Mode Scheduler Advice and EV charging

[Gazeruth]

Hi all,

Apologies, this has probably been answered before, I have attempted to scour the forum before posting but can't find exactly what I'm looking for. I've also read this guide but still have some questions/issues.

I use Octopus Intelligent Go (but my EV is controlled rather than the charger), so I usually end up switching the times that my inverter can draw from the grid, to match the charging times from Octopus (I haven't automated it all yet), as the draw from the grid is higher than my batteries will produce.

I've previously used the basic "Charging time" on the app to match Off-Peak times, and set one of the times to also charge the batteries as required. This has worked pretty well, and I'm trying to replicate it into Mode Scheduler so that I can add some force discharge sessions when Octopus have savings windows from time-to-time.

The problem is, I haven't been able to properly replicate it (I don't think), as last night when charging my EV, the power draw from the grid was <3kW (see image)

I've set the schedule up as per this image

but I'm not sure if what I've set up is the same as the "Charging time"/"Grid Charge Setting", or if it's not possible to replicate, and I should just stick with the old way of doing it.

Any advice would be welcome, and apologies if this has been asked before!

[Dave Foster]

The old charge periods are probably the easiest to use, but scheduler should work just fine but is a bit trickier - I think you’ll are nearly there with it - your first entry should be set to finish at 05:29 which will end at 05:29:59 (it’s over lapping with the next self use setting at the moment), and likewise the self use entry should end at 23:29 (:59).

The only other thing I can see is that your schedule has not been enabled (top right of your screen), that needs to say ‘Enabled’ and you should be good to go.

[Gazeruth]

Thanks Dave,

Any idea why the power draw was so low? Usually when charging an EV and batteries together my power draw from the grid gets up to nearly 12kW, then once the batteries are charged stays around 6.8kW while charging the EV.

I was playing around with the Templates to see if they would work better, so currently have a "NormalUsage" template enabled - do you still need to enable the "User defined" schedule if you have a template enabled?

[Dave Foster]

If your EV charger is wired so the KH sees the load from it you’ll have 2 problems - the first i’m sure you already know is it will flatten your batteries if you don’t have a charge period set, the second issue is that out of the box the KH has a grid import current limit of 50A (11.5kW).

So if you’ve got 7.2kW going to your EV, and (say) 1 kW to the house load you’ll only be able to charge your home batteries at 3.3kW before you hit the 50A limit and the KH throttles.

The easiest way to deal with it is for an electrician to re-wire the EV so that it splits off at the meter (by installing a Henley block) before the house and inverter connection, that way you’ll never have the problem again.

The quick way to fix it now, is to change the setting ImportLimitCurrent to (say) 80A so that you’ll be able to utilise the full performance of the KH when charging batteries etc..

A couple of quick notes-
- this is available on the more recent firmware updates so as long as you have latest firmware installed there will be a setting,
- the setting is an installer option and so will have to be changed by someone with installer access (i.e. your installer / Fox)
- Don’t set the limit any higher than the size of your house fuse (usually 80 / 100A) but it can be as low as 60A.