How long should the batteries hold the charge

[huminga1]

Hi,

I have been charging our batteries overnight on the slightly cheaper Octopus Flux tariff. The last 2 nights I have noticed that the batteries have charged up to 100% then discharged to about 40 to 50%. This is happening during the night when there is very little draw from the grid as most energy sucking devices are switched off.

Is this normal ??? Are the batteries faulty ?
We have not had this problem before , there only difference over the last few days is that the outside temperature has been sub zero. The batteries are in our garage.

I have tried to attach an image

Any thoughts regarding this ?

Many thanks
Belinda

[Dave Foster]

That graph is showing quite a substantial load being drawn over night - do you have any heaters running, or an EV charging.

[huminga1]

Hi Dave,

No heaters on at night . I figured the big draw is the batteries charging over night from 0100 to 0600.

[huminga1]

No EV Charger either

[Dave Foster]

Hi Dave,

No heaters on at night . I figured the big draw is the batteries charging over night from 0100 to 0600.

No the batteries charging doesn't show as load (it shows as 'battery' instead), you have something switching on in your house which explains why the battery is draining - given it's cold at the moment do you have any kind of heater, greenhouse, garage, space heater that will now be coming on.

It's easier to see the load if you log into the website foxesscloud.com, and you will see it at the bottom of the first page - click on the label to remove output power and that will just show your grid consumption and load power over 24 hours. - you can scroll backwards through the date on the right and hopefully see where it started.

[huminga1]

Hi Dave,

Thank you so much for responding . I'll have a look at this. I cant think what could be on..... Would the oil central heating kicking in about 6.30 am do it ?

Anyway, Ill have a good look at it and many many thanks for the advice, really appreciated.

Best wishes
Bel

[WyndStryke]

Could it be a CT clamp wired backwards? Can cause all sorts of confusion. See if you can see an arrow moulded onto the clamp, and check whether it points towards your consumer unit or towards the grid.

[huminga1]

Thanks, I will check on this but its all been working perfectly until the recent cold snap.
Many thanks for responding
Belinda

[huminga1]

Another quick question, where do I look to see what the current battery temperature is ? Sorry if this is a stupid question

[Dave Foster]

If you have the V2 app, click on 'Device' at the bottom, click on 'Battery' at the top and you''' see it there to the right of the battery graphic - this shows the lowest battery cell temperature in your stack (which is what the BMS uses to control charge/discharge power).

[huminga1]

Thanks Dave ,
Got it !