question

Hi Mark,

From the VRM data it looks like the solar production has remained consistent, the batteries are still absorbing charge. The big difference I can see is that your consumption/loads has increased from ~23-24 kWh / day to 29-30 kWh / day.

Nothing appears to be wrong with the system, just an increase in load beyond the system's capacity to supply over several days.

Do an energy audit of the house, check if there are any other users of power and see if they have added any new appliances recently. Begin to disconnect non-essential appliances and see if you can isolate the load that is consuming so much power. Specifically heaters or coolers for an additional load of 7 kWh/ day. Maybe a fridge door as been left open somewhere?

From that data, the firmware update would seem to just be a co-incidence.

There is no surplus PV, it is all being consumed. PV output is maximum and optimal. The loads have increased to the point where they cannot be supplied by the PV anymore and are now coming from the batteries.

The yellow graph here shows a slight INCREASE is solar production, previously the solar panels would reduce output once the batteries were full. Now they cannot produce enough to satisfy the loads and fill the batteries, so production goes UP slightly, but still not enough.

You have doubled the demand coming from the batteries, previously it was 14kWh solar, 6 kWh batteries. On July 2nd that increased to 14 kWh solar and 15 kWh batteries.

ok, i can see this on the 2nd and 6th july

but 1st, 3rd, 5th - all showed positive supply overconsumption, yet it still fell

and the 4th was pretty marginal, but again it dropped significantly....

if you look back prior to 1st july, you'll see the only reason we stop charging at around midday usually, is not lack of sun, but because the MPPT moves to abs/float - which its not done since July 1

also the confusing part of all of this is... nothing has really changed, we have not installed anything new to consume more power - and this system has been running for years like this without issue, Ive never see it plummet like this, particularly in the summer months where we have plenty of sun.

but I will definitely go and look to see if we have something that is constantly pull power....
we are completely off-grid, so we go have a lot of pumps for things like the heating/water and pool systems- perhaps something else has gone awry.

thanks @Guy Stewart (Victron Energy Staff) and @Daniël Boekel (Victron Energy Staff),

I really appreciate your support, esp. given its Sunday - much appreciated as its was kind of all a mystery a couple of hours ago!

(the system has been so stable, so this kind of came out the blue!)

indeed, I think Ive found the sensor that has failed, and was causing the issue of running a pump continuously unfortunately at a place on the site, when it cannot be seen easily! :(

ok, I guess my only problem is now...

Why did I not get alarms much earlier? I only got alarms at 2am this morning, when it had hit 0%

yet, I have a BMV702, which was supposed to be firing alarms off at 60% (which would have been 3 days ago)

we can see its connected ok...

yet i see an odd 'warning' on the alarms

also the remote console on the VRM, shows the voltages etc from the BMV, so it looks all ok, in that its seeing it.

also... Im kind of surprised even if VRM didn't send me alarms,
and I didn't get any beeps, or alarms from the BMV or CCGX, I go into where its all installed a few times a day so would have noticed any alarms there)

if I had been warned 3 , or 4 days ago, when batteries were at 50-60%, I would have done something :)

alarm log:

so you can see prior to these alarms, last alarm was 8 may....

and we can also see it was the battery monitor that did report an alarm at 2am today

... but battery monitor did not report low voltage, but the VE.BUS system did, but only at 0%

again, its a bit unclear, why this was so late ?!