[smithgt]

Hi,
I'm looking at a couple of cars, both are from 2012.

One has only travelled 7,000 miles, and only travelled 600 in it's first five years! and then 3,500 a year for the last two years.

The other is 30k with a more average usage pattern, of 5-8kper year.

Should I be concerned about the battery capacity or SOH and is there anyway I can check once I have access to the vehicle?

thanks

 

[Scrooge]

If cars are not used then tend to develop problems so concern over the battery is not the only thing to think of. Also, check the general condition and the maintenance schedule of each vehicle. There are apps around that connect to cheap a Elm 327 adapter giving battery condition. Personally I have not tried them as I'm IOS not android. Many on this site have vast knowledge so hopefully, you will get a response.

 

[DBMandrake]

The best app to use for the i-Miev/C-Zero/Ion is Canion which is free however it requires an Android device and an OBDLink LX adaptor or similar to use - it won't work with the cheap and numerous ELM327 adaptors as it only works with adaptors based on the STN11xx chipset family.

A car that has done extremely low mileage for its age may have been left sitting at full charge for a lot of that time, this would degrade the battery significantly, and potentially more than a higher mileage car, as a lot of battery degradation is age related and is accelerated by being left at a high state of charge.

For a higher mileage car depth of discharge affects degradation a lot.

A car like mine which has been routinely discharged to a low SoC due to driving near its range limits will lose capacity faster than one that does shorter trips that do not deeply discharge the battery - but there's no way to know what the previous owner(s) driving habits were.

Personally I would want to see the Ah capacity of the battery using something like Canion before buying. (I would say the same of any second hand EV)

Canion doesn't report SoH in percentage it only gives an Ah figure, however brand new Ah is about 46Ah, so just take the reported Ah figure and divide into 46 and take a percentage, so if it said 38Ah, (38 / 46) * 100 = 82.6% SoH.

Something like an OBDLink LX is a good investment though because as well as Canion, it should work with all the other apps for other EV's that are available, such as Leafspy for the Leaf and so on, as it also emulates the ELM327 1.4a command set. OBDLink also provide free firmware updates to add new features and fix bugs and have good technical support whereas with many cheap Chinese adaptors you'll be lucky to even get a replacement for one that doesn't work properly let alone good technical support, and many are fake or do not support the ELM command set version they purport to.

So if you're in the market for an EV but aren't sure which you might buy yet it would let you check the battery health of most potential EV's by simply downloading the approprite app. Given the cost of a car purchase spending about £40 on a diagnostic adaptor to make sure you don't get a lemon makes good sense I think.

 

[freddym]

Just keep in mind the Mitsubishi programmed in a fixed battery capacity reduction rate into the BMS. MY battery now shows a high AmpHour reading at 48000 Kms than it did at 13000 Kms when Canyon was first connected to the car.

My advice would be to forget the old triplets and get something with newer battery chemistry, I forget the year of introduction, someone will post. The later battery chemistry cars also have a redesigned onboard charger and 12v dc-dc converter so less chance of expensive problems. Plus they have better heaters.

 

[smithgt]

Canion doesn't report SoH in percentage it only gives an Ah figure, however, brand new Ah is about 46Ah, so just take the reported Ah figure and divide into 46 and take a percentage, so if it said 38Ah, (38 / 46) * 100 = 82.6% SoH.

Thanks - Have ordered the LX from Amazon.

Do the same calculation values apply to a 2015 vehicle where there are 80 cells over the original 88?

 

[freddym]

The cells are in series so the battery has the AmpHour capacity of the weakest cell but the voltage of the sun if the cells. The 88 cell battery will have a higher voltage than the 80 cell battery.

 

[DBMandrake]

Thanks - Have ordered the LX from Amazon.

Do the same calculation values apply to a 2015 vehicle where there are 80 cells over the original 88?

Yes, the same Ah figures apply, with 46Ah still being 100% SoH. However as freddy points out the voltage will be lower - full charge on an 88 cell pack is 360.8 volts, on an 80 cell pack its only 328 volts.

So each Ah is worth less energy (kWh) on the 80 cell pack, as power is voltage x current. In theory a new 88 cell pack was 16kWh and the 80 cell pack was 14.5kWh, however it doesn't take long for the older cell type to degrade below 90% SoH and if the newer type degrades more slowly as promised (I don't think anyone has any hard data on this) then after a few years the newer type pack will have more useable capacity and range left despite starting with less when new.

I've seen fairly substantial degradation on my 2011 model with old cells - it was at 39.9Ah at 6 years and 28k miles, its now at 32.5Ah at 9 years and 60k miles. However mine has been driven to near its maximum range on a daily basis every winter and this is hard on the cells. A car which has had an easier life and hasn't been deeply discharged regularly probably wouldn't degrade nearly as much and there are Ion's/C-Zero's similar age and mileage to mine with a lot less degradation - probably down to driving circumstances.

My takeaway from this is that it's false economy to buy an EV which doesn't have much range buffer for your regular journey. If you want the battery to last a long time, ideally get something that can do your daily commute with at least half the battery remaining at the end of the day, (in winter!) this is much easier on the cells, as well as avoiding range anxiety and allowing the car to still make the journey comfortably when there is eventually some degradation.

Of course in the current market climate where long range EV's are still expensive and/or hard to come by, it's not always possible to live by this advice, but it will get easier over the next few years.

 

[smithgt]

Thanks - The daily usage is 25miles return, followed by two hours at home then 12miles return. So I'm hopeful that the ION will work okay without the need to charge during the day.

 

[DBMandrake]

It depends on what SoH the battery has and what speed you drive at of course, but to give a rough idea, when mine was at 39.9Ah I was getting 63 miles in summer with the heater off and 42 miles in winter with the heater on high based on my work commute which is mixed residential/city/motorway. If the Ah capacity is worse or better scale those figures accordingly.

37 miles in winter is going to be tight in my opinion. That's pretty much exactly what I do and while I could make it in winter initially, with the degradation over time I'm now having to top up with a 5-10 minute rapid charge on the way home to get home comfortably. At 32.5Ah I'd say my realistic range (to tortoise mode) is about 54 miles in summer and 37 in winter with the heater on.

These cars do not have a heat pump so the resistance heater has a huge impact on the range of up to 30-40% vs leaving the heater off.

 

[richi]

Another data point: 2012 i-MiEV with 48,000 miles, BMU reports 38.5 Ah. True winter range is 65 miles of mixed non-motorway driving (less with heater).

After her 35 mile commute with heater on, SWMBO typically gets back with about 5 or 6 blobs (out of 16). She is not a hypermiler ?

 

[dk6780]

Thanks - The daily usage is 25miles return, followed by two hours at home then 12miles return. So I'm hopeful that the ION will work okay without the need to charge during the day.

On the assumption that you will charge in the "two hours at home" you should be fine as that should add at least 20 miles range on a wall charger. However, if you cannot rely on charging you'll be marginal as short journeys in winter will significantly impact on your range. As an aside and not triplet bashing, but my Wife can reduce the range of her LEAF24 to under 60 miles despite having 19kWh with her series of short but fast journeys with the heater and AC on for demist.

 

[DBMandrake]

Another data point: 2012 i-MiEV with 48,000 miles, BMU reports 38.5 Ah. True winter range is 65 miles of mixed non-motorway driving (less with heater).

After her 35 mile commute with heater on, SWMBO typically gets back with about 5 or 6 blobs (out of 16). She is not a hypermiler ?

I could only dream of doing 35 miles in winter and having 5 bars left.... my car hasn't even managed that when I first bought it at 39.9Ah. If I left the heater off, sure, but heater on, no way.

Part of that might be that my trip each way is broken into two with a 15 minute wait, this gives time for the heater to cool down. Also there are always two people in the car plus a child for part of the journey.

People's attainable mileage can vary greatly in any EV depending on driving conditions so this large variance needs to be taken into account by prospective purchasers when considering whether a car can meet their needs or not. If range is marginal you also have to allow for things like surface water and headwinds which can easily wipe a few miles off your normally attainable range on specific days. (Let alone diversions in traffic due to accidents etc requiring more range)

This is why I don't advocate buying an EV where the range is only "just enough" before degradation over time has occurred. My next purchase is probably going to be a Leaf 30 which should be able to do my commute with more than 50% of the battery remaining even winter. (Partly thanks to a heat pump) This will be a game changer for me and I can't wait to be honest.

 

[richi]

Really @DBMandrake? That's fascinating. I wonder if my BMU is under-estimating the true SoH? I'm almost positive she gets home with 7–8 blobs in warm weather (no heat nor aircon). Her 35-mile commute is of course also split in two (there and back, with several hours parked).

It is of course possible I've misremembered the number of blobs she gets home with. I'll check again when she's back tonight.

 

[DBMandrake]

Really @DBMandrake? That's fascinating. I wonder if my BMU is under-estimating the true SoH? I'm almost positive she gets home with 7–8 blobs in warm weather (no heat nor aircon). Her 35-mile commute is of course also split in two (there and back, with several hours parked).

My morning and evening commutes are both split into two separate journeys so I have effectively 4 short journeys per day, so cold soak would be more than if it was just two journeys a day.

Warm weather with no heater ? yeah, I used to get home with 7 bars in summer with no heater. Now it's more like 4 bars after degradation. Winter with heater I used to get home with 2-4 bars, now I can't make it without the heater turned off for the last 10 minutes (and maybe 2 miles left when I get there) or a small rapid charge.

 

[Scrooge]

This is why I don't advocate buying an EV where the range is only "just enough" before degradation over time has occurred. My next purchase is probably going to be a Leaf 30 which should be able to do my commute with more than 50% of the battery remaining even winter. (Partly thanks to a heat pump) This will be a game changer for me and I can't wait to be honest.

Yes, a Leaf30 would be perfect. I had one on a four-day test drive and the much longer range would be very welcome not just so I'm not cutting close on the range but as others have said to me, store more free leccy Oh and it's much more comfortable. But being a tight arse I can't see that happening soon, lol.

I also had the eGolf on an extended test drive but for the huge price premium could not really see what more it offered.

 

[richi]

@DBMandrake I just checked: 5 blobs today. GOM says 21 (heater off).

She used the heater on her return, but not her outbound trip.

 

[Scrooge]

My commute is 27 miles each way, 54 miles. No issues covering that distance starting at 100% with 2/3 bars left. No heater even though it's winter. 11 miles country roads, 16 miles major A road. Normally though I'll plug the car into a destination/rapid at some point in the journey to get extra range for the evening

 

[DBMandrake]

All you no heater in the winter chaps apparently don't have a child and spouse in the car with you that feel the cold.

 

[richi]

@DBMandrake I gave you a slightly bum steer: Her round-trip is actually 32 miles (she changed route). Roads are a mix of 30–50 mph country and suburban, not during rush hour.

 

[smithgt]

It's collection day tomorrow.

So assuming that the battery health is okay then it looks like it will be wet and windy for the 90 mile drive home!

Any guestimates as what kWh I should expect to find after 5yrs and 26k miles?