Question about a fault and the aux battery

One of the four iMiev’s we have has developed an intermittent fault.

It’s a 2012/3 Australian delivered model that is used only 8 months a year. On four occasions over the past year the Amber Exclamation Mark warning light comes on the dash (the one through the little amber car symbol) and this is followed by the turtle when you try to drive the vehicle. The fault occurs with the traction battery fully charged (or close) and in a wide variety of temperature. Until the last occurrence, the fault could be corrected by restarting the car. It did appear moving the gear selectors up and down a few time helped but this might be our imagination.

Anyway the fault could not be cleared the other day and the only way I could clear the condition was to disconnect the Aux Battery. As the vehicle was made in 2012 and sat for a couple of years before we purchased it new, I was happy to replace the battery. BTW, the battery is now connected to a solar trickle charger when stored for 4 months each year and the traction pack left at 80%.

The dealers are absolutely useless in our part of Australia but we have had no other issues other than tire replacement. I have a long background in DIY Ev’s so happy to deal with longer term issues. I also use caniOn to monitor the life of the pack but as a diagnostic tool for the other issues it is not much help.

So three questions….

1 - Has anyone else experienced a similar issue?
2 – Does anyone know of a scan tool (my standard OBDII scanners don’t work on the I’s) that could helpful for these issues?
3 – Is there a “Hard Reset” of some sort somewhere I haven’t found? Doesn’t seem to shown in the service manual?? Maybe the Mitsi Factory Scan tool clears and resets issues but can’t find that out!

Any tips appreciated.

Also, no faults have occurred after the Aux Battery replacement.

Cheers
Bruce

Update: Just bench testing the old original 34B19L battery and at this stage of testing it does appear to not be holding a charge very well…..

The 12 volt aux. battery was known to cause a wide array of issues on the old RAV4-EVs. It sounds like something similar happened here.

The other thing that I'm thinking (given another thread with a similar issue) is that the MCU (drive inverter) needs replaced. There was a recall here in the US that affected a good portion of the fleet.

Best I can say is to keep running with the new battery and see how it behaves. As for your questions:

1. There is another thread where after quick charging and returning to highway driving caused RBS, Turtle, and MCU warning lights (amber car with !) to come on. This resulted in regen being disabled and power output being limited. It may have been caused by an overheated cell in the battery pack, but is still under investigation.
2. An OBDLink MX or LX may be able to read and reset trouble codes, but it requires the proper application for a phone or computer (closest thing right now is EVBatMon, which is believed to query the ECU for Calculated Amphour Capacity, or CAC as known in the Tesla world).
3. So far, the only way to clear codes is to either go to a dealer that has a MUT-3 tool, or procure one yourself. There is also a PC-side program required besides the box itself.

Cometboy

When I went through the battery replacement adventure two years ago, I had the MCU warning light come on (amber car with I). It makes sense that you would get this error if one of the cells is out of voltage range of (2.75v to 4.1 v). If you noticed that this happened mostly when the car was fully charged, it suggests a high voltage on one of the cells which you should be able to see through Canion. It does not suggest you actually have a high voltage on one of the cells but rather you are measuring a high voltage.

Also, if you are able to drain the battery a little (not sure if heater still works with MCU warning light on), I would guess the alarm will clear.


Dave

cometboy, all good questions; unfortunately, no good answers for you -

The Mitsubishi MUT3 with PC and i-MiEV-specific software is currently the only known gadget that can access the i-MiEV and perform diagnostics and resets. No one on this forum (that I know of) has yet obtained one. CaniOn is a passive data reader and the recently-released EvBatMon is presently limited but does perform a very useful interrogation for battery capacity.

Two additional comments if I may -

For long-term storage, leaving the primary traction pack at a lower SoC (25%-45%) is currently considered preferable. Your storage at 80% was perhaps a bit too high long-term, especially if high ambient temperatures were involved.

Using a solar panel to float charge the 12v battery is a great idea (I do it); HOWEVER, there is a caveat: the solar panel, no matter how small it is, should feed a 12v regulator in order to limit the maximum voltage seen by the 12v battery (typically 13.2v, but a bit higher is ok for the flooded lead-acid battery). Connecting even a very small solar panel directly to the 12v battery will murder it long term. The key word here is 'smart' float (even multi-stage) charging rather than unregulated trickle charging.

cometboy, if you do find out more information about resetting i-MiEV trouble codes a posting here would be appreciated as more and more of us will start becoming hands-on involved with our i-MiEVs as the warranties expire.

Thanks for the replies…

PV1, can you point me to the link or any other comments on “The other thing that I'm thinking (given another thread with a similar issue) is that the MCU (drive inverter) needs replaced. There was a recall here in the US that affected a good portion of the fleet.” I can seem to find a reference? Was there a recall reference number given back them??

I will check out “EVBatMon” but as you say I don’t think that will help with problems such as this.

This vehicle is/was new old stock and as mentioned used only maybe 6 months in the year. For those that don’t know, Mitsubishi Australia stop i-Miev sales here a couple of years ago and dumped all stock below cost price. This was one of them and basically sat for a couple of years prior to my wife buying it. A few enthusiasts in the electric car clubs here snapped them up fairly quickly. Our group of friends/family purchased 3 more and results have been great. The other ones average 25,000 to 30,000 km a year. I have measured very little drop in the range over the last couple of years. The packs all stay balanced and very health – nice little packages for urban use.

I would love to get a MUT-3 tool (or similar) for future use. As they age the unavoidable will happen and some form of diagnostic tool will be needed….

dniemeyer99, I have attached some caniOn screenshots grabbed at the time. Certainly the pack has always looked perfect according to caniOn. I ruled out anything pack related but open to any ideas! Thanks.



Pack image - before switching to "Ready" position



Pack image - "Ready" position



Pack image - Temperature (winter here in South Australia)

JoeS, yes I use a good voltage regulator from the solar panel to the battery – currently 22ma into the battery and the battery is at 12.8 volts. I use the same on my other vehicles when being stored and have had on issues to date.

JoeS, you bring up an interesting point about what SOC is best when storing cells with this chemistry. My assumption has always been that the 80% figure was the magic number. I currently store my numerous unused LiPo’s at this SOC as well and my fancy LiPo charger takes the cells to 80% when using the “Storage” feature of the charger. Maybe we should start a new thread on this topic if you have better information to support a much lower SOC figure? Others may also have an old misinformed view like I do!

edit- new thread under "Batteries and Battery Management" started here: http://myimiev.com/forum/viewtopic.php?f=23&t=3094

Thanks again for he comments….

Bruce