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Discussion Starter · #1 ·
Hi All Renault zoe users, I have a easy way of finding state of health (SOH) of Renault zoe traction battery. Normally you need to take the zoe to a dealer for diagnosis report which costs too much or you need to use a specific OBDII dongle to connect and get data out from the onboard computer (bit dangerous as it could damage the zoe).
I have found a easy way to find the SOH. Here are the steps.
1. Note the percentage battery left P seen on dashboard when you unlock your zoe.
2. Reset the range using any method. It is very easy. Refer to YouTube videos for this
Note the new range as R.
3. Look for your zoe's manufacturer's ideal advertised NEDC range for your zoe- IR. It is either 130 or 230 or 250 depending on model. Zoe wiki has it.
4. Then use this simple formula I have derived.
SOH = R x 10000 / (P x IR)
Hope it helps
Do let me know if you found this useful
Enjoy!
Nat
 

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Zoe R110 ZE40
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Have you done any comparisons with the value of SOH that is calculated by the battery? Are you saying that the Zoe uses SOH when setting the range after reset? I thought that value always ended up the same. I suspect you mean WLTP rather than NEDC by the way - as for my ZE40, WLTP is 186miles, NEDC was 250 miles. Using the NEDC figure is miles off the SOH value in the battery using your formula!
 

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Discussion Starter · #6 · (Edited)
Have you done any comparisons with the value of SOH that is calculated by the battery? Are you saying that the Zoe uses SOH when setting the range after reset? I thought that value always ended up the same. I suspect you mean WLTP rather than NEDC by the way - as for my ZE40, WLTP is 186miles, NEDC was 250 miles. Using the NEDC figure is miles off the SOH value in the battery using your formula!
When you reset your ze40 what is the new range you get? On a 100% charge do you not get 200+ miles? If it is above 186, it has to be NEDC figure that you get after the reset.
 

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Co-author of CanZE. Q210 nov 2013
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A few remarks if I may
  • CanZE only works in read only mode. It will write nothing. The only exception being the IDs for TPMS so you can have winter and summer tire sets, and clearing DTCs. Ask me how I know ;);
  • There is hardly a "specific" dongle needed, though most sub 10 quid ones are so crappy they indeed don't work. Not true for the sub 20 ones and and electronics hobbyists can build a super fast one fir sub 30;
  • Don't get me wrong, if SOH is the only thing you want to know, use the described method, though for ie considering a buy "on the driveway", the required full charge can be the proverbial other side of the coin;
  • At least for the Ph1 models, you have to actively fiddle a few things in the car things to allow certain writing. Haven't tried Ph2 (I do not own one), but the added box called the "security gateway" to the OBD2 connector suggests it has not been made easier (wink wink). I cannot vow this is true for all the writing, but it is for clearing DTCs. I think @Andy-Zoé-User has more experience on this subject.
  • The method described works AFAIK for the Ph1, but not for the Ph2 battery (which has a totally different internal computer). I gladly would stand corrected on that.
Hope this helps.
 

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Discussion Starter · #8 ·
A few remarks if I may
  • CanZE only works in read only mode. It will write nothing. The only exception being the IDs for TPMS so you can have winter and summer tire sets, and clearing DTCs. Ask me how I know ;);
  • There is hardly a "specific" dongle needed, though most sub 10 quid ones are so crappy they indeed don't work. Not true for the sub 20 ones and and electronics hobbyists can build a super fast one fir sub 30;
  • Don't get me wrong, if SOH is the only thing you want to know, use the described method, though for ie considering a buy "on the driveway", the required full charge can be the proverbial other side of the coin;
  • At least for the Ph1 models, you have to actively fiddle a few things in the car things to allow certain writing. Haven't tried Ph2 (I do not own one), but the added box called the "security gateway" to the OBD2 connector suggests it has not been made easier (wink wink). I cannot vow this is true for all the writing, but it is for clearing DTCs. I think @Andy-Zoé-User has more experience on this subject.
  • The method described works AFAIK for the Ph1, but not for the Ph2 battery (which has a totally different internal computer). I gladly would stand corrected on that.
Hope this helps.
I use ddt2all with konnwei dongle for my 2014 zoe. It allows read and write so extra care is needed. Never dared to write yet. The formula works very well for this version.
I think SOH % is the most important thing to know the battery capacity because it is independent of driving style related range.
Hope it makes sense.
Thanks
 

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Co-author of CanZE. Q210 nov 2013
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4,856 Posts
This effect is no indication of cells dying. If a cell is dying you will see it's cell voltage differ from the mean and the LBC trying harder and harder to balance the pack. In CanZE you can see this through thg "Voltage map" screen.

SOH is usually presented as capacity stated in Ah (not in kWh), related to the nominal Ah capacity. Li-Ion cells are very "coulomb efficient", meaning the actual coulomb charge (iow, number of electrons) that you put in, will almost 100% come out again. Most losses are because of internal resistance, with a lower discharge voltage as effect. Still, this Coulomb efficiency is also slightly affected by temperature.

Other than that, do not forget that SOH is "just a number computed by the LBC", there is no physical inspection of the chemistry. Sure the LBC integrates measured current flow, but it does almost never have a neat full charge discharge cycle to it's disposal, so it uses estimations based on voltage profiles and adjusts it's algorithm parameters at the far end of the the cycle. For most cars, a full charge is very often reached, but full discharge is not. This is why I see my SOH jump around by roughly 2%.

Finally, the different firmware versions seem to have some subtle computational differences too, though that is more or less irrelevant if you want to follow degradation of your own pack.

About the KONNWEI Dongle: we have found it quite slow, but stable compared with most other cheaper brands or fakes. Almost all use some form of older ripped ELM327 firmware. DDT4ALL is a very nice piece of software, though it is aimed at people who basically know what they are doing. CanZE is more for the average interested end user and I personally regard it more as my "advanced dashboard". But that is me.
 

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Zoe Devotee
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🤷‍♂️ Is this groundhog day? We found out how to calculate SOH based on displayed range back around 2017 did we not and WLTP and NEDC was not the way (it was trip B results from a number of brand new cars)? I do vaguely recall myself and @yoh-there discussing this quite a lot on the forum. Alongside working the formula with actual figures from CanZE and the iCarsoft code reader I purchased for this very testing.

I expect "youtube content" robbery from Nick, even that Ric Mayall Vyvyan sounding Julian guy, but now it seems to just have become Mandalorian in real life - "This is the way!" :ROFLMAO:
 
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