PHEV watchdog state of health doesn't match the dealer's health check, suspicious or not?

[adrianvdb]

I'm currently in the process of buying a 2013 Outlander PHEV. I brought an OBD dongle with me for the test drive and plugged it in. I was surprised to find a state of health of 91% (!!!) It has 36.6 Ah left. Maybe it had the batteries replaced not long before it got imported? I used the PHEV Watchdog app to check.
Anyway, to be on the safe side, I asked the dealer to do a professional health check on the battery, it came back at 76.1%.
It doesn't sit me well, because earlier on, when I hadn't had my eye on a specific outlander yet, I mentioned I didn't want to buy anything below 75%. Now it comes back to be 76%... Coincidence? Anyway, I don't know if I'm being paranoid here or there could be a logical explanation for this? Does anyone know how the health check works? I always thought that was a simple OBD check too, but it might be something more elaborate... Or they saw a new battery and quickly scooped it up from under my nose.

What are your thoughts?

Thanks

 

[amiralnar]

"Maybe it had the batteries replaced not long before it got imported"

It's very easy to find out this. Just lay down on the ground and look at the battery sticker.

Show the screenshots from watchdog at 91 and 76 SOH. It will clear everything.

"What are your thoughts?"

Seller f**d up you and reset BMU

 

[greendwarf]

I'm confused by both question and the answer!

Have you tested the battery again since the dealer did his test?

Does the asking price reflect the likelihood of having a new battery?

Even if it had one and the dealer has gone to all the trouble of swapping it out, you've got no complaint - it is his car until you agree a deal!

Why would the dealer do a BMU reset to bring down the battery health and potentially undermine the sale?

As I always say about battery health, these figures are irrelevant anyway. The only way to test it properly is to drive it at urban speeds in a flat topology and see how far a full battery will take you. :idea:

 

[jaapv]

assuming the brake calipers don't stick, that it is not cold to make the electric heater kick in, the aircon is switched off, etc (not to mention skill driving an EV )

 

[greendwarf]

But most people buy a car to drive - so how far YOU can drive it (irrespective of the factors you mention) is what a buying decision should be based on not some figures read off a dongle. Especially as the OP already mistrusts the results.

 

[adrianvdb]

Hi, thanks for the replies, awesome to hear your view on things.

Just to get back on some of your comments.

@Amiraldar
The dealer didn't say anything about the SOH when I came in for a test drive. I plugged in the dongle and read 91% SOH. I asked for a battery check (I never used the watchdog before and just wanted to be certain the numbers matched), and the battery check came back at 76%. Not bad for a 2013 model, but it's not what I read with the OBD dongle. The dealer never claimed 91%.

@Greendwarf
Have you tested the battery again since the dealer did his test?
I'll test it again soon. I ended up buying the car anyway, because it was the best value for money I could find. I'm just curious why the OBD reading came back different compared to the battery check!

Does the asking price reflect the likelihood of having a new battery?
I'm afraid the asking price was reflecting a market shortage of these vehicles in NZ :? There were two cars available in my region. Both were sold and I ended up buying the one they hadn't advertised yet... They're gaining popularity, that's for sure!

And regarding your last comment, I was in the market for a secondhand PHEV, so ideally I'd get the best battery SOH for my budget ;-)

Hope this clears some things up. I will get back with some photos soon.


Thanks for the help, much appreciated!

 

[amiralnar]

Hi, thanks for the replies, awesome to hear your view on things.

Just to get back on some of your comments.

@Amiraldar
The dealer didn't say anything about the SOH when I came in for a test drive. I plugged in the dongle and read 91% SOH. I asked for a battery check (I never used the watchdog before and just wanted to be certain the numbers matched), and the battery check came back at 76%. Not bad for a 2013 model, but it's not what I read with the OBD dongle. The dealer never claimed 91%.

Well if you can post here wachdog detailed info under soh record then we can find out what really happend

 

[adrianvdb]

Hi,

I found out that the OBD dongle still reads the same 91% SOH, so it doesn't seem like the battery pack has been swapped.

So, that boils down to the big question: why does the battery check from the dealer come back at 76% SOH, while the OBD read-out shows 91% SOH?
I have to admit that I'm not super confident on how to interpret all the data from the PHEV watchdog.

@amiralnar I hope these were the screenshots you were hoping for. Thanks for actively following this thread!

 

[jaapv]

The dealer does not measure the SOH by simply plugging in a dongle, there is a procedure as set out by Mitsubishi, so no surprise at varying results. This only shows the lack of reliability of Watchdog. I would take the dealer measurement as correct, especially given the mileage. 91% is even good for a brand new delivery mileage car.

 

[adrianvdb]

@jaapv, I did not know that, that would indeed explain what would have happened. Do you know roughly what that procedure would look like, or where I can find out? Just curious to hear more about it.

I think that solves the mystery =) Thanks everyone!

 

[amiralnar]

Hi,

I found out that the OBD dongle still reads the same 91% SOH, so it doesn't seem like the battery pack has been swapped.

So, that boils down to the big question: why does the battery check from the dealer come back at 76% SOH, while the OBD read-out shows 91% SOH?
I have to admit that I'm not super confident on how to interpret all the data from the PHEV watchdog.

@amiralnar I hope these were the screenshots you were hoping for. Thanks for actively following this thread!

Well it's look like this is a good brand new battery, replased this year.
To confirm that look at barcode sticker on the lateral side of the battery. It should be something like 20/01 to 20/12

 

[greendwarf]

If the last picture is the dealer's result then the Watchdog results of 36.5 & 91.3&% are there - just not together.

 

[Daixiwen]

Your screenshot from Phev watchdog shows 346 days for the age of the battery. If it hasn't been swapped, it means that someone did a BMU reset about a year ago without properly reprogramming the BMU, and most probably without doing a dbcam afterwards to measure the actual battery capacity. And in that case yes, the capacity reported by the BMU (and Phev Watchdog) is higher than the actual one.
I'd definitely look on the side of the car and check the actual manufacture date of the battery to be sure.

If it's indeed the old battery and the reported capacity is wrong, you can drive the car like that (and it has for almost a year!) but you risk damaging the battery by discharging it more than what was designed. If possible you should take it back to your dealer and ask him to do a proper battery calibration procedure (see A.2 here: https://www.richi.uk/p/mitsubishi-outlander-phev-faq.html#phevfaqA ) and then both the dealer and phev Watchdog should report the same capacity.

 

[adrianvdb]

Thanks Daixiwen! I haven't driven it for 50km purely electric yet, so I'll see if I can get a number on actual driving range on the battery. For what it's worth, the board computer tells me I've got 51 km range when it's fully charged.

I think I found the sticker you were talking about, hope it's the right one. I attached it below.

The previous screenshots I posted were both from the PHEV watchdog app. The dealer gave me a shitty piece of paper stating 76% state of health, with all the fields like make, model, VIN, etc. left blank... :roll:

I'm very curious to hear now if I've found the right sticker, and if the 20/12 translates to December 2020... If so, that that mean that I accidentally found an old car with a new battery? That also means the dealer ripped me off by not testing the battery but giving me a dummy piece of paper.

 

[Daixiwen]

Yes,it definitely looks like you really got a one year old battery! Congratulations! Now the question is how the dealer got that strange battery health report.

 

[adrianvdb]

Hi,

Let me show you the battery test report the dealer gave me. I reckon they took an old one and removed the manufacturing year, type and VIN from the form. Anyway, I'm this turned out all right, but I won't be buying another car from them!

Just an FYI, I love the car, it's going great! No regrets yet buying the Outlander PHEV

 

[Daixiwen]

The battery capacity in Ah matches almost the value from Phev Watchdog and it's probable that the BMU decreased the capacity by 0.1 Ah between when the dealer printed the paper and when you got the battery health report on your phone. So the dealer probably just extracted the capacity from an ODB reader, just like you did.
I have no idea what "battery capacity sustainability" actually means, maybe someone else knows? But the reported 36.6Ah is 91.5% of the original 40 Ah capacity, not 76%

The dealer clearly has no clue, but there doesn't seem to be any discrepancy if you look at the correct value. It's still rather strange he didn't know the battery had been replaced.

Enjoy the car

 

[adrianvdb]

Wow, I completely missed that fact, I didn't think about comparing the amp hours, instead I've tunnel-visioned on the state of health. But you're right, it says "battery capacity sustainability". I've never heard of that before, and they definitely sold it to me as a state of health, as that was explicitly what I asked for, and what they sold me.

Anyway, that was an interesting plot twist, and I think you're right.

I have no clue what "battery capacity sustainability" means, but this website explains it like this:

Mitsubishi PHEV, battery cell data down loaded, battery capacity sustainability test (battery life remaining), Mitsubishi states 8-10% depreciation over the first year from new then approxiatemly 4% depreciation every year after.

Source: https://www.incarautomotive.co.nz/

That does make it sound like State of Health to me... Maybe they calculated it based on the newer, bigger 13.4kWh battery packs?