lincomatic / open_evse

Firmware for Open EVSE
GNU General Public License v3.0
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Energy Limit: additive rather than cumulative #96

Closed glynhudson closed 5 years ago

glynhudson commented 5 years ago

Currently, the energy limit is added onto the current elapsed energy e.g. if an EV has charged to 5kWh and then user applies an Energy Limit of 6kWh the charge will not stop until the elapsed energy has reached 11kWh.

I think a more consistent user experience would be for the charge to stop when the elapsed energy reaches the energy limit e.g. 6kWh in the above example. What are your thoughts on this?

I've tried to illustrate with a video, sorry it's a bit of a ramble: https://photos.app.goo.gl/CYVaFccno2mLa4ih9

lincomatic commented 5 years ago

Sorry, I didn't see this until just now. Actually, the charge & time limits were designed to extend the current session, rather than be absolute limits, as is documented in rapi_proc.h:

SH kWh - set cHarge limit to kWh NOTES:

The thinking at the time was my typical usage.. I would walk up to the car after it'd been plugged in a while, see how charged the car was from its own internal gauge, and then decide how many more kWh I needed in order to make my trip.

But I can understand how a typical user could think of it as a hard limit rather than an extension. Therefore, I've changed both charge & time limit to your liking in v5.1.0

glynhudson commented 5 years ago

Sorry for the slow reply. Thanks a lot for the change, a number of users had also mentioned this to us. I think the limits are more intuitive now. I've just tested the changes and the limits now work great. Thanks again 👍