Bruce, others, This has come up before - free versus paid charging - free without time limit invites people to mooch off (J1772) outlets, such as RV owners squatting on EVSE (even getting free RF-ID cards) and running their RV from the free 240V plug with a NEMA 14-50 converter. It has been said that it is better to program the EVSE to allow a free charge for a limited time, probably depending where they are installed, for example a typical employee charging station would allow free charging for a morning or an afternoon after which the charging is stopped or an hourly fee starts, which encourages EV owners to free up the spot for other EVs. At a typical mall / rest stop / parking garage it makes sense to allow for example 2 hours of free charging to give EV owners the opportunity to shop / dine / rest and be on their way with up to 12 kWh extra charge (level 2 typically is installed on a 30A circuit, allowing 24A continuous at 240V = 6kW for 2 hours = 12kWh) This means that a Leaf battery can be topped up 50% to allow a return trip or additional errands. This allows a visit that uses 70% of the charge one-way and still make it home again: leaving home at 100%, arriving at the charger 30% topping up to 80% and driving home down to 10%, then recharging at home.
Of course, this is a compromise and as always, there are plenty cases for which this is not ideal, but there are also drawbacks to unlimited free charging, including locals squatting on the EVSE to avoid the electric bill from charging at home. I must confess that I am all too happy that my employer allows me to charge at work, so occasionally if I still have over 70%, I won't charge at home since I can comfortably make it to work the next morning and charge there, also avoiding short-cycling my pack, which may lead to extra wear and tear from too many charge-to-100% events - I rather charge as few times as possible while at the same time keeping my pack charged as much as I can, since Lead-acid does not like to sit discharged... I have a charger that does not have the option to stop at 80%, it always attempts to charge to full (timeout after keeping the voltage 2 hours above the 2.45V per cell level) and I can throw a switch to "equalize" which keeps the voltage above 2.45V per cell for 6 hours. I plan to make an additional charger that will allow me to draw more power from 240V (currently the power is limited to ~2kW) as well as allowing me to reduce the charge limits and time, so I can charge more conservatively if I like. I have also bought a "pool timer" mechanism that will allow me to charge for a chosen period of time or utilize ToU rates if/when they are rolled out here. Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: [email protected] Private: http://www.cvandewater.com Skype: cor_van_de_water XoIP: +31877841130 Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203 -----Original Message----- From: [email protected] on behalf of Peri Hartman Sent: Sat 4/12/2014 9:41 AM To: 'Electric Vehicle Discussion List' Subject: Re: [EVDL] Another SF installation: Volta free charging. They have a good idea - using advertising to keep the user cost free (or low, perhaps in time). I wonder if they can make arrangements to install these at freeway rest areas. Lots of viewers for their ads and a good place for an EV driver to stop, rest, and charge. Peri -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Bruce EVangel Parmenter Sent: 12 April, 2014 9:34 AM To: Electric Vehicle Discussion List Subject: [EVDL] Another SF installation: Volta free charging. For those that don't know, Volta is an EVSE company that offers free charging that is paid for by their advertisers/sponsors. Originally starting/beginning in Hawaii, they are slowly installing their free L2 EVSE in the U.S. mainland. Their web site (URL below in original post) only shows their 22 4th Street, San Francisco, CA EVSE. And this new Volta EVSE would be near 265 Winston Dr San Francisco, CA 94132 which is ~7mi away from the first. So, it is likely this is a second Volta EVSE in SF, see http://goo.gl/maps/HoKcV and likely in TJ's parking lot, see http://goo.gl/maps/2oYq8 I have written to Volta about their slow loading web page before, but just sent another message to them asking them to rework that main page so it loads faster without all the clutter of too many full size images. It takes a lot to have a business run smoothly. Weaknesses in certain parts can be their down fall. In this case, it is like the owner or their management is still living with the mindset of pre-1990's Internet thinking their web site is of little importance. Whereas, the rest of the world knows, your company's web presence is vital to what the public, nay investors will think of them (not unlike the way your business card looks). All I can do is advise, but sadly, I am blown off as a hobbyist (where they rely on their 'professionals' to advice them, who actually could care less about them). It reminds me of the days of ol' when the king's court was full of self-serving advisers, and all the peasants who do the work had no voice ... (but I will persist in my EV efforts). {brucedp.150m.com} - On Fri, Apr 11, 2014, at 10:52 PM, [email protected] wrote: > I just saw this new installation in Stonestown in San Francisco. Across > from Trader Joe's. > http://www.voltacharging.com > Lawrence Rhodes - -- http://www.fastmail.fm - Same, same, but different... _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
