RottenMutt
Posts: 14
Joined: Tue Jan 28, 2014 12:10 pm
Delivery Date: 22 Jan 2014
Leaf Number: 423504

Dead Traction Battery to Full Charge

Sat Feb 08, 2014 7:40 pm

I went out today with the goal of hitting turtle, well a few seconds after turtle the traction battery cut off the drive motor at 4 GIDs. The temperature was about 56 F outside and I had the defroster and rear window defroster on to help deplete the battery. I suppose that is why I had 4 GID's on the meter with a dead car (I did give it full throttle after turtle to see how fast i could go which was about 40 mph). Lucky for me I coasted to the stop sign and the eVgo DC charger was 100 feet or so away! The car really pushes easy! First Charge completed at 91% capacity with 21.20 KWh added, second charge completed at 1.543 kWh added at 97% Charged for a total of 22.74 kWh. The DC charger charged at 125 amps @ 391.5 volts which would be 48.9 kW until about 60% charge level and then started to ramp down.

my usual GIDs after charging is about 265.
1/29/2014: S 97.25 C 60.5277 H 92.87 GID 263 V 395
2/08/2014: S 97.25 C 61.6787 H 95.10 GID 268 V 396
2013 Leaf S, mfg date 11/13

stjohnh
Posts: 363
Joined: Tue Jun 18, 2013 4:27 pm
Delivery Date: 10 Jun 2013
Leaf Number: 409675
Location: Palo Alto, CA

Re: Dead Traction Battery to Full Charge

Sat Feb 08, 2014 8:57 pm

RottenMutt wrote:I went out today with the goal of hitting turtle, well a few seconds after turtle the traction battery cut off the drive motor at 4 GIDs. The temperature was about 56 F outside and I had the defroster and rear window defroster on to help deplete the battery. I suppose that is why I had 4 GID's on the meter with a dead car (I did give it full throttle after turtle to see how fast i could go which was about 40 mph). Lucky for me I coasted to the stop sign and the eVgo DC charger was 100 feet or so away! The car really pushes easy! First Charge completed at 91% capacity with 21.20 KWh added, second charge completed at 1.543 kWh added at 97% Charged.

my usual GIDs after charging is about 265.
1/29/2014: S 97.25 C 60.5277 H 92.87 GID 263 V 395
2/08/2014: S 97.25 C 61.6787 H 95.10 GID 268 V 396


You haven't asked a question, but here are a couple of comments on your experience: The computer in your car monitors the battery and protects it from damage, in this case damage occurs if the voltage goes too low. The impedance of the cells goes way up as the voltage falls below 3.2 volts. Turtle usually occurs at about 3.0 volts. When you press firmly on the "gas" pedal you are putting maximum load on the battery, causing the voltage to drop dramatically, the computer senses this and turns off your car to protect the battery. You can go farthest by pressing gently on the accelerator pedal and driving very slowly.

Most Leafs built May 2013 and later have very non-linear Gid curves, I strongly recommend you don't try to use Gids to judge battery or range capacity.
Blessings,
Holland

2 LEAFS, bought 1 week apart. 2013 S for me, 2013 SV is wife's. Both manufactured May 2013. I lost first bar at 36,000. Wife still has all bars at 50,000.

RottenMutt
Posts: 14
Joined: Tue Jan 28, 2014 12:10 pm
Delivery Date: 22 Jan 2014
Leaf Number: 423504

Re: Dead Traction Battery to Full Charge

Sat Feb 08, 2014 10:10 pm

stjohnh wrote:You haven't asked a question, but here are a couple of comments on your experience: The computer in your car monitors the battery and protects it from damage, in this case damage occurs if the voltage goes too low. The impedance of the cells goes way up as the voltage falls below 3.2 volts. Turtle usually occurs at about 3.0 volts. When you press firmly on the "gas" pedal you are putting maximum load on the battery, causing the voltage to drop dramatically, the computer senses this and turns off your car to protect the battery. You can go farthest by pressing gently on the accelerator pedal and driving very slowly.

Most Leafs built May 2013 and later have very non-linear Gid curves, I strongly recommend you don't try to use Gids to judge battery or range capacity.


In all this was a good experience. So you're confirming what i suspected, if i had turned off the front and rear window defrosters and been gentler on the throttle i could have gone a lot further and could have depleted the last few GIDs. It is useful to know how far u can go before it shuts down! The last 20 GID's just didn't want to go away, as you say not linear!
2013 Leaf S, mfg date 11/13

stjohnh
Posts: 363
Joined: Tue Jun 18, 2013 4:27 pm
Delivery Date: 10 Jun 2013
Leaf Number: 409675
Location: Palo Alto, CA

Re: Dead Traction Battery to Full Charge

Sun Feb 09, 2014 8:22 am

If you drive at 4 mi/kwh or better, you can use the formula soc-4=distance to turtle, where soc is from your meter/LeafSpy (not dash soc) to predict your remaining range. Works down to 11% soc (7 mi to turtle). The last fuel bar disappears at 7mi left. If you drive very close to turtle (ie no fuel bars) the minimum cell voltage is the most accurate predictor of remaining range.

The above is only valid for newer Leafs with capacity in 60 ahr range.
Blessings,
Holland

2 LEAFS, bought 1 week apart. 2013 S for me, 2013 SV is wife's. Both manufactured May 2013. I lost first bar at 36,000. Wife still has all bars at 50,000.

GroundHog
Posts: 24
Joined: Sun Feb 02, 2014 3:11 pm
Delivery Date: 03 Dec 2013

Re: Dead Traction Battery to Full Charge

Fri Feb 14, 2014 12:03 pm

stjohnh wrote:If you drive at 4 mi/kwh or better, you can use the formula soc-4=distance to turtle, where soc is from your meter/LeafSpy (not dash soc) to predict your remaining range. Works down to 11% soc (7 mi to turtle). The last fuel bar disappears at 7mi left. If you drive very close to turtle (ie no fuel bars) the minimum cell voltage is the most accurate predictor of remaining range.

The above is only valid for newer Leafs with capacity in 60 ahr range.


I have a 2013 with 66 ahr, BUT with a bad module see http://www.mynissanleaf.com/viewtopic.php?f=30&t=15768. I've been trying to show my dealer that this module does in fact decrease the range of my leaf because they are saying my range is fine and thus there is nothing wrong with the battery. Yes I know the manual is clear about what constitutes a bad module, but they are insisting that my range is fine and thus no repair is needed.

stjohnh has noted something that perhaps I can point out to them. He said that when the car turtles, it is really the lowest cell voltage that matters. What cell voltage have people measured this should be and what was the average voltage at this point? In my car, I hit turtle when my bad cell pair is 2.70 V and the average voltage is about 3.20. Is the average cell voltage for most people closer to 3.00 at turtle than I'm getting. Or do people get turtle at 2.7 V like I do. That would be something to point out to my shop.

The other thing is that when I am charged up over 50%, the %SOC on Leafspy is about the same as the %GIDs. But these numbers start to deviate below 50% as shown below:

100% charge - 283 GIDs - 97% SOC (Leafspy)
80% charge - 225 GIDs - 79% SOC (Leafspy)
~50% - 140 GIDs - 53% SOC (Leafspy)
LBW - 50 GIDs - 25% SOC (Leafspy)
VLBW - 25 GIDs - 18% SOC (Leafspy)
Turtle - 6 GIDs - 9.7% SOC (LeafSpy)

I think the GIDs that I get at each of these points is pretty normal, but are my %SOCs as measured by LeafSpy high at the low end, and perhaps low at the high end? This would be another indicator that my battery has low capacity.

If I watch my %SOC on LeafSpy, when I'm down to 11%, even with very easy driving, I've only got about 1 mile left to turtle. stjohnh says that I should have 7 miles left. So here is a loss of about 6 miles range.

I'd really like some supporting data to take to my shop to help my case. Thanks

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