User avatar
gbarry42
Posts: 888
Joined: Mon Jan 10, 2011 5:48 pm
Delivery Date: 06 May 2011
Location: Moonlight Beach

Re: Tow to recharge

Fri Jan 27, 2012 4:20 pm

Haven't we been here before? Oh, yes, here you go: http://www.mynissanleaf.com/viewtopic.p ... t=0#p95615" onclick="window.open(this.href);return false;

Regen is limited to 30kW -- look at your energy gauge.

30kW is 40 HP -- that comes directly from the guy that's towing you.
And there goes the first capacity bar! At 24,000 mi on 9/9/2013.
Second bar at 30,500 mi on 2/7/2015.

User avatar
Ingineer
Posts: 2741
Joined: Fri Oct 15, 2010 1:09 pm
Delivery Date: 13 Jul 2011
Leaf Number: 6969
Location: Berkeley, California
Contact: Website

Re: Tow to recharge

Mon Jan 30, 2012 10:41 pm

Regen is not limited to 30kW. I've seen regen as high as almost 42kW. Here's a screenshot:

Image

Regen is limited by the Battery ECU based on factors such as battery SOC, Temperature, etc.

And yes, you can tow the Leaf and recharge it. In fact, There is a video of it on Youtube. Not recommended, and may void your warranty, but it does work. If you towed a Leaf until it was (near) fully recharged, Regen would simply cease as the Battery ECU lowers the Regen possible parameter sent to the main ECU.

-Phil
Easily Learn Electricity HERE! - - - - Website: http://evseupgrade.com/[/size] - - - - Like us on Facebook: EVSE Upgrade

User avatar
garygid
Gold Member
Posts: 12464
Joined: Wed Apr 21, 2010 8:10 am
Delivery Date: 29 Mar 2011
Leaf Number: 000855
Location: Laguna Hills, Orange Co, CA

Re: Tow to recharge

Tue Jan 31, 2012 9:45 am

Have you identified "Regen Possible" (Amps or kW), or
"Regen Actual" (Amps or kW) in the EV-CAN messages?
See SOC/GID-Meter and CAN-Do Info
2010 Prius, now for sale
2011 LEAF, sold in 2015
2018 Tesla Model 3
2014 Tesla S, Model 3 in 2019
PU: SDG&E
Solar PV: 33 x 225W -> 7 kW max AC
To Sell: X-treme 5000Li EV motorcycle

User avatar
TimeHorse
Gold Member
Posts: 999
Joined: Thu May 13, 2010 4:40 am
Delivery Date: 02 Nov 2011

Re: Tow to recharge

Tue Jan 31, 2012 10:15 am

Stupid question: to regen we need it in drive; fine. So we hook up the tow and turn on the car (towed from the back where there is no hook or is the regen on the rear tires like on the Prius IIRC) doesn't the car try to generate that stupid 5 MPH idle wasting my traction battery?

Again, sorry to be so naïve just when Ingineer talks, I know we're gonna get answers! :)
RIP CO2 Fre, 27 months, 42,282 mi & 11 bars.
unAmerican Job & Nissan's Rapid Depreciation cost $20,000!
5 hours on the road daily w/o Charge at Work on 100%.

Long Live CO2 Fre, Maxed 2013 SL, 20,000 mi/yr lease.
http://aecn.timehorse.com/" onclick="window.open(this.href);return false;

User avatar
garygid
Gold Member
Posts: 12464
Joined: Wed Apr 21, 2010 8:10 am
Delivery Date: 29 Mar 2011
Leaf Number: 000855
Location: Laguna Hills, Orange Co, CA

Re: Tow to recharge

Tue Jan 31, 2012 2:13 pm

If one were to do this (not advised),
Tow from the front, with front wheels on the ground, car READY.
The front wheels give the regen, not the back.
See SOC/GID-Meter and CAN-Do Info
2010 Prius, now for sale
2011 LEAF, sold in 2015
2018 Tesla Model 3
2014 Tesla S, Model 3 in 2019
PU: SDG&E
Solar PV: 33 x 225W -> 7 kW max AC
To Sell: X-treme 5000Li EV motorcycle

User avatar
TonyWilliams
Posts: 10090
Joined: Sat Feb 19, 2011 1:48 am
Location: San Diego
Contact: Website

Re: Tow to recharge

Tue Jan 31, 2012 2:26 pm

garygid wrote:If one were to do this (not advised),
Tow from the front, with front wheels on the ground, car READY.
The front wheels give the regen, not the back.
Which also means that if you "kill" the battery (the car shuts down automatically due to low battery), towing it won't help, because it won't go in gear. Only neutral and park.

Don't kill the car!!

DaveinOlyWA
Posts: 14107
Joined: Sat Apr 24, 2010 7:43 pm
Delivery Date: 16 Feb 2018
Leaf Number: 314199
Location: Olympia, WA
Contact: Website

Re: Tow to recharge

Tue Jan 31, 2012 4:36 pm

TonyWilliams wrote:
garygid wrote:If one were to do this (not advised),
Tow from the front, with front wheels on the ground, car READY.
The front wheels give the regen, not the back.
Which also means that if you "kill" the battery (the car shuts down automatically due to low battery), towing it won't help, because it won't go in gear. Only neutral and park.

Don't kill the car!!
even if you did "apparently" kill the car. in most cases if you let it sit 15 minutes, some charge will come back. hopefully enough to boot the system.

i am seeing 1-4 GID coming back on nearly every power up.
2011 SL; 44,598 miles. 2013 S; 44,840 miles.2016 S30 deceased. 29,413 miles. 2018 S40; 15,000 miles, 478 GIDs, 37.0 kwh 109.81 Ahr , SOH 94.61, Hx 120.15
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

User avatar
hgoudey
Forum Supporter
Posts: 55
Joined: Fri Jul 08, 2011 6:39 pm
Delivery Date: 03 Jul 2011
Leaf Number: 5132
Location: El Cerrito, CA

Re: Tow to recharge

Tue Jan 31, 2012 7:57 pm

I hate to say it, but does this mean the the lowest budget, lowest tech. version of a stationary L3 charging station would be a lousy ~60hp ICE driving some floor mounted rollers ala a chassis dynamometer (but without out the need for the expensive power measurement bits of the dyno) to pump 30-40 kW into the battery using regen? That's one way around the limitations of the 3.6kW charger. It would be frowned upon by Nissan to be sure, but I wonder if they could legally void the warranty, since a long steep downhill road is an identical experience from the traction system's perspective. The roller system could all fit on a portable truck which would also probably be a way to weasel around stationary engine regulations. For an off the shelf solution with extra crazy points, picture driving the front wheels of the Leaf in the tire crotch of a fenderless dual axle truck on jack stands. The tire track width would almost certainly not match, but with any luck the interior pair on a 18 wheeler tractor might just match a smaller car, and you could use the cargo ship tie down hooks on the Leaf to anchor it from popping off the driven wheels (see, safety first).

It would at least be amusing to see the well to wheels efficiency and CO2 impact of the engine driven roller approach vs. various grid power plants with all the associated losses, etc. I don't like the idea of resorting to hydrocarbons, though (even if they could be a magic sustainable biofuel), so here's what it would look like if you installed a municipal style water tower over the roller charging station to power it in a pumped hydro storage fashion. Dump 100 liters/sec from a tank elevated 40 meters and you get 40 kW of water power to run the rollers directly off of a Pelton wheel (back to 19th century technology!). Of course you need a 1800 cubic meter (475,510 gallon) tank top and bottom to hold enough water for a 30 min charge at 40kW which is no modest infrastructure for one lousy L3 charge. They you have to figure out where you're going to get your power to recharge the 20 kWhs of water back up the tower and how fast you're going to do it (duty cycle). You could buy renewables off the grid, or have on site solar/wind, but it looks pretty clear that the amount of infrastructure involved doesn't justify the modest service provided. Maybe it would work in New England where they could resurrect all those old mill water power sites as EV charging stations.

Howdy Goudey

User avatar
TonyWilliams
Posts: 10090
Joined: Sat Feb 19, 2011 1:48 am
Location: San Diego
Contact: Website

Re: Tow to recharge

Tue Jan 31, 2012 9:28 pm

DaveinOlyWA wrote:
even if you did "apparently" kill the car. in most cases if you let it sit 15 minutes, some charge will come back. hopefully enough to boot the system.

i am seeing 1-4 GID coming back on nearly every power up.

When it auto shuts down, it won't power back up without significant charge.

BTDT.

kmcmahan
Gold Member
Posts: 11
Joined: Fri Jan 06, 2012 8:43 am
Delivery Date: 21 Dec 2011
Leaf Number: 6072

Re: Tow to recharge

Fri Mar 02, 2012 1:40 pm

sorry about the misleading terminology. I was in gear going downhill and the energy page showed that I was doing a lot of regenerating

Return to “Engineering”