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low_price charging

Open tieskuh opened this issue 2 years ago • 2 comments

Hi,

Great integration! I created something like this myself a few years ago but yours has way more functions and is easier to configure.

I have a question/feature request: If I understand correctly, setting a low price limit will enable the charger as soon as the price drops below that level. I most of the time leave my car connected with a limit of 70% to be able to charge the remaining 30% with low prices. Most of the time I don't need a full charge.

But in my experience, the following example happens sometimes:

  • My car is charged 80% which is the set limit for smart charging. The car remains connected.
  • The electricity price drops under €0,10 which is set as the low price charging limit
  • Now the car charges up to 100% for €0,10/kWh
  • The next hour the price drops to €-0,05/kWh

I would have rather wanted to charge for €-0,05 than for €0,10. This scenario happens most of the time as prices usually drop slowly every hour. Maybe it is possible to add a soft limit for the low price that only charges if there are no cheaper prices ahead in the next (4?) hours to reach 100%.


Another scenario:

  • My car is charged 50% and the limit is set to 100%
  • According to schedule the best time to charge is between 12:00 and 18:00, prices are negative during those hours
  • At 8:00 the price drops under €0,10 which is set as the low price charging limit
  • Would the car start charging at 8:00 because it is under the low price limit or would it charge according to schedule?

I think it would be best to not follow the low price limit if a schedule is active. I cannot find what the behaviour would be from the documentation.

tieskuh avatar Nov 06 '23 19:11 tieskuh

I don't understand your first scenario. If the target SOC is 80% (was that what you meant?), then there shouldn't be any charging to 100%.

For the second scenario, if switch.ev_smart_charging_low_soc_charging is activated and the price is below number.ev_smart_charging_low_price_charging_level, then charging will be done. This is indepent of any scheduled charging.

jonasbkarlsson avatar Nov 08 '23 20:11 jonasbkarlsson

Let me try to clarify. If the switch.ev_smart_charging_low_price_charging is activated. Charging will always start if the current price is below the set price. No matter what. What I mean is, let's say the number.ev_smart_charging_low_price_charging_level is set to 0,10. The prices for the next hours are:

  1. 0,15
  2. 0,09
  3. 0,09
  4. 0,05
  5. -0,10
  6. -0,40

Now the car wil start charging at hour 2 according to the number.ev_smart_charging_low_price_charging_level. But it would be better if it waited until hour 5 or even 6 depending of the SOC (if only <1 hour charging can be done to reach 100% it would be better to wait until hour 6).

I leave my car connected most of the time with a target SOC of around 70% to be able to charge if prices are really low. My charger is able to charge the battery 10% per hour. In the example above it would be best to charge in hour 4, 5 and 6. But if the number.ev_smart_charging_low_price_charging_level is set to 0,10 it will charge in hour 2, 3 and 4.

So two features I would like to suggest:

  • It would be better to first follow the schedule and than look at the low_price_charging_level. The schedule always get's the lowest prices. So disregard the low_price_charging_level when a schedule is active. Or even better: check the hours around the schedule for prices below the number.ev_smart_charging_low_price_charging_level and sort them low to high to reach a SOC of 100% and add them to the schedule (only if the target SOC is <100% of course).

  • When the price is below number.ev_smart_charging_low_price_charging_level, check the next hours aswell. They might be lower. Maybe just sort all hours with a price lower than the limit and charge in the hours from low price to high. Could be a seperate switch.

Feel free to close this issue!

tieskuh avatar Nov 08 '23 20:11 tieskuh