LeafDD - Dash Display for Leaf

[GregH]

Just a few notes and observations..
I don't think the trickle charge makes much difference..(?) Jason, perhaps getting down towards empty surprised the LBC and it readjusted your capacity down.. then brought it back after seeing the capacity from the charge? Dunno.
If the LBC has made a decision to discharge several cells then a subsequent trickle charge would give it time to do the balancing.. but so would driving or charging at L2. I don't know exactly when the balancing decisions are made but having observed dozens of "full" charges that brought on balancing and a few 80% charges that did not, my inclination would be that the decision is made at the end of a full charge.. can't say for sure about 80%. Also can't say for sure if it's looking at the cell voltages at low SOCs to determine balancing or just "top" balancing based on the voltages at the end of charge.
Based on what I've seen of the OBC on 2011/12s, the charger can be commanded a current level in steps of 1.0A. We can see this in the CAN data and are using it to help control the Brusa. I don't know if it's a command from the LBC to the OBC or feedback from the OBC to the LBC, but it is in 1.0A increments. The 2013 integrated charger can certainly go at much finer increments and as many have witnessed.. it can dwell at really low currents for a long time (20-40minutes).
I had forgotten about the "charger turns on again after 4 hours" thing.. two years ago I wrote code for the old EDriveDD to specifically look for events where the charger came on later (a sign of balancing).. but never saw it. Perhaps the balancing strategy has evolved over the years and could be different depending on which version of software you have?
Since the LBC runs on the 12V battery which is unaided by the DCDC while the car is off, I'm guessing they decided not to keep the LBC alive to perform and monitor balancing while the car is off. As I mentioned before, the prescribed mAhs to be discharged can be taken from the cells at any time, might as well do it when the LBC would normally be on (charging, driving). Perhaps on the original 2011 software they actually kept it on for 4 hours to balance, then turned charging back on? Like I said, I've never seen this in my 2011 or 2012.

 

[TonyWilliams]

Would be nice if there was an easy way to turn the current down to an arbitrary level while charging - right now you need a recent EVSEupgrade or build an OpenEVSE to do so.

You could also do it with a Tesla Model S UMC (with a J1772 plug added on);

Yes, it has a dedicated fourth pin on the wall plug: 2 "hot" (Line 1&2), 1 ground and one amp signal.

When you attach the respective $45 plug, it will automatically use the following amperage:

.............................................VOLTS / AMPS................kW
NEMA 5-15 .......Standard Outlet 110 V / 12 A...... 1.4 kW
NEMA 14-50......RVs and Camps. 240 V / 40 A...... 9.6 kW
NEMA 6-50 .......Welding Equip... 240 V / 40 A...... 9.6 kW
NEMA 10-30......Older Dryers...... 240 V / 24 A...... 5.8 kW
NEMA 14-30......Newer Dryers..... 240 V / 24 A...... 5.8 kW


Or you could install a simple switch for various amperage outputs from 6 amps to 40 amps.


The small pin is the Amperage Control:

Here is the UMC owner's manual:

https://www.teslamotors.com/sites/default/files/blog_attachments/ms_mobile_connector_guide.pdf" onclick="window.open(this.href);return false;

 

[DaveEV]

It seems that '13 cars spend a lot more time trickling energy into the pack - they will quickly charge up to 95% or so but then taper off the charge current significantly and spend a good hour to charge from 97-100% with just a trickle going into the pack.

I thought the P upgrade helped with this? I know mine will sit for sometime or a good while trying to balance

Are you sure? How long is a "good while"? As GregH mentions the '13 seems to be able to ramp down to a much lower power level and it uses that as an opportunity to squeeze as much energy into the pack as possible when charging to 100%. I've never seen that type of behavior on my car - no more than 15-20 minutes from when it starts ramping down power from 3.3 kW to turning off on a 100% charge.

Would be nice if there was an easy way to turn the current down to an arbitrary level while charging - right now you need a recent EVSEupgrade or build an OpenEVSE to do so.

I do have both but I don't know if its something the Leaf wants to see as a Trickle? (120v input) or just a reduced PILOT sig on a 240v line. It knows the difference..

But again, I'm not the "MASTER" on this side... does the Leaf balance differently or must know the difference on a 6a 240 pilot and a 15a 120 Trickle?

For this particular situation where we are simply trying to give the car more time to balance, 240V/6A or 120V/12A is going to be the same. The OBC might be more efficient running on 240V, but that's it. If you really want to make sure you give the car a lot of time to trickle, you're going to want to use 120V and 6-8A. Combined with the overhead of running the cooling pumps, charging from 80-100% should take a good 8-12 hours.

I don't know exactly when the balancing decisions are made but having observed dozens of "full" charges that brought on balancing and a few 80% charges that did not, my inclination would be that the decision is made at the end of a full charge.. can't say for sure about 80%.

For sure charging to 100% seems to induce more balancing shunts compared to 80%. At the very least, it seems that cars that are regularly charged to 100% tend to have much tighter CP voltages.

Also can't say for sure if it's looking at the cell voltages at low SOCs to determine balancing or just "top" balancing based on the voltages at the end of charge.

Yeah, hard to say given that one can see shunts turning on at just about any SOC.

I had forgotten about the "charger turns on again after 4 hours" thing.. two years ago I wrote code for the old EDriveDD to specifically look for events where the charger came on later (a sign of balancing).. but never saw it. Perhaps the balancing strategy has evolved over the years and could be different depending on which version of software you have?

I've never seen it, either, though I don't think I've ever let my car sit for a while at 100% without any timers set.

Since the LBC runs on the 12V battery which is unaided by the DCDC while the car is off, I'm guessing they decided not to keep the LBC alive to perform and monitor balancing while the car is off. As I mentioned before, the prescribed mAhs to be discharged can be taken from the cells at any time, might as well do it when the LBC would normally be on (charging, driving). Perhaps on the original 2011 software they actually kept it on for 4 hours to balance, then turned charging back on? Like I said, I've never seen this in my 2011 or 2012.

Good theory. I presume the LBC needs to be on for the shunts to be active?

 

[GregH]

Since the LBC runs on the 12V battery which is unaided by the DCDC while the car is off, I'm guessing they decided not to keep the LBC alive to perform and monitor balancing while the car is off. As I mentioned before, the prescribed mAhs to be discharged can be taken from the cells at any time, might as well do it when the LBC would normally be on (charging, driving). Perhaps on the original 2011 software they actually kept it on for 4 hours to balance, then turned charging back on? Like I said, I've never seen this in my 2011 or 2012.

Good theory. I presume the LBC needs to be on for the shunts to be active?

Just a theory.. Since I see it turn on the shunts over the course of a few seconds after powering up I believe the shunts are off when power is off. The lithium BMSs I designed for the EDrive Prius had what I thought was a pretty slick way to balance with power off.. I had opto isolated signals going to latches that were powered by the cells to be balanced.. When latched, a FET would discharge about 80mA through a (low) power resistor as well as another resistor and LED.. so you could see which cells were balancing from the LEDs. In retrospect maybe not a great idea.. If the controller on the other side of the opto failed, a shunt could be left on indefinitely (or at least to a voltage low enough where the latch would fail). In practice I never saw this happen, but anything is possible.

With few exceptions it seems standard practice now is that when the vehicle is off, there is NOTHING loading the high voltage pack. If you let the car sit for a years unattended the 12V lead acid battery might die but other than the extremely low lithium self discharge, the high voltage pack would remain untouched.

 

[HighDesertDriver]

Hello,
I've been watching to see if the balancing would take care of my #16 cell. Once it looked like it had come up in voltage but alas that was only one day and it's back in the low pole position.

My cell-pair #48 has always been low since I started tracking it in mid June: usually about 10-30 mV below average. Nissan won't fix it unless it sets an error code.

#21 seem to be the predominant "weak" actor in our's, but it always one of only four neighbors (21, 22, 23, or 24). The difference when operating the car is usually 20-30 mV with occasional excursions to ~35. Anyone have an idea of what the acceptable limit is?

 

[LEAFfan]

It seems that '13 cars spend a lot more time trickling energy into the pack - they will quickly charge up to 95% or so but then taper off the charge current significantly and spend a good hour to charge from 97-100% with just a trickle going into the pack where a '11-12 will quickly taper off in 15 minutes before stopping.

Mine quickly charges to 98%, then trickles for at least an hour to 100%. I've only charged to 100% once because I realized that there is no more capacity added after a full 98%. If I stop it when the LB App shows no more Gids, kW hs, W hs, etc. going into the pack, I will have one bubble and the second appears shortly after driving.

 

[bowthom]

Hello,
According to the Nissan info IIRC the battery has to be below a certain state of charge and the problem cell has to be a defined percentage below the average (or mean) battery voltage. I forget the specifics, I'll re-read the manual and edit this post later.

 

[TickTock]

Hello,
According to the Nissan info IIRC the battery has to be below a certain state of charge and the problem cell has to be a defined percentage below the average (or mean) battery voltage. I forget the specifics, I'll re-read the manual and edit this post later.

The procedure you are looking for the the CVLI (cell voltage loss inspection) and is only valid when the minimum cell voltage is below 3712mV.
http://www.mynissanleaf.com/viewtopic.php?f=44&t=12789&start=212

 

[bowthom]

Hello,
FYI, I turned on my Leaf when the wife got home at 84 gids AND...... the car was balancing cells if my LeafDD is to believed.

 

[Goodtohave]

So a bit off the recent topics but after a few months with my DD the weather cooled down and my Health which was 93% is now 98.98%.

The car is only 3 months old but is a 2012 and sat around for a while before I bought it.

The battery seem to like a few nights of 10degrees celsius.

 

[essaunders]

I've seen the accolades for LeafDD in this thread. I've also read good things about (now) LeafSpy. Is there a discussion anywhere comparing the merits of these two tools? I'm in the position of wanting some extra info - but need to purchase either a LeafDD or a full Android + CANBUS BT device and I'm looking for recommendations.

 

[Digitalxrayguy]

That's a good question and I'm not aware of a comparison but there's a lot of stuff in this forum I'm still learning about. But, I did want to put my two cents in as a thought because I saw a Google Plus (Leaf Community) comment about the Android App and the BT adapter. It all looks great but an advantage to the LeafDD is it's always there and you don't have to think about it. I was picturing using the phone app and having to find a good "holder" for the phone and dedicating it to the app while driving. Of course phone calls could be an easy and intuitive interruption but what if you wanted to use Waze and be rerouted for traffic issues? Can't do both at the same time. Having a dedicated device off to the left out of normal field of view for driving is strongly my preference. Good luck with your choice and purchase. -rb

 

[TomT]

If I could only have one device, I'd have a hardwired one because of the mounting, power and driving issues... In actuality, I have both a hardwired unit (Lincomatic V2, which I bought long before the LeafDD existed) and Leaf Spy because each offers some functionality that the other does not. Doing this, of course, does require an OBDII splitter and one must be careful not to use both devices in an active mode simultaneously as that can cause a data error... Price-wise, if you already have an Android device, Leaf Spy will be cheaper. If not, than it is pretty much a draw. Both will do an excellent job for you, it is more a matter of individual user preference. If *I* was starting over today, I'd have both the DD and Leaf Spy...

That's a good question and I'm not aware of a comparison but there's a lot of stuff in this forum I'm still learning about. But, I did want to put my two cents in as a thought because I saw a Google Plus (Leaf Community) comment about the Android App and the BT adapter. It all looks great but an advantage to the LeafDD is it's always there and you don't have to think about it. I was picturing using the phone app and having to find a good "holder" for the phone and dedicating it to the app while driving. Of course phone calls could be an easy and intuitive interruption but what if you wanted to use Waze and be rerouted for traffic issues? Can't do both at the same time. Having a dedicated device off to the left out of normal field of view for driving is strongly my preference. Good luck with your choice and purchase. -rb

 

[TickTock]

If both devices are operating correctly, there should be no issues (lower priority messages automatically yield to higher). I have used CANary along side LeafSpy without issues (and both use active messaging).

one must be careful not to use both devices in an active mode simultaneously as that can cause a data error

 

[TomT]

I remember a discussion about this on the Battery App Beta thread some time back indicating that there could be a problem with active devices under some circumstances... Did I misinterpret that? Myself, I have never had an issue using Lincomatic V2B3 and Leaf Spy simultaneously in any mode...

If both devices are operating correctly, there should be no issues (lower priority messages automatically yield to higher). I have used CANary along side LeafSpy without issues (and both use active messaging).

one must be careful not to use both devices in an active mode simultaneously as that can cause a data error

 

[Mx5racer]

When I charge to 80%
I get 9 bars and the display shows 184

When I charge to 100%
And then drive down to 184 I still have 11 bars

Why?
I would assume that the bars would match and 184 would always be 9 bars

 

[GregH]

When I charge to 80%
I get 9 bars and the display shows 184

When I charge to 100%
And then drive down to 184 I still have 11 bars

Why?
I would assume that the bars would match and 184 would always be 9 bars

Obnoxious hysteresis?
From my personal experience the energy remaining "bars" are almost useless... The fact that you can lose a bar just by cycling power makes it seem to me that it's just a way to freak people out when they're getting relatively low on charge. I find the Guess-o-meter much more useful than the energy bars. Of course raw Gids puts all the Leaf instrumentation to shame.

 

[garygid]

It should not be 2 bars different, only one bar different,
due to the normal hysteresis. Two bars different
at the same resl-GID value is rather strange, I think.

 

[bowthom]

Hello,
I'm pretty confused with the numbers coming out of the leaf as portrayed by the Leaf DD.
Tonight it shows 80% health at 59.73 Ah. Just a couple of weeks ago it showed 91% health at 62.97 Ah.
Something is wonky.

 

[stjohnh]

Hello,
I'm pretty confused with the numbers coming out of the leaf as portrayed by the Leaf DD.
Tonight it shows 80% health at 59.73 Ah. Just a couple of weeks ago it showed 91% health at 62.97 Ah.
Something is wonky.

Most of these values have been derived by smart people doing reverse engineering, unfortunately the "H" value, commonly called "Health" is probably only related to actual battery "health" in a convoluted way. It would much better be called "H-factor" until it is better understood. However the name "Health" for this value has become entrenched and won't likely change.