Discuss data from the LEAF Battery app, and Comparisons

[TickTock]

I re-parsed an old log from March 2012 where I was experimenting with the 79b messages (but not understanding the results at the time) and was able to extract my SOH and Ah from it at 87.7% and 59.1Ah. Lost my first bar two months later. Now, 15 months later, I am reading 63.4% and 46.0Ah. At that time, I was getting 254 gids on a 100% charge, pulling ~20.4kWh from the wall. Now I am pulling 18.8kWh from the wall to reach 196 gids on a 100% charge.

 

[edatoakrun]

I re-parsed an old log from March 2012 where I was experimenting with the 79b messages (but not understanding the results at the time) and was able to extract my SOH and Ah from it at 87.7% and 59.1Ah. Lost my first bar two months later. Now, 15 months later, I am reading 63.4% and 46.0Ah. At that time, I was getting 254 gids on a 100% charge, pulling ~20.4kWh from the wall. Now I am pulling 18.8kWh from the wall to reach 196 gids on a 100% charge.

Thanks for digging up that old info, and for collecting it in the first place.

What SOC are those recharge kWh measured from, Tick Tock- turtle?

Much difference in the battery temperatures between the two charge sessions?

So, if I understand you correctly, it looks like an ~8% reduction in recharge capacity between the first to the second events is reported as a ~28% percentage reduction in Ah, and a ~27% reduction in ("true", I assume) gids?

 

[Boomer23]

kWh used to recharge from Turtle was 25.3.

CAP% was up to 96.16% and AH was up to 63.71.

It looks like the BMS and the pack are getting to know each other better and the car is learning. I'm encouraged.

I went away on vacation for five days and left the 2013 LEAF in the garage with 7 bars charge. Came back and checked the LB App. AH is now up to 65.33 and CAP at 98.61%. About 40% of the cell pair histogram bars were red at the time of today's reading. Lots of balancing happening in the pack, even without having charged or being driven for five days.

I'll be interested to see the True Gids at 100% charge tomorrow morning.

Recall that the first AH reading that I got at the dealer when I picked up the car was 60.89. It's really interesting (and, of course reassuring) to see the pack gaining this much AH over the week and a half that I've had it. The 25.3 kWh measured from the wall to recharge it from Turtle is also reassuring news that I seem to have full capacity.

Just to finish my little tale, True Gids this morning were 284 and 101%!!!!

Just goes to show that AH readings for a new car can be misleading.

 

[dm33]

Just to finish my little tale, True Gids this morning were 284 and 101%!!!!

Just goes to show that AH readings for a new car can be misleading.

My now 4 week old 2013 Leaf has been very consistent every time I've ever checked at around 95.5%. No dramatic drop nor rise.

Would driving it to turtle help reset the BMS? Apple tells their laptop consumers to periodically run down their battery all the way to shutdown, then recharge to 100% from there. I'm sure its not good for the battery, but they use it to calibrate the batteries capacity.

 

[jguenst]

since it has not changed have you taken your leaf back to have checked ?

 

[TickTock]

I re-parsed an old log from March 2012 where I was experimenting with the 79b messages (but not understanding the results at the time) and was able to extract my SOH and Ah from it at 87.7% and 59.1Ah. Lost my first bar two months later. Now, 15 months later, I am reading 63.4% and 46.0Ah. At that time, I was getting 254 gids on a 100% charge, pulling ~20.4kWh from the wall. Now I am pulling 18.8kWh from the wall to reach 196 gids on a 100% charge.

Thanks for digging up that old info, and for collecting it in the first place.

What SOC are those recharge kWh measured from, Tick Tock- turtle?

Much difference in the battery temperatures between the two charge sessions?

So, if I understand you correctly, it looks like an ~8% reduction in recharge capacity between the first to the second events is reported as a ~28% percentage reduction in Ah, and a ~27% reduction in ("true", I assume) gids?

Most of my charges start from 40-60 gids with the occasional < 25 (VLBW). I've only brought it to turtle twice in it's life - both for experimentation. However, I extrapolate to 0 gids to compute my dead-100% charge so some error in that due to any non-linearities in the gid/kWh curve but just for that portion below 40-60.

Yes, I find your analysis interesting, too. Could it be charging efficiency diminishes significantly with battery age? My range has dropped about 25% over that same period (from ~75 miles to ~55 miles) however, part of that can be attributed to my new tires which I estimate dropped my efficiency ~8%.

 

[GregH]

I re-parsed an old log from March 2012 where I was experimenting with the 79b messages (but not understanding the results at the time) and was able to extract my SOH and Ah from it at 87.7% and 59.1Ah. Lost my first bar two months later. Now, 15 months later, I am reading 63.4% and 46.0Ah. At that time, I was getting 254 gids on a 100% charge, pulling ~20.4kWh from the wall. Now I am pulling 18.8kWh from the wall to reach 196 gids on a 100% charge.

Ouch! :shock: That sucks.. In a somewhat morbid way I'll be interested to hear what kinds of battery temps you see this weekend during our SW heatwave..

Just to finish my little tale, True Gids this morning were 284 and 101%!!!!
Just goes to show that AH readings for a new car can be misleading.

Nice!!! Good to know that even in this heat the BMS can still giveth and not just taketh away!
101% what? How many Ahs is that? I'm guessing over 67.. It'd be interesting to see the health reading.

 

[TickTock]

I re-parsed an old log from March 2012 where I was experimenting with the 79b messages (but not understanding the results at the time) and was able to extract my SOH and Ah from it at 87.7% and 59.1Ah. Lost my first bar two months later. Now, 15 months later, I am reading 63.4% and 46.0Ah. At that time, I was getting 254 gids on a 100% charge, pulling ~20.4kWh from the wall. Now I am pulling 18.8kWh from the wall to reach 196 gids on a 100% charge.

Ouch! :shock: That sucks.. In a somewhat morbid way I'll be interested to hear what kinds of battery temps you see this weekend during our SW heatwave..

I have a swamp cooler in my garage so the battery temp is in the mid 80's when I leave (garage is in the mid 70's but I END charge so the pack just finished charging when I leave). I park in the shade at work and, even though ambient is >110, my pack temp is in the low-mid 90's when I leave work and is usually just crossing 100 when I get home 35 minutes later.

 

[edatoakrun]

...Could it be charging efficiency diminishes significantly with battery age? My range has dropped about 25% over that same period (from ~75 miles to ~55 miles) however, part of that can be attributed to my new tires which I estimate dropped my efficiency ~8%.

Any reduction in the charging efficiency of the battery pack would result in heat generated in the pack during the charge, would it not?

So, shouldn't even a relatively slight reduction in efficiency (which may be expected, as the battery pack ages) be observable as increased battery heating during the charge?

I'd think you would surely have noticed the ~ three kWh (?) of battery heating, caused by that significant a reduction in charging efficiency.

How are you determining that your range has dropped ~25%, or ~17% (?) as adjusted for tires?

 

[GregH]

I re-parsed an old log from March 2012 where I was experimenting with the 79b messages (but not understanding the results at the time) and was able to extract my SOH and Ah from it at 87.7% and 59.1Ah. Lost my first bar two months later. Now, 15 months later, I am reading 63.4% and 46.0Ah. At that time, I was getting 254 gids on a 100% charge, pulling ~20.4kWh from the wall. Now I am pulling 18.8kWh from the wall to reach 196 gids on a 100% charge.

Ouch! :shock: That sucks.. In a somewhat morbid way I'll be interested to hear what kinds of battery temps you see this weekend during our SW heatwave..

I have a swamp cooler in my garage so the battery temp is in the mid 80's when I leave (garage is in the mid 70's but I END charge so the pack just finished charging when I leave). I park in the shade at work and, even though ambient is >110, my pack temp is in the low-mid 90's when I leave work and is usually just crossing 100 when I get home 35 minutes later.

I have a very similar setup.. I leave the garage door open 8-10 inches and have a small fan blow outside air under the car. My charger kicks in between 3 and 5am so it starts heating up again and I'm lucky if I'm still at 5TB (25C 77F) when I leave. My morning commute is usually cool enough that the heat generated by driving is offset by the ambient airflow over the car so I usually land at work with the same temps as when I left. I try to keep it in the shade but ambient temps and any work place charging take their toll. Today will be different though.. This morning I left at 31C (88F) landed at work with 32C (90F) and would be shocked if I can make it home without hitting 35C (95F).

 

[GregH]

...Could it be charging efficiency diminishes significantly with battery age? My range has dropped about 25% over that same period (from ~75 miles to ~55 miles) however, part of that can be attributed to my new tires which I estimate dropped my efficiency ~8%.

Any reduction in the charging efficiency of the battery pack would result in heat generated in the pack during the charge, would it not?

So, shouldn't even a relatively slight reduction in efficiency (which may be expected, as the battery pack ages) be observable as increased battery heating during the charge?

I'd think you would surely have noticed the ~ three kWh (?) of battery heating, caused by that significant a reduction in charging efficiency.

This brings up an interesting point that we haven't paid much attention to. Most of the EVs we've done at my work seem to suffer from higher impedance more so than decreased range as they age. I'm sure the Leaf BMS tracks cell impedance (the Prius does).. We just haven't found it (or looked for it). I would think an easy enough test could be done with a simple voltage display on any of these Gid meter devices. At a moderate SOC (say 50-80%) note the pack voltage at a stop light when you're in front. Do a full throttle acceleration when the light turns green and note after 2-3 seconds what the pack voltage drops to (and if possible the current, although in that SOC range I would think most Leafs would pull about the same). Note the delta Voltage and from that we can calculate the pack impedance. hmm.. This might be a neat new feature for the LeafDD.

 

[Boomer23]

I re-parsed an old log from March 2012 where I was experimenting with the 79b messages (but not understanding the results at the time) and was able to extract my SOH and Ah from it at 87.7% and 59.1Ah. Lost my first bar two months later. Now, 15 months later, I am reading 63.4% and 46.0Ah. At that time, I was getting 254 gids on a 100% charge, pulling ~20.4kWh from the wall. Now I am pulling 18.8kWh from the wall to reach 196 gids on a 100% charge.

Ouch! :shock: That sucks.. In a somewhat morbid way I'll be interested to hear what kinds of battery temps you see this weekend during our SW heatwave..

Just to finish my little tale, True Gids this morning were 284 and 101%!!!!
Just goes to show that AH readings for a new car can be misleading.

Nice!!! Good to know that even in this heat the BMS can still giveth and not just taketh away!
101% what? How many Ahs is that? I'm guessing over 67.. It'd be interesting to see the health reading.

Greg, are you coming to the meetup Sat morning in SA? I'd love to get a health reading.

 

[foobert]

New "Leaf Battery App" user joining the party:

Build: 2011-10
In service: 2011-11-13
Miles: 17.8K

A bit disappointing since I own the car and have babied the battery as much as reasonably possible.

Question about what data to believe. Drove into work this AM, here's the stats:
Distance: 15.5 miles
M/kWh on the dash: 5.8
M/kWh calculated from LB app: 15.5/3.227 = 4.8 (app showed 3227 Wh consumed)

This is a huge discrepancy, and I wonder how common it is?

 

[GregH]

I re-parsed an old log from March 2012 where I was experimenting with the 79b messages (but not understanding the results at the time) and was able to extract my SOH and Ah from it at 87.7% and 59.1Ah. Lost my first bar two months later. Now, 15 months later, I am reading 63.4% and 46.0Ah. At that time, I was getting 254 gids on a 100% charge, pulling ~20.4kWh from the wall. Now I am pulling 18.8kWh from the wall to reach 196 gids on a 100% charge.

Ouch! :shock: That sucks.. In a somewhat morbid way I'll be interested to hear what kinds of battery temps you see this weekend during our SW heatwave..

Just to finish my little tale, True Gids this morning were 284 and 101%!!!!
Just goes to show that AH readings for a new car can be misleading.

Nice!!! Good to know that even in this heat the BMS can still giveth and not just taketh away!
101% what? How many Ahs is that? I'm guessing over 67.. It'd be interesting to see the health reading.

Greg, are you coming to the meetup Sat morning in SA? I'd love to get a health reading.

Normally I'd be able to catch the tail end of Gary's Hometown Buffet gang after my Saturday morning run but since I'll be running at the beach and given the heat I may have no choice but to jump in and go for a swim! Since you're in Irvine I could swing by on my way home though. I'll call/text you late morning.

 

[Boomer23]

Normally I'd be able to catch the tail end of Gary's Hometown Buffet gang after my Saturday morning run but since I'll be running at the beach and given the heat I may have no choice but to jump in and go for a swim! Since you're in Irvine I could swing by on my way home though. I'll call/text you late morning.

That'll work, thanks!

 

[mxp]

Hello,

Can someone help explain my numbers? Thanks!

2011 Leaf SL (July 1, 2011 pickup)
3 days a week 100% charge (overnight); other days 80%.
20k miles ODO

Warm morning today June 28, 2013. 6 temp bars showing even before drive.

Data below taken after 100% overnight charge, about 8am:
80def F
AHr=58.84 CAP=88.81%
91.5% SOC 242 gids

 

[DaveEV]

Can someone help explain my numbers? Thanks!

2011 Leaf SL (July 1, 2011 pickup)
3 days a week 100% charge (overnight); other days 80%.
20k miles ODO

Data below taken after 100% overnight charge, about 8am:
80def F
AHr=58.84 CAP=88.81%
91.5% SOC 242 gids

Looks pretty normal for a 2 year old LEAF in the warm side of the Bay Area...

 

[mksE55]

Here is my first full charge with the app. no setting changes. not quite 2 yrs old and 23,000 miles . lost 2 bars and lately think I am close to losing my 3rd bar as it seems I have lost more range. now getting about 46-50 mile range any thoughts or repeat test that could help garner more info.

94% SOC
15.7 kWh
196 GIDs 69.8%

Ahr 46.44 70.09%

first time plugging in
63.2% SOC
10.6 kWh
132 Gids 47%



Thanks

 

[KJD]

How do you do a screen capture on android ? Is that a built in function or something extra ?

 

[mksE55]

How do you do a screen capture on android ? Is that a built in function or something extra ?

usually the home button and the power button push at the same time. does take a few tries some times. but works. check youtube for your model if that doesnt work they all do it.