[Ovmsdev] CHARGEBY / CHARGEAT timing

Mark Webb-Johnson mark at webb-johnson.net
Fri Oct 18 09:00:50 HKT 2013

I'm seeking people's opinions for the ACC CHARGEBY / CHARGEAT timing behaviour.

The problem I have is to decide what algorithm to use for the case that people plugin after the scheduled charge time (or in the case of CHARGEBY, plugging in with a charge predicted to take to long to complete by the scheduled charge time).

For example, say I have CHARGEAT set to 19:00:00. I get home, and plugin, at 19:10:00. What should we do? Schedule the charge for 19:00:00 the next day, or charge immediately? The logical choice seems to be charge immediately, but how far do we allow that 'nice' behavior to go? 19:10:00? 20:00:00? 23:00:00? etc?

I guess we need some threshold, but what do people think is a sensible value for that threshold?

For CHARGEBY, it is slightly more complicated. Say I plugin at 18:00:00, with a CHARGEBY of 21:00:00, but the prediction says 4 hours is required? What to do? What if, for the same case, I plugin at 22:00:00?

The current algorithm in ACC does not allow any safety threshold. If CHARGEAT is 19:00:00 and you plugin at 19:01:00, tough luck - the charge will start at 19:00:00 tomorrow. For CHARGEBY, we do check if there is enough time to complete the charge before the scheduled time in the same day - if not, we send a charge alert message and start charging immediately.

What do people think? Remember that this is a small embedded processor without much ram/flash, so we need to keep things simple.

Regards, Mark.

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