Due to an illness and then a hurricane, I let my car sit in an enclosed garage with what I thought was a full main batty and a disconnected aux battery for over a year. Replaced aux battery, car went to ready status ok, but fuel gauge showed no bars. Put car on charge, charger kicked out within a couple hours with fuel gauge showing only 2 bars. Hooked up charger again, kicked out after a few minutes now showing 3 bars. Drive car, got about 5 miles per bar, brought her home with zero bars but no tortoise. Range shows 1 mile. Put her in ready state, put headlamps on. After 4 hours I figure that should use another bar. (1kWh). After about 30 mins tortoise came on and then when I checked after an hour tortoise had disappeared. So had READY indicator. Lights still bright after 1.5 hours. Shut her down and then back in ready mode .. tortoise and READY came back but after a few mins both went off. Decided to start charging cycle and not sure where that will end up. Do I have a malfunctioning gauge, or a bad main battery? Car has only done 25k and it's a 2012.
Fuel gauge vs tortoise
- Thread starter vh2q
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Well after starting a charge cycle, the charger kicked out after a few minutes and now it will only stay in charge mode for a few seconds. Each time the charge starts normally .. The Orange and green are on, the cooling fan comes on, then after 30 secs or so the charger goes into ready mode. So I can't even get her to one bar.
Sorry to hear about your troubles.
From your symptoms it sounds like you might have a defective Onboard Charger OBC and a blown fuse in the MCU.
We have a big thread about all the folks with that failure, and lots of information about the OBC, fuse, etc.
Mits has extended the warranty to cover the OBC out to 10 years just like the pack.
When you bought a new aux to replace the old one, did you charge it first?
When you go to READY, does the 12V aux battery voltage go up to 14.4V?
There is a 30 Amp fuse under the cover of the Motor Control Unit MCU in the rear engine compartment that will usually fail when the OBC fails. This will cause the 12V aux to not get charged when the car is in READY. So when you ran your test it could be that the new aux got discharged. If so recharge the aux and the car should go to READY if the pack is not too low. With a good strong aux then you may be able to get the pack to charge, if the OBC is not failed. The DCQC Chademo would still work to charge even if the OBC has failed. Otherwise you might need a tow to a dealer for a new OBC and fuse.
From your symptoms it sounds like you might have a defective Onboard Charger OBC and a blown fuse in the MCU.
We have a big thread about all the folks with that failure, and lots of information about the OBC, fuse, etc.
Mits has extended the warranty to cover the OBC out to 10 years just like the pack.
When you bought a new aux to replace the old one, did you charge it first?
When you go to READY, does the 12V aux battery voltage go up to 14.4V?
There is a 30 Amp fuse under the cover of the Motor Control Unit MCU in the rear engine compartment that will usually fail when the OBC fails. This will cause the 12V aux to not get charged when the car is in READY. So when you ran your test it could be that the new aux got discharged. If so recharge the aux and the car should go to READY if the pack is not too low. With a good strong aux then you may be able to get the pack to charge, if the OBC is not failed. The DCQC Chademo would still work to charge even if the OBC has failed. Otherwise you might need a tow to a dealer for a new OBC and fuse.
Well the new aux was sitting for about a month before install but I figured it would charge with the main pack. And yes I probably ran it down some when I had the lights on. So I removed aux and have it on a charger now. When it's fully charged I will put it back in car and see what happens. Just hoping it's not a bad main battery. Your input was most enlightening!
Charged aux out of car, put it back, car is now taking a charge. But if dc-dc box is shot then aux will not be charged thru main while charging or driving right? And it will run down leaving me stranded even if main is still good?
Car purchased in FL is in Bahamas voiding Mits warranty according to fine print. So I will need to swap out box myself. How hard is that?
Car purchased in FL is in Bahamas voiding Mits warranty according to fine print. So I will need to swap out box myself. How hard is that?
Sounds like good news!
You will need to measure the voltage on the aux while in READY to determine if the MCU fuse has blown, but if your pack is charging then that means the OBC is okay, and i would guess that the fuse is likely okay also or the car wouldn't charge.
i use a little plug-in USB phone charger that has a digital voltmeter display--just plug it in the cigar lighter socket and reads the aux voltage.
It appears you just had a weak aux that couldn't supply the necessary power to enable charging the pack.
You will need to measure the voltage on the aux while in READY to determine if the MCU fuse has blown, but if your pack is charging then that means the OBC is okay, and i would guess that the fuse is likely okay also or the car wouldn't charge.
i use a little plug-in USB phone charger that has a digital voltmeter display--just plug it in the cigar lighter socket and reads the aux voltage.
It appears you just had a weak aux that couldn't supply the necessary power to enable charging the pack.
Back to square one .. Car was still charging when I went to bed (about 2 hours in) but gauge showed zero bars with flashing pump. Got up this am charger had kicked out but only 3 bars showing. Hooked up my RC LIPO charger to aux and it read 14.2V. Checked charger again it had clicked on while I was hooking up LIPO charger. After 20 mins charging a tiny RC battery, aux went to 13.1, charger had kicked off again. Removed charging handle, turned ignition to ready, aux voltage went back to 14.2V.
So I conclude no problem with OBC or DC converter. Either gauge is way out of whack, or main won't take more than 3 bars. How do I tell?
So I conclude no problem with OBC or DC converter. Either gauge is way out of whack, or main won't take more than 3 bars. How do I tell?
PV1
Well-known member
At this point, I would invest in an OBDLink LX bluetooth and the Android app Canion. This will allow you to see what the cell voltages are within the pack. The pack may simply be way out of balance.
It does appear that the OBC and DCDC are working okay, possibly the 12V aux is weak or needs a good long charge at 14.4 to desulfate the plates. Take it out and charge it up on the bench so acid doesn't overflow in the car.
With the car being out of service for so long, it may be that the EV-ECU has gotten confused or lost some memory values about the capacity of the pack. It keeps track of all the current flow in and out of the main pack while charging or driving, and it has a baseline value for how much capacity the pack contains. So it will cut off charging if it thinks the capacity has been reached. When you put the aux back it in might reset any error codes and wake up.
The other possibility is that one or more cells is weak and holding down the rest of the pack from being charged fully.
If you could get a ScanTool LX obdii dongle and the android canion app, you would be able to view the individual cell voltages to determine what is the status of the pack.
Otherwise you could drive down to 2 bars and then charge the car, and do this several times to see if the systems will wake up and come back to life.
i have posted in another thread about pulling the MCU cover to read the pack voltage with a voltmeter when you turn the key to READY mode. It is a dangerous high voltage task that requires much care and attention to detail, but that could provide another clue about the pack.
With the car being out of service for so long, it may be that the EV-ECU has gotten confused or lost some memory values about the capacity of the pack. It keeps track of all the current flow in and out of the main pack while charging or driving, and it has a baseline value for how much capacity the pack contains. So it will cut off charging if it thinks the capacity has been reached. When you put the aux back it in might reset any error codes and wake up.
The other possibility is that one or more cells is weak and holding down the rest of the pack from being charged fully.
If you could get a ScanTool LX obdii dongle and the android canion app, you would be able to view the individual cell voltages to determine what is the status of the pack.
Otherwise you could drive down to 2 bars and then charge the car, and do this several times to see if the systems will wake up and come back to life.
i have posted in another thread about pulling the MCU cover to read the pack voltage with a voltmeter when you turn the key to READY mode. It is a dangerous high voltage task that requires much care and attention to detail, but that could provide another clue about the pack.
I charged the aux on the bench last night using my house inverter set for lead acid open cell, 20A charge rate in stage 1 til it got up to voltage, then held at 14.4 V with controlled amps for an hour, then float for about 15 mins. It was reading 13.1V this morning after being plugged in all night, where is was held at 14.2V at least a few hours. It's a new battery so I think it's fine. It could be the charger or the electronics that control when the charger lets go.
Would like to know whether the tortoise mode is triggered by main batty voltage, or by the software logic that keeps track of amp hours in and out. I got the tortoise icon after I drove it to zero bars yesterday. I am hoping the data in the memory is messed up and not a main batty fail.
Would like to know whether the tortoise mode is triggered by main batty voltage, or by the software logic that keeps track of amp hours in and out. I got the tortoise icon after I drove it to zero bars yesterday. I am hoping the data in the memory is messed up and not a main batty fail.
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?
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?
PV1
Well-known member
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.
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.
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.
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.
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
Well-known member
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.
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.
DBMandrake
Well-known member
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.vh2q said:
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:
http://myimiev.com/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)
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
Well-known member
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)vh2q said:
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.
+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.
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.
