ed5000
Posts: 122
Joined: Mon Jul 27, 2015 9:22 pm
Location: Castro Valley, CA

My Car is Only Charging Up to 12 Bars

Wed Mar 15, 2017 5:58 pm

Hello Everyone. For the last three days my car only charges up to 3/4 of a "tank", i.e. it only charges up to 12 bars. From what I've read here it could be a cell going bad in the traction battery so I checked my Canion ap and found cell #75 low at 3.880 volts while all the rest are at 4.010 volts.

I have an appointment at the local Mitsu dealer for next Monday but in the meantime, I've been taking it easy and driving the car in only "eco" mode on my 32 mile round trip commute to work. When I get home I have only 12 miles/3 bars remaining each day. If need be I can charge at work but I'm wondering if I should park the car until the Monday appointment.
2012 ES, Cool Metalic Silver, no quick charge, no fog lights and no navi but a cold weather package for when it gets 13 below, wait - it never gets that cold here.
"Silver Shadow"

zzcoopej
Posts: 61
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Location: Gosford, Australia
Contact: Website

Re: My Car is Only Charging Up to 12 Bars

Wed Mar 15, 2017 6:41 pm

ed5000 wrote: I'm wondering if I should park the car until the Monday appointment.

I'm no expert however I've done a lot of reading on battery degradation & cell failure and have a keen interest in understanding it further.
I don't think continuing to drive before the dealer sees it will further damage the battery as the dealer doesn't have any way of reversing the damage to the faulty cell (if that is infact your issue). All the deailer can really do is a full cycle with balancing after resetting the BMU as you would when a battery or faulty cell is replaced.
I now know of 2 owners who have successfully replaced faulty cells so it doesn't sound like the damage spreads by stressing out other cells, as the BMU limits the cycling to the level of the most damaged cell (although "only charging to 12bars" is new to me). I thought from the others who have had damaged cells that the battery still charges to 16 bars and just the RR and range actually achieved diminishes.
How recently have you driven to <2 bars and then done a full charge, and after that left the car on for a while after 16 bars was reached (which triggers cell balancing)? It is also possible if you are using an off-peak dedicated circuit that is on for only 6 or 8 hours that the final balancing stage is not getting a chance to run to completion.

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PV1
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Re: My Car is Only Charging Up to 12 Bars

Wed Mar 15, 2017 7:19 pm

Failing to charge to 16 bars has always been the telltale sign of a faulty cell. Capacity degradation, on the other hand, will only show by a decrease in RR but will still charge to 16 bars. The more the faulty cell discharges, the less and less the battery will charge. You are correct that the car will adjust the pack's SoC based on the faulty cell's voltage, so no cell will be driven outside of its specified voltage range. However much charge the pack can take before a cell reaches 4.11 volts is all the more charge the car will put into the pack.

I would continue to drive the car as long as possible, as even when it sits, the bad cell continues to discharge, which has left at least one member with a bricked car. Eventually, if the cell continues to lose charge, you'll get to a point where the MCU warning light will start coming on. But, if your appointment is Monday, you should be able to continue using the car for the rest of this week (but Friday's commute will be pretty close ;) ). Keep your cord with you.

Using CaniOn, it might be a good idea to track the charged %SoC. My hunch is that the percentage of a "full" charge will continue to decrease (my car got to the point where I only had about 10-15 miles of charge available), however one member managed to bring their pack back into balance with repeated driving and charging.
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kiev
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Re: My Car is Only Charging Up to 12 Bars

Wed Mar 15, 2017 7:43 pm

A failing cell is an Unknown Quantity--there is no predictable response or future life estimates available.

How much hassle would you suffer if the cell runs out on the way to work or on the way home?

It seems that you were lucky that it failed gracefully and didn't (yet) leave you stranded, and maybe not press your luck too far--unless you feel really lucky, then go for it and share the adventure...
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ed5000
Posts: 122
Joined: Mon Jul 27, 2015 9:22 pm
Location: Castro Valley, CA

Re: My Car is Only Charging Up to 12 Bars

Wed Mar 15, 2017 8:29 pm

zzcoopej wrote:How recently have you driven to <2 bars and then done a full charge, and after that left the car on for a while after 16 bars was reached (which triggers cell balancing)? It is also possible if you are using an off-peak dedicated circuit that is on for only 6 or 8 hours that the final balancing stage is not getting a chance to run to completion.


That is a good point. I have been using the car's delay timer which is set for 5 hours of charging. That seems fine for charging up a half full battery but it may need more time now. I went ahead and plugged it in without the delay.

PV1 wrote:Failing to charge to 16 bars has always been the telltale sign of a faulty cell. Capacity degradation, on the other hand, will only show by a decrease in RR but will still charge to 16 bars. The more the faulty cell discharges, the less and less the battery will charge. You are correct that the car will adjust the pack's SoC based on the faulty cell's voltage, so no cell will be driven outside of its specified voltage range. However much charge the pack can take before a cell reaches 4.11 volts is all the more charge the car will put into the pack.

I would continue to drive the car as long as possible, as even when it sits, the bad cell continues to discharge, which has left at least one member with a bricked car. Eventually, if the cell continues to lose charge, you'll get to a point where the MCU warning light will start coming on. But, if your appointment is Monday, you should be able to continue using the car for the rest of this week (but Friday's commute will be pretty close ;) ). Keep your cord with you.

Using CaniOn, it might be a good idea to track the charged %SoC. My hunch is that the percentage of a "full" charge will continue to decrease (my car got to the point where I only had about 10-15 miles of charge available), however one member managed to bring their pack back into balance with repeated driving and charging.


Thanks, PV1. Maybe I can exercise the bad cell back to life? I'll bring the cord for sure. 8-)

kiev wrote:How much hassle would you suffer if the cell runs out on the way to work or on the way home?

It seems that you were lucky that it failed gracefully and didn't (yet) leave you stranded, and maybe not press your luck too far--unless you feel really lucky, then go for it and share the adventure...


The hassle factor wouldn't be too bad. I commute on a busy freeway but, right now I'm only in the slow lane and there's a breakdown lane all the way to work. I just need to have a cord and a cell phone with me. I'll let you know if any of this changes. :)
2012 ES, Cool Metalic Silver, no quick charge, no fog lights and no navi but a cold weather package for when it gets 13 below, wait - it never gets that cold here.
"Silver Shadow"

zzcoopej
Posts: 61
Joined: Wed Jul 08, 2015 7:23 pm
Location: Gosford, Australia
Contact: Website

Re: My Car is Only Charging Up to 12 Bars

Wed Mar 15, 2017 8:54 pm

ed5000 wrote:That is a good point. I have been using the car's delay timer which is set for 5 hours of charging. That seems fine for charging up a half full battery but it may need more time now.


Remember it is only after you drop to <2bars (ie flashing) that the BMU will trigger cell balancing when the battery is subsequently fully charged. If what you say has been going on for many months, cell balancing may not have happened to your battery in a LONG time and could easily explain a cell drifting well out of balance.
The letter from "Mitsubishi Motors North America, Inc" which describes this procedure also mentions to ensure ambient temps between 50 and 122 degrees Fahrenheit, and only using a level 1 or 2 charger (ie not fast charge). They recommend the procedure is done once in the first year and every 2 years after that, however I would think it would depend significantly on your driving and charging patterns.

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ed5000
Posts: 122
Joined: Mon Jul 27, 2015 9:22 pm
Location: Castro Valley, CA

Re: My Car is Only Charging Up to 12 Bars

Wed Mar 15, 2017 9:03 pm

zzcoopej wrote:Remember it is only after you drop to <2bars (ie flashing) that the BMU will trigger cell balancing when the battery is subsequently fully charged. If what you say has been going on for many months, cell balancing may not have happened to your battery in a LONG time and could easily explain a cell drifting well out of balance.


Wow, good to know. My car actually did go to 2 bars flashing today for the first time in some time. The freeway jambed up 5 miles from home today and I took a detour. The car just barely went to the 2 bars when I got home.
2012 ES, Cool Metalic Silver, no quick charge, no fog lights and no navi but a cold weather package for when it gets 13 below, wait - it never gets that cold here.
"Silver Shadow"

zzcoopej
Posts: 61
Joined: Wed Jul 08, 2015 7:23 pm
Location: Gosford, Australia
Contact: Website

Re: My Car is Only Charging Up to 12 Bars

Wed Mar 15, 2017 9:17 pm

ed5000 wrote: My car actually did go to 2 bars flashing today for the first time in some time.


How long would you say (in Time and Km) since you did a full charge from <2 bars, including enough time to balance considering I doubt 5 hours is enough)? Are we talking months or years, and 10,000km or more?

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ed5000
Posts: 122
Joined: Mon Jul 27, 2015 9:22 pm
Location: Castro Valley, CA

Re: My Car is Only Charging Up to 12 Bars

Wed Mar 15, 2017 9:40 pm

zzcoopej wrote:
How long would you say (in Time and Km) since you did a full charge from <2 bars, including enough time to balance considering I doubt 5 hours is enough)? Are we talking months or years, and 10,000km or more?


The last week of January I took a road trip and got it down to one bar.
2012 ES, Cool Metalic Silver, no quick charge, no fog lights and no navi but a cold weather package for when it gets 13 below, wait - it never gets that cold here.
"Silver Shadow"

zzcoopej
Posts: 61
Joined: Wed Jul 08, 2015 7:23 pm
Location: Gosford, Australia
Contact: Website

Re: My Car is Only Charging Up to 12 Bars

Wed Mar 15, 2017 9:46 pm

ed5000 wrote:The last week of January I took a road trip and got it down to one bar.


That's pretty recent. Did it get more than 5 hours of charging before you drove it again?

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