which is not good for the long term balance of your pack, you can see the firmware versions at the inverter panel, by selecting About, Bat Ver and all the slave versions should be the same - if they are not email Fox service with your serial number and ask them to update your battery versions.

Thanks Dave. That makes sense. I found this forum only after I discovered a problem so at installation the pack was at about 75%.

Incidentally it looks like the versions for batteries are all the same, but it's hard to tell as each version number has a prefix. Like this

S1: 01.00.1.01
S2: 02.00.1.01
S3: 03.00.1.01
S4: 04.00.1.01

Do you know if is that the same firmware for each?

Yes that's the same firmware for each - it is however quite old, I would recommend getting them remotely upgraded by Fox as the latest versions have a number of fixes for stability and low temperature handling.

If the pack was at 75% that will be the primary reason it is doing what it's doing - if you can make sure when you discharge the pack to 10% you leave it there for a couple of hours before recharging, it will allow for some balancing to take place at the bottom, and likewise when you do a full charge keep the charge period running for an hour after they have reached 100% - all of that will help balance the pack but it might take a week or two before the jump in SoC disappears altogether and you get the full capacity of the batteries.

Bangin. Thanks Dave you are a wonderful human being. I'll get on to Fox to remote update the firmwares.