for the last few months i have an issue where my WM4 connected to my multiplus inverter goes into a fault state because the celmons “timeout” in order to repair this, i need to pull the power feed to the WM4 and reboot it. Then they all come straight back online.
The WM4 to celmons is via a 1M length of twisted pair ethernet cable as the original leads were not long enough for where it had to be routed. and for 4 years, i never had a fault. now they are almost weekly and some times multiple times per week.
When it happens again next time, i will check the first celmon to see what the LEDs are doing.
Device sync does nothing. i have to either power cycle it by pulling the power on the WM4 or even unplugging anywhere in the link chain on the blockmons restores it to working. for example, i can unplug it on the WM4, or i can break the chain between any 2 random blockmons and reconnect.
I’ve been using longmons (up to 140 on my home powerwall) these last 8 years. In the early period, it all came down to wire and connections - e.g. I switched to Cat6 twisted wire to bridge short distances that the base cables couldn’t reach and most of my ‘freezes’ went away.
Since then, last 7rs, occasional ‘freezes’ - maybe twice a year - occur during severe weather/humidity changes (battery is under the house in non-HVAC area with vents to outdoors). To fix I simply touch/wiggle the connector at the longmon where the freeze occurred (I can tell by the LEDs) and problem is resolved. I’m assuming hi humidity can cause just a touch of network communication failure at a connector after several years?
I’m not familiar with blockmons but assuming they have a connector and if you go thru and just touch/wiggle each connector - the freezes may smooth out for a few years
It would be good if " Ignore overdue cellmon " worked.
The system should just tell you it has a problem not turn power off to your house just because a spider has taken a dump on a connector.
I could see 'Ignore overdue cellmon" for a period - maybe a couple of days - as a battery bank doesn’t (typically) go into a dangerously unbalanced state quickly and discharge or overcharge danger could switch to voltage as a backup via the shunt.
The freezes I experience need attention as they don’t self correct, so the “Ignore overdue cellmon” couldn’t be indefinite. Maybe allow a duration setting? - that would be cool. And allow a switch to shunt voltage for overcharge/discharge protection while the cellmons are ‘offline’?
In general, we’ve found our K9s to be much less flakey as the years go by, so at this stage I think it’s unlikely we add this bandaid to the software, but I am interested in the fact that Ignore Overdue CellMon doesn’t appear to be working for you.
Are you also getting successful messages coming occasionally with low cell voltages as well? Also worth saying is there any chance the cellmons are going under 2V? (this will cause them to stop working altogether).
ok, it has finally happened when i have been home to look at it.
There are no flashing lights on the celmons. and i confirmed again that the only way to repair is to power cycle the WM4 by physically unplugging it and plugging it back in. Even a reboot from the toolkit does not help.
Any suggestions on where to go from here. As this is a critical part of the system, i cant have it keep going down like this. it has happened 3 times so far in 2026.
I dont seem to have the “ignore overdue celmon” option in the toolkit software.
Click Menu , Control Logic , Edit , Extra Parameters
Top right of the box
but it dose not work for me.
I tested it by breaking the cellmon string " unplugged the cell link cable"
It would be nice if the system told you it had a problem before shutting down the power.
K9’s are not an option you cannot bypass sufficient current.
I was thinking of making sum blockmons that can bypass 10A
Large old pifepo4 cells can take a while to balance when restricted to 2A
