kiev
Posts: 1070
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Fuel gauge vs tortoise

Sun Jan 05, 2020 12:38 pm

Sounds like you are taking good action to rule out the aux battery.

From what i've read, the turtle mode could be triggered by either

any one cell dropping below the low voltage limit,
or
the pack voltage dropping below a certain low voltage limit,
or
the calculated capacity value approaching or exceeding a system limit.

A incorrect stored or calculated value could be giving erroneous data and throwing the system off.

If you have no error lights on the dash then that is a good thing.

Since the car has set in a somewhat salty and humid climate, there could be moisture-induced corrosion of contacts and terminals. You could try demating and inspecting the low-voltage connections from the pack and at the BMS and EV-ECU under the rear seat.

If you drive the car from 3 bars down to turtle mode, how many miles do you travel? How many miles does the RR gauge indicate at 3 bars?
kiev = kenny's innovative electric vehicle

PV1
Site Moderator
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Location: Pittsburgh, PA

Re: Fuel gauge vs tortoise

Sun Jan 05, 2020 1:06 pm

Also worth noting is normal behavior of the charge gauge. Around 12.5% charge, the bottom bar (1st bar) disappears. Around 10.5%, the turtle (tortoise) light illuminates, and the car will disable cabin heat and A/C and allow only the fan to run (if the cabin air system is active). So, there is normally a gap between having a bar of charge and the turtle light illuminating, and this usually happens with 1-2 miles on the RR gauge (below 1 mile of range, the gauge simply shows - - - ). From what it sounds like, this is all normal.

I second KiEV in that the car sitting so long without 12 volt power likely resulted in the ECU losing capacity information. Good news is that the car can re-learn the battery and eventually restore full charge capacity.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015
"Photon" - 2017 Bolt EV LT in Orange with QC - 7/31/2017

Solar-powered since 10/10/2013

vh2q
Posts: 30
Joined: Fri Dec 18, 2015 12:39 pm

Re: Fuel gauge vs tortoise

Sun Jan 05, 2020 5:45 pm

Yesterday, starting out at 3 bars (actually 2 and a partial which is all the juice it would take) I drove 10 miles and the bars went to zero with one mile of range showing but no tortoise. Today, again starting with 3 bars showing, I did the same 10 miles returning with about a half bar and range of 4 miles remaining. The third bar seemed to last a little longer on this trip than on the prior trip.

Charging kicked off tonight, with 3 bars showing, range indicates 14 miles which would indicate the third bar is almost full.

It looks like I am getting a small improvement with each charge.

Do I need to remove the metal cover under the rear seat to clean connections? What other covers do I need to remove to clean connections? Any particularly important connections? I already checked the instrument fuse tabs and they were bright.

vh2q
Posts: 30
Joined: Fri Dec 18, 2015 12:39 pm

Re: Fuel gauge vs tortoise

Mon Jan 06, 2020 10:18 am

Another small improvement today. But I have a theory: when I put car in storage and disconnected aux, ECU memory saved status as 2.5 bars of charge needed. This is about consistent with my recall. Meanwhile, main self discharges to almost zero over the year plus it was sitting. So now when I wake it up, ECU still thinks it only needs 2.5 bars of charge. Then I run it back to zero and ECU puts 3 bars (a little more than was used) back. And so on. But at this rate it will take forever to get back to a full charge cycle. Any ideas?

DBMandrake
Posts: 264
Joined: Mon Mar 20, 2017 4:57 am
Location: Scotland

Re: Fuel gauge vs tortoise

Wed Jan 08, 2020 4:50 am

Do you have an Android phone or tablet capable of running Canion ?

If so, do yourself a favour and get an OBDLink LX so you can use Canion - this will give a wealth of information about the state of the traction battery, including the BMU reported Ah capacity, individual cell voltage and pack voltage, reported SoC, charge and discharge current etc... and would go a long way towards diagnosing your issue. Otherwise it's all just a lot of guesswork.

If the 12v battery was disconnected for a long time the BMU may have defaulted back to the factory original 45.8Ah. If your battery is significantly degraded this will cause issues as the cells will hit their low voltage limit before the BMU expects the battery to be down to 10% SoC, this can cause it to kick into turtle mode unexpectedly.
- Simon

EV: 2011 Peugeot Ion
ICE: 1997 Citroen Xantia V6

vh2q
Posts: 30
Joined: Fri Dec 18, 2015 12:39 pm

Re: Fuel gauge vs tortoise

Wed Jan 08, 2020 1:21 pm

I do have an Android phone. Where do I get the other gizmo? I bought a code scanner a few years ago but it never produced anything intelligible.

Car charged up to 15 miles/3 bars again today, no real gain vs. Yesterday.

DBMandrake
Posts: 264
Joined: Mon Mar 20, 2017 4:57 am
Location: Scotland

Re: Fuel gauge vs tortoise

Thu Jan 09, 2020 8:14 am

vh2q wrote:I do have an Android phone. Where do I get the other gizmo? I bought a code scanner a few years ago but it never produced anything intelligible.

Car charged up to 15 miles/3 bars again today, no real gain vs. Yesterday.

If you already have an Android phone download "Canion" from the play store and have a look at it, it will give you an idea of what it can do.

This is the OBDLink LX:

https://www.obdlink.com/lxbt/

Although I'm in the UK I bought mine from scantool in the US (via their Amazon link) as it was much cheaper than buying from Amazon UK... go figure...

Most generic OBD-II scanner software cannot read an EV - in fact the software bundled with the OBDLink adaptor cannot either, however software written specifically for certain models of EV's can use the adaptor, such as Canion which is written for the i-Miev/Ion/C-Zero.

Another Android app worth checking out that is compatible with your car is "Hobdrive" - there is a free version with some features and a full version which is not very expensive.

It provides much of the same information as Canion but does provide additional information from the car which Canion does not which could be potentially useful for diagnosis and it does also have limited fault code resetting ability. The author of Hobdrive even posts right here on this forum:

viewtopic.php?f=9&t=4101&hilit=hobdrive

(The Canion authors have also posted on this forum however don't seem to be active recently)
- Simon

EV: 2011 Peugeot Ion
ICE: 1997 Citroen Xantia V6

vh2q
Posts: 30
Joined: Fri Dec 18, 2015 12:39 pm

Re: Fuel gauge vs tortoise

Sat Feb 22, 2020 11:18 am

Well fast fforward a month, I got set up with hobdrive and took a look at the ECU data. Getting two error codes P1A4B (cell voltage abnormal) and P1A2F (cell error). Charged car up to 3 bars, which is all it will take, and read. voltages. All around 4.1V except one cell is 3.79V. TrIed to actuate smoothing from hodrive but not clear to me. it did anything. What am I missing here? Is there something else I should look at or reset using hodrive? I still don't know whether the problem is the gauge (ie showing 3 bars when it's actually fully charged) or the charge cycle cutting out too soon, I have run it down to the tortoise symbol a couple of times thinking that may reset the BMU but it doesn't seem to make much difference. Car was fine until I let it sit without the accessory battery for about a year.

DBMandrake
Posts: 264
Joined: Mon Mar 20, 2017 4:57 am
Location: Scotland

Re: Fuel gauge vs tortoise

Sat Feb 22, 2020 11:32 am

vh2q wrote:Well fast fforward a month, I got set up with hobdrive and took a look at the ECU data. Getting two error codes P1A4B (cell voltage abnormal) and P1A2F (cell error). Charged car up to 3 bars, which is all it will take, and read. voltages. All around 4.1V except one cell is 3.79V. TrIed to actuate smoothing from hodrive but not clear to me. it did anything. What am I missing here? Is there something else I should look at or reset using hodrive? I still don't know whether the problem is the gauge (ie showing 3 bars when it's actually fully charged) or the charge cycle cutting out too soon, I have run it down to the tortoise symbol a couple of times thinking that may reset the BMU but it doesn't seem to make much difference. Car was fine until I let it sit without the accessory battery for about a year.

The cell smoothing option in Hobdrive is supposed to activate the cell balancers manually in the battery pack however I did not have any luck getting this to work when I did a cell swap and had an imbalance to correct. (To be fair my dealer diagnostic tool was also unable to do this)

Keep this in mind though - the cell balance resistors only draw 100mA, this is a tiny bleed current, so it will take a long time (dozens to hundreds of hours) to make any real dent on this level of imbalance.

When I did a cell swap I ended up with a 50mV imbalance at full charge so the cells I replaced were only reaching 4.05 volts when the others were at 4.1 volts. That small 50mV error took approximately 40 charge/discharge cycles over about 6 weeks of daily driving and use to equalise, however the car still worked normally during this period.

However your imbalance is 290mV - this is massive, and if we assume for the moment the cell is OK but it is only a SoC imbalance it would take approximately 240 charge/discharge cycles for the cell balancers to correct.

I think it's very unlikely that it is just a SoC imbalance, and that you almost certainly have a faulty cell, although a faulty LTC chip on the CMU board is a possibility.

Either way the pack will need removing from the car and the module containing the cell carefully removed so the cell voltage can be measured - if the voltage is indeed 3.79 volts the cell is faulty, if the voltage measures the same as the others the LTC chip on the CMU board for the module is faulty.

If you do perform a cell swap then to avoid the same mistake I made I would recommend you fully charge the pack in the car until all the other cells reach 4.1 volts, and make sure the replacement cell is fully charged to 4.1 volts before fitting it.

If you go ahead with a cell swap good luck and be careful as there is a risk of electrocution if you are not very careful and competant, and feel free to ask questions here. I took quite a few pictures of my cell swap job even though I never got around to posting them here.
- Simon

EV: 2011 Peugeot Ion
ICE: 1997 Citroen Xantia V6

kiev
Posts: 1070
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Fuel gauge vs tortoise

Sat Feb 22, 2020 11:57 am

+1 on Simon.

i would say from the cell data that you definitely have a bad cell. It only charges to 3 bars because that bad cell is pulling down the average. i had the same situation and could not get it to come up--the cell is defective and no good anymore. In the US this would be enough evidence to qualify for a replacement pack under warranty. Elsewhere would require either a cell swap or pack swap if one could be found.
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