EV system service required, among other things

[Project]

Hi all,

Bit of a saga coming up. Bought the PHEV two weeks ago from a branch in Milton Keynes, UK. 2 years old, 10,000 on the clock. I thought what could go wrong. Had two weeks of joy with it, really is a spaceship to drive compared to the old Alhambra. Got the charge point installed already on the house, so all good to go. Run it for about 300 miles so far in "EV" mode, only ran short on battery twice, so the ICE has done about 10 miles for us in all.

Wife went to fire it up last night and we got a whole myriad of issues come up on the dash, listed below.
EV system service required stop safely
Brake system service required
ASC system service required
BSW service required

The start/Stop button wouldn't turn off the car, it screamed if I left with the key, the drivers window wound down but wouldn't go up. The front passenger window worked and the rear driver side, the rear left wouldn't work. the boot would open but not shut and it wouldn't lock.

Called the dealership, they put me on to their service department, the technician there asked if I could call my insurance company to get the car towed to them. Not mega impressed with that TBH.

Had MAP cover (cant remember the acronym but its Mitsubishi breakdown cover for new owners), called them at 3:30Pm and they said they'd get the AA out to have a look and see if they could fix it, if not they'd get it towed back to the garage and give me a courtesy car (whole other thing, they'd give me the hire car if I paid for the insurance, at £10 a day!).

Thought the issue must be electrical, no way all that stuff just went wrong sat idle on the drive. Checked the AUX 12V battery in the boot, it's reading 8v, not good.

Called the garage's service lot again, explained it to them, and they said "well it's a dead battery". I asked if it could be an issue with the DC-DC converter, or if the car even had one to charge the 12v lead acid battery from the lithium system. he said
"nope, the car always starts the ICE for a few mins every time you run it".
So I called BS as I know what it sounds like when it runs the ICE and we hadn't been using it, fuel range hasn't gone down since we got it, save for the two times we ran out of EV range.

I'll summarize a little here, the AA never show, the hire car never shows, the recovery lot call me and say they wont get to me then the garage before they shut, so they'll come in the morning. So I'm left with the cruel irony of having to jump start my electric car with my work van so I can lock it.

Car gets recovered, recovery guy mentions he checked the battery under the bonnet (didn't know it had two 12v lead batteries) and that's reading 8v too. Dealer who sold it to us speaks to the wife in the morning and says he'll call back in an hour with an update. Nothing. I then call back at 3 Pm and he says the same. I then call back at 4:50 Pm (10 mins before they shut) and he says "I'm not sure if it's come in yet". So he puts me on to the service team. They confidently start the following dialogue:
Them - "It's here and we've had a look, the battery needs replacing"
Me - "Ok, which one"
Them - "what do you mean"
Me - "There's three batteries, which one needs replacing?"
-background mumbling-
Them - "The 12 volt one sir"
Me - "Great...WHICH ONE?!"
-more background mumbling-
Them - "The one in the boot"
Me - "Ok, so whats wrong with the one in the front? That was reading a low voltage too"
Them - "Just the one in the back sir, should be ready Friday"
-conversation quickly tails off as it's clearly approaching quitting time-

So I guess my questions to the hive mind on here;

Is it a two year old 12v lead acid battery? which are legendarily reliable.

Is it possible the front one is fine despite a similar low voltage?

Does the ICE always, or even occasionally run on first startup (which I've never heard) or is there a problem with mine there? Bearing in mind our standard startup procedure is hit the start button, hit the "EV" mode button, stick it in drive and go (without driving like a hooligan, I know if you boot it, even in "EV" mode, the ICE will start for extra punch).

Could it be an issue with a DC-DC converter that is supposed to charge the 12V batteries when plugged into the wall, which may explain why both front and rear 12v batteries are reading low voltages? Or have I made that system up in my head and they can only be charged via the ICE which I will have to use periodically to charge the 12v batteries?

Thanks for taking the time to read through! Little concerned the dealerships in house mechanics are talking out of their ass, trying to get a sense check and some more info on the car. Bit frustrated with the whole experience really.

CJ

 

[JohanvdH]

I do not think you have a second 12V battery under the bonnet.
The 12V battery in the boot is the only one.

I think the tech guy was not looking correctly as you can measure the battery voltage both directly from the battery in the boot and but choosing the correct wires (probably at the fusebox) under the bonnet.

Replacing the 12V battery in the boot should fix the problem you were experiencing.
It should be done under warranty as you just bought the car.

 

[Project]

Hi JohanvdH,

Thanks for the quick reply! I did think it odd that there would be two lead batteries in the car. I haven't looked under the bonnet (on modern cars whats the point, it's all aesthetic covers).

The recovery chap said he'd checked it there, I guess he was on about the terminals you mentioned. Crossed fingers it is just the battery. Read down through the older forum posts to pick up some knowledge, seen that I should be able to read about 14.4v when plugged in/turned on, when it's back I'll check that it is attempting to check the battery.

They have said it'll be done under warranty.

CJ

 

[jaapv]

As the 12V battery has no ICE starter motor to feed, it is quite small. It is easy to drain it, for instance, by leaving the lights on for a relatively short while. There is a good chance that there is nothing wrong with the battery but in any case you are lucky that they'll replace it on guaranty; the Mitsubishi one is exorbitantly expensive. The 12V battery is charged from the main battery periodically and when the car is switched on. As it leads an easy life it should last many years.

 

[Shadowelite]

What does the small 12v battery run tho?
Is it a good idea to keep a spare handy ? Maybe buy a gel battery ?
You would think since it has a massive 13.8kw battery (orwhat ever it is) That the car wont need a normal 12v battery
I think this might affect me As im buying a phev (once i fine one i like lol) And i work from my car, so i be in my car anywhere between 9h - 38h straight, having maybe interior light on (Work nights) to having door left open and windows ect
Sorry to high jack thread

 

[Regulo]

The drive battery is 300 Volts. The 12 Volt battery drives everything that a normal car has that's 12 Volts. It's small, as it only has to power up the electronics, not drive a starter motor. Some owners carry a small Lithium boost battery, just in case!

 

[greendwarf]

The drive battery is 300 Volts. The 12 Volt battery drives everything that a normal car has that's 12 Volts. It's small, as it only has to power up the electronics, not drive a starter motor. Some owners carry a small Lithium boost battery, just in case!

Whilst all this is true, its primary purpose is to fire up the operating system for the car - so if it is flat, you're stuck. Once the car is put into ready mode the main battery takes over and will maintain the 12volt just like a normal ICE car with the engine running.

However, just as in an ICE car, you wouldn't expect to be able to sit with the ignition on but without starting the ICE, a number of members of this forum have managed to run the 12v flat leaving the car switched on but not in ready mode and with heating, lights, radio etc. running!

 

[Shadowelite]

I would not leave the car switched on , i can easily turn it on just to open window ect just like a normal car
But some cars actually use power if you leave a door open for instance even if u turn the interior light off and ignition off
Hope this aint the case with the phev
Also is there anyway to see the charge of the 12v battery? I bought a obd or what ever its called and i will use the watchdog app
If i can see both the 12v and ev battery i be happy

Thanks

The drive battery is 300 Volts. The 12 Volt battery drives everything that a normal car has that's 12 Volts. It's small, as it only has to power up the electronics, not drive a starter motor. Some owners carry a small Lithium boost battery, just in case!

Whilst all this is true, its primary purpose is to fire up the operating system for the car - so if it is flat, you're stuck. Once the car is put into ready mode the main battery takes over and will maintain the 12volt just like a normal ICE car with the engine running.

However, just as in an ICE car, you wouldn't expect to be able to sit with the ignition on but without starting the ICE, a number of members of this forum have managed to run the 12v flat leaving the car switched on but not in ready mode and with heating, lights, radio etc. running!

 

[ThudnBlundr]

As soon as the car is turned on in Ready mode, the 12V battery will be being charged by the DC-DC converter, so any reading of the 12V battery voltage will be meaningless

 

[DerekT]

I had the same problems as described by the OP, with a Phev that I bought in February 2020, and I can confirm that the problems were caused by the 12V Auxiliary Battery dropping below 10.5V when left standing for a few days, not uncommon in these days of Lock-down, if it's in poor condition.

The car was 2 years old, with 5K on the clock; I too thought that was a good deal, until I checked the Service history, when I discovered that it had travelled about 20 miles in the previous 12 months! This means that the Aux battery had probably gone into deep-discharge, from which it could not be recovered. I eventually managed to get the dealer to replace the battery under warranty, but not without a fight! Had I seen the service history before I bought the car, I may well have passed it by!
I also discovered that when the Aux battery drops to that voltage, the car's charging system won't work either - setting the car up for a charge would lead to those same error messages!

It always started fine by jump-starting, using a small 12V Lead Acid battery, the sort commonly used in burglar alarms. So that's what I had to do until the garages re-opened in June, if the car were left standing for a few days.

This car replaced another Phev that I had for over 3 years, which never put a foot wrong.

Because the Aux battery lives in the passenger cabin, it's a bad idea (and probably prohibited) to use a cheaper wet-type lead acid battery in place of the AGM gel-battery that's used.

I am now waiting to see what effect the car's 12-month idle period may have had on the lithium-ion traction battery, which no doubt also went totally flat!

And I entirely agree with the OP's comments about the in-house mechanics....

 

[HHL]

I had the same problems as described by the OP, with a Phev that I bought in February 2020, and I can confirm that the problems were caused by the 12V Auxiliary Battery dropping below 10.5V when left standing for a few days, not uncommon in these days of Lock-down, if it's in poor condition.

The car was 2 years old, with 5K on the clock; I too thought that was a good deal, until I checked the Service history, when I discovered that it had travelled about 20 miles in the previous 12 months! This means that the Aux battery had probably gone into deep-discharge, from which it could not be recovered. I eventually managed to get the dealer to replace the battery under warranty, but not without a fight! Had I seen the service history before I bought the car, I may well have passed it by!
I also discovered that when the Aux battery drops to that voltage, the car's charging system won't work either - setting the car up for a charge would lead to those same error messages!

It always started fine by jump-starting, using a small 12V Lead Acid battery, the sort commonly used in burglar alarms. So that's what I had to do until the garages re-opened in June, if the car were left standing for a few days.

This car replaced another Phev that I had for over 3 years, which never put a foot wrong.

Because the Aux battery lives in the passenger cabin, it's a bad idea (and probably prohibited) to use a cheaper wet-type lead acid battery in place of the AGM gel-battery that's used.

I am now waiting to see what effect the car's 12-month idle period may have had on the lithium-ion traction battery, which no doubt also went totally flat!

And I entirely agree with the OP's comments about the in-house mechanics....

The traction battery would not go totally flat, even sitting there for two years. Li-Ion has a very low self discharge rate and when the car is turned off, there is a solenoid that disconnects it, so there would be very little parasitic drain.

 

[Katmandu]

In case you haven't found out from your own research and as there has been no clear information in this thread.

There is only one 12 volt battery and it is stored uner the rear luggage compartment on the right side and access there is really only for disconnection and/or removal.

A replacement battery is eyewateringly expensive because it is totally sealed as it is in the passenger compartment. Others are available but could only be used at your own risk e.g. health, insurance etc.

Jump starting and checking charge levels etc is done under the bonnet at the fuse box. Lift the fuse box lid and you will find a positive post under its own little cover and the earth point is any convenient body/engine contact point.

I have managed to leave a door open enough to flatten the battery twice and each time the car has been completely dead, propably just as well I had left the doors open. The first time I had a lesson from the breakdown man that attended and the second time I had a mini lithium jump start battery. As mentioned earlier in the thread the 12 volt battery simply powers all of the circuitry so no 12 volts and the car is dead, jump connect 12 volts and comes back to life, start the car and engage the permanent engine facility and the 12 volt battery will be recharged.

I would be very surprised if you 12 volt battery needs replacing but the brain of the breakdown man that didn't jump a 12 volt supply under your bonnet probly does.

Incidentally thanks for the warning about Milton Keynes thet is my next nearest agent after the one at Duxford and they are just as bad.

 

[DerekT]

The traction battery would not go totally flat, even sitting there for two years. Li-Ion has a very low self discharge rate and when the car is turned off, there is a solenoid that disconnects it, so there would be very little parasitic drain.

Thanks for that information.
I have read somewhere that if the Aux Battery is disconnected (or goes flat) for 'a long time', the BMU loses its information, and needs to be set up.
Based upon what the staff at my dealer appear (not) to know about these cars, I am not confident that this has been done (correctly).

I use the Torque Pro app to keep my eye on things.
The previous Phev I bought (2 years old) initially showed an EV battery capacity of 34.2 Ah; it would drop by 0.1 Ah each month or so, and then every 5-7 months it would go back UP by 0.3-0.4 Ah.
When I recently sold it, when it was almost 5 years old, it had fallen to 32.7 Ah (86.05% PMC) at 42,000 miles.

This car (also 2 years old) initially read 36.2 Ah when I got it on 10th Feb, but it dropped by 0.1 Ah every couple of weeks. Before I took it in for the Aux battery replacement on 20th July, it had dropped to 35.4 Ah. When I checked it after the Aux battery replacement, it had fallen to 34.9! And the next day to 34.8 Ah. Strange behaviour compared to the earlier car.

So we shall see what happens over the coming months.