garygid
Posts: 187
Joined: Fri Oct 05, 2012 10:19 am
Location: Laguna Hills, CA 92653
Contact: Website

Re: percentage charge...

Tue Dec 25, 2012 8:00 am

The LEAF protects the charging and discharging process
so that no cell (96 cell-pairs) gets too high, or too low,
and that the cells stay within a "usable" range of the
"real SOC", which is 95% SOC when filled to 100% usable.

Filling to 80% usable (80% "real SOC") is the other charging
option given by Nissan, which many use whenever they
do not expect to travel very far the next day.

When charging with Chademo, and starting below 50%,
the LEAF stops the charging at 80%. When starting
(or re-srarting) the charging above 50%, the LEAF
will continue charging (at decreasing currents, controlled
by the LEAF's internal charging controller) until "full".

So, the LEAF certainly tries to protect all the 96 cell pairs.
LEAF owner, EV supporter

jray3
Posts: 1646
Joined: Tue Dec 06, 2011 1:05 am
Location: Tacoma area, WA
Contact: Website

Re: percentage charge...

Mon Jan 07, 2013 11:24 am

marlon wrote:I've been charging with a kill a watt. To my surprise, the charging has been almost completely linear right to the point where is shuts off.

Any thoughts?

Marlon


Marlon, I assume you're charging with only the Panasonic Level 1 unit at about 960 Watts. At that low a charge rate, there's much less reason to taper down.
For those of us using Level II and want an 80% charge option for better battery life, I want a timer option better than the remote delay, which requires a mental calculation every time one plugs in (oh horror :shock: ), plus the risk of an uncharged car when unplanned travel needs arise. In short, I want a relay that will disconnect the charger when the charge rate tapers down after bulk charging is complete. That seems a good compromise for daily use to maximize both battery life and vehicle utility, and is built into EV conversion chargers like the Manzanita Micro PFC series. (One should still do an occasional full recharge for balancing purposes.)

Any ideas on implementing such control? I'm picturing an offboard relay in a box that opens when current detected drops below a certain level, and resets upon J1772 disconnect. It would also need a microswitch to disable this feature, and the pause in charging that has been documented by others could create false stops...
2012 i-SE "MR BEAN" 105,400 miles
2000 Mazda Miata EV, 78 kW, 17 kWh
1983 Grumman Kurbwatt EV,170 kW, 32 kWh
1983 Mazda RX-7 EV 43 kW 10 kWh
1971 "Karmann Eclectric" EV 240 kW 19 kWh
1965 Karmann Ghia Cabriolet

Don
Site Moderator
Posts: 2872
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: percentage charge...

Tue Jan 08, 2013 11:49 am

Jay,

You sound like someone who might be interested in playing around with the Open EVSE project - You can program it yourself do all sorts of things, *if* you're a programmer type. I'm not, so mine uses the standard code that Chris provided - That allows me to set whatever charge current I like (in steps between 6A and 20A) on both L1 and L2. I have no doubt it could be programmed to do what you want . . . . to shut off at some point when the current draw begins to taper off. I've been lobbying them to add some timer features to the code, but the Leaf guys there seem to have lost interest in any more programming for the 'basic' model like I built. Most of the effort these days seems to be making it into a 75 amp EVSE for the Tesla's which come equipped with dual 10Kw chargers

At any rate, it's an enjoyable build - You can make pretty much anything of it you'd like and it doesn't cost a lot compared to similar commercially available units. I have less than $400 in mine

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

garygid
Posts: 187
Joined: Fri Oct 05, 2012 10:19 am
Location: Laguna Hills, CA 92653
Contact: Website

Re: percentage charge...

Sat Jan 12, 2013 8:06 am

The OpenEVSE project, extended by "goldserve" has added a Real
Time Clock (RTC) with backup battery to the project, with the 1.6.2
version of the firmware adding RTC support, and charging Timers
to the firmware. See this thread:

http://www.mynissanleaf.com/viewtopic.p ... e2d7f1a478

The main OpenEVSE thread is long:

http://www.mynissanleaf.com/viewtopic.p ... e2d7f1a478
LEAF owner, EV supporter

jray3
Posts: 1646
Joined: Tue Dec 06, 2011 1:05 am
Location: Tacoma area, WA
Contact: Website

Re: percentage charge...

Mon Jan 14, 2013 11:51 am

Don wrote:Jay,
You sound like someone who might be interested in playing around with the Open EVSE project -
Don

Thanks Don- I even look like a geek too, but have somehow managed to muddle through life without soldering skills thus far... However, you've sparked a thought! I've been using an analog glass dome utility meter mounted on a little box to log my EV charging, and have been itching to rebuild it onto a real 'spider box' that has all the common outlets. Since I already added the J1772 inlet on my Karmann Ghia EV and have the Leviton J1772 30 amp cable (feeding that car in 'dumb' mode at home and with the Manzanita "Smart Box" adaptor in the wild), I've already got the most expensive part of Open EVSE taken care of.
http://www.manzanitamicro.com/products? ... _id=41Plus
The only shortcoming of the Manzanita Smart Box thus far is that it can't shake hands with my SPX-brand EVSE. No problems yet with Blink, Chargepoint, SemaConnect..

So, an Open EVSE Spider Box is now on the project list!
2012 i-SE "MR BEAN" 105,400 miles
2000 Mazda Miata EV, 78 kW, 17 kWh
1983 Grumman Kurbwatt EV,170 kW, 32 kWh
1983 Mazda RX-7 EV 43 kW 10 kWh
1971 "Karmann Eclectric" EV 240 kW 19 kWh
1965 Karmann Ghia Cabriolet

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