Add option to "Run until Complete by"

[jpalo]

When option is selected, Smart mode of Demand Shaper will use the calculated optimal hours as usual, but will leave device ON until the "Complete by" time.

Reasoning is that at least with OpenEVSE you will want to optimize battery charging to occur during cheap hours, but still want to use electricity (and not car battery) when heating/cooling the cabin/battery, which starts like 10-30 minutes before leaving ("Complete by time") - depending on outside temperature.

[glynhudson]

Fantastic! This is a great idea, we've been considering the best way to handle pre-heating requirement.

However, what if a user does not want to charge to 100%? Leaving the OpenEVSE "on" after the scheduled charging finishing time will result in the EV always carrying on charging until it's full.

[jpalo]

I believe that is pretty much impossible to do that perfectly from DS perspective without commanding car via OVMS to stop charging battery but allow using power for pre-heating.

Sub-optimal way to tackle that would be to define how many minutes before the 'Complete by' should the charging would start again. For 100% charging users that would not make any difference compared to this PR, but for below100% charging users it would be somewhat better.

It might make sense to only show this when Control based on Charge time is selected, at least for now?

What are the reasons for below100% charging users? Are they minority or majority?

[dbrooke]

What are the reasons for below100% charging users? Are they minority or majority?

I normally only charge to 80% as it is usually sufficient and should help with battery life. My 24kWh LEAF has a setting specifically for this purpose but I prefer to not use that as I have to disable it in the car on those occasions when I need a full charge.

As for pre-heating I use a home automation script to first enable OpenEVSE and then signal the car to pre-heat. I've not yet had demandshaper interfere with this but that may be because I have pre-heated after the end of the demandshaper schedule.

[jpalo]

I've been thinking this and come to conclusion that while this switch isn't a silver bullet for all pre-heating use-cases, it is at least helping to solve it in some cases.

If that switch doesn't support how an individual is charging their car, they just leave the switch off.

[jpalo]

Updated changes from master.