BatPlan looking to charge for the majority of the day

[TheSargey]

Describe the bug PredBat is looking to constantly charge the battery throughout the day and only set to idle at 4pm when the expensive rates of import on Agile kick in.

Expected behavior Normally PredBat will balance import with idle to use the battery through the day but ultimately ensure that a full charge has occured by 4pm. It's unusual to see PredBat charging constantly through the day. I haven't adjusted settings so I'm unsure how to decipher why it has decided to do this.

I'm wondering what specific variables should I be looking to amend to get a better plan - I've been through the guides on customisation and configuration and seem to be matching what is proposed as best for my setup (Agile import no export).

Predbat version

v7.16.8 (tried switching back to 7.16.5 to see if it made any difference)

Environment details

• GE 3.6 Gen 1 inverter -- 2 x 5kW batteries
• Standard HAOS installer

Screenshots

Thanks as always for your help, really appreciated.

Sarge

[gcoan]

Looking at your plan, a few things stand out:

• you don't have a lot of solar generation compared to your house load, so you are not going to get a lot of solar generation
• the agile rates tomorrow are pretty constant so there is not a lot of benefit of predbat charging up and then letting the battery discharge

Depending on what you have your battery and inverter losses set to, you will lose 10-20% overall on charging and discharging the battery, so in effect you need that kind of difference in the import rates during a time period to make it worthwhile predbat to let your battery discharge.

My own plan for tomorrow is a very similar shape:

I think its just a function of the agile rates brought about by the relatively constant agile rates. On a day with more rate variation you'll see a different pattern of battery use

[TheSargey]

Hi @gcoan, thanks as always for your speedy responses.

I see, makes sense I suppose - I've not really fiddled with the input_number.predbat_inverter_loss, input_number.predbat_battery_loss and input_number.predbat_battery_loss_discharge percentages so I'd assume if I did so this would force PredBat to calculate differently in this scenario.

I think I'm just having a hangover from using Octopus R&D to set charge, which were relatively static timewise but would pick the best slots during a given period to charge.

Basically, I just need to stop micromanaging and let BatPred do it's thing!

Again, thanks for your response, really helpful as always.

Best,

Sarge

[gcoan]

no problem. I saw the issue and thought I could help

People on the givenergy forum have tested conversion losses and seem to end up with answers in the range of 10-20% so as a rule of thumb, input_number.predbat_inverter_loss, input_number.predbat_battery_loss and input_number.predbat_battery_loss_discharge percentages should be set to something in that range, and 15% overall is a reasonable midpoint.

Mine are 4%, 5.5% and 5% respectively for example. There was a reason why I put charging up to 5.5%, can't remember what it was but there was some (not much) science behind it.

yes it is easy to want to micromanage predbat. For diminishing pence of benefits usually !