FoxESS Community - Owners & Installers Forum

Hi all.

Newb around here that enjoys content and just dipped toe in to all things solar of the fox ess variety.

currently have H1-5 hybrid inverter, combined with 10*400w south facing panels all connected to Home Assistant via usb modbus.

All fitted myself with electrician friend and all working perfectly

I recently had the opportunity to buy storage in the form of a cm2900 master plus three cs2900 slaves but try as I might I simply cannot get any life out of the master when power on.

Tried normal start up plus depleted startup using the black button but no matter I get no life from the unit at all.

I believe they should come 50% charged but is there any way to test before I ask the supplier to replace.

Supplier says not had any previous issues.

Many thanks.

As a general rule, the master will power up with no slaves connected as long as the dip switches are set correctly - even if they are not you would expect it to flash an error code.

You should be cabled to the inverter as per the manual DC+/- and canbus connected - and at a minimum you need to have 1 master and 1 slave to start up.

At that point close the battery isolator switch, then press the power switch and you should see the Master light followed shortly by the BMS LED, then after a while the operating system leds should light, if the master LED is red there is an error and the soc leds will show the 'code'.

If it doesn't do anything at all, it sounds as if the master is faulty (or the battery flat), either way that's a send it back to your supplier job.

Thanks Dave.

I get no lights to come on at all no matter what I try.

I am awaiting a call from fox but I suspect the master is faulty.

I would expect even powering on with the master not connected to anything that I would see some led indicators flashing if the unit was viable

Fox support were excellent and spotted it straight away.
My stupid fault.
I hadn't put the weatherproof blanking connector in the bottom slave as didn't think it was needed given it is in the loft but it seems it is essential to complete the circuit and the system won't boot without it

Lesson learned