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Hi all,
My Peugeot ion has reduced range (I'm down to 30's in this cold weather). Mileage is around 60k. Canion shows two cells looking weak, with a few others not far behind. I'm in North Wales and can't find anyone willing to have a look at it. Anyone know of anyone in the general area that might have a go?
Thanks
 

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Do you regularly run it down to two bars, leave it for 2 hours, then charge it fully, leaving it for a long time to balance? You can also unplug and replug to rebalance again.

Its suggested to do this at least once a month in the manual

This might help to give you back a few miles

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Discussion Starter #3
Thanks for the reply.
Yes, I do regularly do that, doesn't seem to make any difference. When it's re-balanced then run down, two of the cells in particular look very weak.
 

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How weak is weak, can you post a canion picture at about 20% charge? Some people have found that when they replace the bad cells the rest are not that far behind. Unless there is a massive difference it may not help that much.

I can do the job but i'm on the other side of the country ! TBH getting replacement batteries is a nightmare, only used ones are available and often fairly old. Im trying to source new replacement cells but its not easy, will probably have to get a battery made up of multiple smaller cells to meet the physical size, capacity and current rating required.

Are there any Hevra garages near you? EV-friendly garages in the UK

Cheers.
 

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To be honest i think your best bet and closest is going to be Indra.
Are you with a recovery company that does national recovery maybe...... ;)
 

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Hi all,
My Peugeot ion has reduced range (I'm down to 30's in this cold weather). Mileage is around 60k. Canion shows two cells looking weak, with a few others not far behind. I'm in North Wales and can't find anyone willing to have a look at it. Anyone know of anyone in the general area that might have a go?
Thanks
As Gary said - can you post the voltage graph from Canion when the pack has been discharged to close to 20% ? Also, what Ah figure is the BMS reporting now on the first page on Canion ?

I don't want to be a party pooper but I just went through a similar experience with my 2011 Ion, which co-incidentally is at about 60k miles now. My winter range is 35 miles with the heater on even if I drive conservatively, and worse if I drive "normally". Ah is currently 33.0Ah.

I started to notice a sharp decline in Ah over about 40k miles, for the full details have a read through the following thread, although you can probably skip most of it and start at the post which the link will take you directly to:


Three cells in particular looked much worse than the rest and I ended up replacing 4 cells myself with second hand ones. It was a big job that took me many days (albeit working in very cold, short winter days, partly outside, so I could have done it faster in summer) but I was able to do it myself, however it is not a job for the feint of heart or anyone who doesn't have a lot of DIY car repair experience - the biggest challenge is getting the battery down safely out of the car and back up in again - the actual disassembly of the pack and cell replacement once it is down on a trolley is comparatively easy although you do of course have to take great care of the high voltages as the pack is dangerous once opened even with the safety link removed. (You need to understand where you can touch and where you can't...)

The cells I fitted were second hand but tested prior to fitting and were all >40Ah usable, (and have subsequently proven to be the best cells in the entire pack once tested in the car, based on their voltage drop with discharge) however somewhat disappointingly the Ah capacity even after a full diagnostic tool calibration only went up by 1Ah to 34Ah and has ticked back down slowly to 33Ah again over the last three months, so I'm basically back where I started three months later as far as capacity and range go.

Some of the cells I replaced had high internal resistance as well which was slowing rapid charging speeds dramatically, the new cells don't have that problem so rapid charging speeds have gone back up to normal so in that sense it was worthwhile however there was basically no range increase.

When I look at the voltages of the cells now, it's clear that there's another 8-10 cells that while not as bad as the ones I replaced, are not too far behind them, hence those now became the weakest cells limiting the usable capacity. To make any meaningful increase I would have to replace another 10 cells and it's just not worth doing, especially if it only went up to say 36-37Ah.

I'd need to see the Ah figure and cell voltages at 20% SoC to be sure, but if your situation is the same as mine and there are several "weak" cells then I would say that it is not worth replacing them. It's a lot of work and effort and you're likely to see marginal or no improvement in range.

With multiple "faulty" cells you're probably not seeing faulty cells, simply cells that are close to the end of their cycle life - when they reach that point they still have a lot of life left but their capacity drops at a faster rate than the earlier part of their cycle life, this causes the better and worse cells to start to diverge in capacity. I have noticed this divergence behaviour over time on mine, as documented in that linked thread.

Another factor is that if the car is subject to frequent deep discharge (driving the car right down to a very low SoC) this degrades the weaker cells faster than the better ones, this causes further divergence because now the weaker cells reach a lower SoC than the better ones over a given driving cycle and suffer proportionally more degradation. Over time this magnifies any initial slight variances between the cells all out of proportion.

If you look at the low SoC voltage graph of a car that has done a high mileage but has not been frequently deeply discharged (most trips not below 50% SoC) the cells will all be very closely matched, unless one genuinely goes faulty. However a car that has been frequently pushed to its range limit will show a large divergence between its cells.

Post up your Ah figure and voltage graphs anyway so we can see them, however my advice is probably not to waste the time or money replacing cells, because unless you replace a lot of cells you're just pushing down bubbles in wet wallpaper... It's a lot of hours of work and if you're paying someone to do it that's a lot of money.

If the car can't meet your range needs any more then you're better to sell it on to someone who doesn't need quite as much range and replace it with something with a bit more. I'm in the same boat - I can't make my winter commute anymore without a 10 minute rapid charge on the way home, although to be fair it was marginal to begin with. I'm looking at selling it to replace it with something like a Leaf 30 for this and several other reasons.
 

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How weak is weak, can you post a canion picture at about 20% charge? Some people have found that when they replace the bad cells the rest are not that far behind. Unless there is a massive difference it may not help that much.
Exactly what I found, the hard way. The divergence in capacity is unfortunately to be expected with cells that have reached their cycle life - they will continue to work well past that but degradation rate increases considerably compared to the earlier part of their life. When different cells hit this point at different times the divergence can make some cells look "faulty", but really they've just reached their cycle life "knee point" a bit earlier than some other cells, which will soon follow.

I would say only if an individual cell is clearly faulty would it be worth replacing it. Replacing a few that are "weak" hoping to regain significant capacity and range is probably a waste of time and unfortunately I have first hand experience of this.
I can do the job but i'm on the other side of the country ! TBH getting replacement batteries is a nightmare, only used ones are available and often fairly old. Im trying to source new replacement cells but its not easy, will probably have to get a battery made up of multiple smaller cells to meet the physical size, capacity and current rating required.
I was able to source four good second hand cells from Second Life EV batteries - I still capacity tested them myself to verify they were good, the ones I received were all between 40-43Ah usable depending on what voltage cutoff I chose to measure to, and were well matched, and have proven to be better than even the best cells in my pack once in the car. They seem to always have some in, and were quick to send them. The only thing I would complain about is they did not package them very securely so if the postie had dropped them they would have been damaged... :rolleyes:

So getting the cells is not the issue, it's deciding whether there is actually a "faulty" cell or whether it is just normal degradation spread as a result of lots of deep discharges.
 

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If you're going to the effort of changing a faulty cell you may as well replace all the cells with 60ah samsung sdi cells (same size with 3mm or so). The sdi cells are the same as used in the bmw i3, however you can't reuse an i3 pack without some dificulty as the bus bars are laser welded not bolted connections.

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If you're going to the effort of changing a faulty cell you may as well replace all the cells with 60ah samsung sdi cells (same size with 3mm or so). The sdi cells are the same as used in the bmw i3, however you can't reuse an i3 pack without some dificulty as the bus bars are laser welded not bolted connections.
The sensible thing to do is sell the car and buy something with significantly more range... ;)

Early EV's with small batteries are going to suffer from significant degradation, there's no way around it... It's best to get your use out of them and move them on before the loss of range becomes too significant. As long as the new owner buys it knowing what the useful range is then it's no different to buying any old car that is starting to wear out in some way - you buy an old car for a cheaper price knowing that it is more worn out and has less useful years of life left. That's the trade off.

By the time things like e-Niro's are getting on in age and cheap it won't be nearly as much of a problem as the much larger, liquid cooled batteries will last far, far longer, and perhaps even outlast the mechanics of the car. But that's not true of early EV's with small batteries lacking proper thermal management.
 

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Was about to say there is this company that have cropped up before...

But if the BMW cells could help or be salvaged it would be a start to increase capacity but as time goes on ideally more dense cells will come out and being a lightweight car with aircooled battery it will help a little.
 

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Make up slabs of 21700 Samsung-40t (these seem the best commodity cells out there at the moment) and drop those in instead.
 

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Make up slabs of 21700 Samsung-40t (these seem the best commodity cells out there at the moment) and drop those in instead.
This is a decent approach however those cells dont have a high enough charge rate for full regen or chademo charging - they wouldnt last long. Other cells could work this way, it gets expensive if you need a lot of cells as high charge rate cells are expensive (and its a fair bit of work to build the cell packs).

Cheers
 

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This is a decent approach however those cells dont have a high enough charge rate for full regen or chademo charging - they wouldnt last long. Other cells could work this way, it gets expensive if you need a lot of cells as high charge rate cells are expensive (and its a fair bit of work to build the cell packs).

Cheers
They're 35a discharge rated and 6a charge rated - how many could you fit in parallel into the space occupied by an LEV40 cell? I don't know the dimensions of the LEV40 to compare.
 

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They're 35a discharge rated and 6a charge rated - how many could you fit in parallel into the space occupied by an LEV40 cell? I don't know the dimensions of the LEV40 to compare.
Its a lev50, you'd need something more like a Molicel P42A, that can handle 8.4A charge current under the right curcumstances. You'd probably get 12 or 14 in the space max and to give them a decent lifespan you'd need them to accept at least 6A charge rate.

Cheers.
 

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Its a lev50, you'd need something more like a Molicel P42A, that can handle 8.4A charge current under the right curcumstances. You'd probably get 12 or 14 in the space max and to give them a decent lifespan you'd need them to accept at least 6A charge rate.

Cheers.
Interesting.... Looks like a good cell, is volume pricing any good? I just got quoted $3.90/cell on the samsung's from queen battery with shipping DDP for $235 on qty. 360 cells.
 

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Does anyone know how the temperature sensors for the cells work on these cars ? I've had my pack apart, removed some CMU boards in the process of swapping some cells and I was not able to identify the cell temperature sensors, and every 3 out of 4 cells has a sensor...

The best place to measure the temperature would be on the flat part of the battery terminal beside the threaded rod, and I had assumed that there would be a thermal sensor that pressed down onto that tab, but there was nothing making physical contact, apart from the screw connecting the voltage reading to the LTC, which just went to a PCB trace.

Does it use a closely spaced infrared sensor pointing directly at the flat part of the terminal ? Or perhaps at the body of the cell itself ? This seems feasible but perhaps a little problematic as while the terminal is a relatively good heat conductor (thus being representative of the temperature of the current collectors inside the cell) metal has a low and somewhat variable emissivity depending on its finish - shiny or rough and tarnished etc... the plastic film over the outside of the cell would have a stable near 1 emissivity and be a good candidate to point an IR sensor at however as an insulator it would not be as hot as the metal post.

Obviously knowing how the temperature sensors work is critical to fitting after market cells, especially something like trying to stuff a bunch of 18650's in each compartment. It would not be at all safe to try to use after market cells of a different configuration with no temperature monitoring of the cells to control charge rate in very cold and hot conditions etc...
 

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Does anyone know how the temperature sensors for the cells work on these cars ? I've had my pack apart, removed some CMU boards in the process of swapping some cells and I was not able to identify the cell temperature sensors, and every 3 out of 4 cells has a sensor...

The best place to measure the temperature would be on the flat part of the battery terminal beside the threaded rod, and I had assumed that there would be a thermal sensor that pressed down onto that tab, but there was nothing.

Does it use a closely spaced infrared sensor pointing directly at the flat part of the terminal ? Or perhaps at the body of the cell itself ? This seems feasible but perhaps a little problematic as while the terminal is a relatively good heat conductor (thus being representative of the temperature of the collectors inside the cell) metal has a low and somewhat variable sensitivity depending on its finish - shiny or rough and tarnished etc... the plastic film over the outside of the cell would have a stable near 1 emissitivity and be a good candidate to point an IR sensor at however as an insulator it would not be as hot as the metal post.

Obviously knowing how the temperature sensors work is critical to fitting after market cells, especially something like trying to stuff a bunch of 18650's in each compartment...
The temp sensors are just on the CMU, with another 3 on the extra board for an 8-cell pack. So it doesnt directly monitor the battery temperature as its not on the battery, its more of a guide for the car to turn on AC, reduce charge rate, etc.

Cheers.
 
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