Juanjo Madrid's cell replacement thread

[piev]

Don’t think the BMU is VIN coded, otherwise below would not have worked:

https://myimiev.com/threads/miev-with-c-zero-parts.5521/

Afaik VIN programming is only required for ETACS-ECU, EV-ECU and MCU..

You may be correct. I do know that it has information in it like serial number and model number software version etc. I would have to look it up because I can't remember specifics. Of course, I don't know if the ECU uses this information, so it may work to swap them. Maybe I will try it next time and see. I just finished my second upgrade. Did the whole thing in less than 20 hours.

 

[MickeyS70]

You may be correct. I do know that it has information in it like serial number and model number software version etc. I would have to look it up because I can't remember specifics. Of course, I don't know if the ECU uses this information, so it may work to swap them. Maybe I will try it next time and see.

It does work, see post #225
https://myimiev.com/threads/battery-pack-change-plans.5525/page-12

 

[Juanjo Madrid]

Do you have dimensions of these cells to share? Do they have the threaded holes for the CMU boards to mount?

This drawing is started to see the difference in measurements between LEV and CATL because my plans were to use 2 LEV50N and 2 CATL93, I'm not sure if the measurements are correct because in the middle of this, I saw all the measurements on this forum and I remember mixing my measurements and the measurements on this forum.

I think the LEV50 and the LEV50N are the same, but I'm not 100% sure. The only thing I can tell you is that I thought the LEV50N was perfectly fixed in my packs and there was no problem with the CMU fixing on it, I had to make the separations between cells because my LEV50N had nothing to ensure they were pressed and I transferred the originals to the LEV50N, I put some photos of my mixed LEV/LEVN cells, the differences I observed (height) I attributed to the use and possible inflation of the old ones

 

[Volt Energia]

Juanjo .. Boa Tarde ..

Tenho um MIEV 2012 aqui no Brasil e vou precisar trocar o conjunto de baterias daqui a algum tempo.
Você já recebeu essas baterias que adquiriu? E já instalou no carro?
Vou ter que importar também daqui a algum tempo..

Obrigado Adalberon

 

[Juanjo Madrid]

Hi, I not have the battery yet, when arrive I put images here, I expect 90Km around because promise matched and around 35-40Ah.

 

[Volt Energia]

Olá, ainda não tenho a bateria, quando chegar coloco as imagens aqui, espero rodar 90 km porque a promessa foi cumprida e em torno de 35-40 Ah.
View attachment 1685

Janjo
Tudo em paz ?
Obrigado pela atenção
Estou curioso para ver o resultado da troca das baterias.

Seria possível me enviar a especificação exata desta bateria e qual foi a empresa fornecedora.
Eu já vou iniciar as negociações de compra..

obrigado

 

[Juanjo Madrid]

Janjo
Tudo em paz ?
Obrigado pela atenção
Estou curioso para ver o resultado da troca das baterias.

Seria possível me enviar a especificação exata desta bateria e qual foi a empresa fornecedora.
Eu já vou iniciar as negociações de compra..

obrigado

Hi, the batteries was buy with the help of a friend with company in Hong Kong, around 2400€ in my House, I not pay transport because my friend buy Power bank to this company every two months and put in their container from HK to Málaga and send me to Madrid, I wait around two month to arrive to my House,, are the original LEV50N, the same model of the I-miev afther 2013, are used batteries around 37-40Ah measures from minimal to maximal voltage at 6 A current of charge/discharge, 1,3 mOhm to 1,6mOhm. Im balancing and tested now all the group and hope put in my pack around 20 days if the wheater improve. I put here the result of my test here. I unknow the supplier company, are Dismantling storages, not are manufacturer like you can see in Alibaba or AliExpress. Have around 12000 pieces, if my test and result are ok, my friend say me we could do import in Big quantities to improve the price (and profits), I think a good objetive could be 2000€ in any EU destination, more price is really stupid from the CATL 93 option is available.
Juan

 

[Juanjo Madrid]

The better of used LEV50N option is the lower price and this cells are the original parts, no need busbar mod, if you not need the double of the original range maybe is a good option for you.

 

[Volt Energia]

Olá, as baterias foram compradas com a ajuda de um amigo com empresa em Hong Kong, cerca de 2400€ na minha casa, não pago transporte porque meu amigo compra Power bank para esta empresa a cada dois meses e coloca em seu contêiner de HK para Málaga e me envia para Madri, espero cerca de dois meses para chegar em minha casa, View attachment 1761View attachment 1762View attachment 1763são as LEV50N originais, o mesmo modelo do I-miev depois de 2013, são baterias usadas em torno de 37-40Ah, medem da tensão mínima à máxima em 6 A de corrente de carga/descarga, 1,3 mOhm a 1,6 mOhm. Estou equilibrando e testando agora todo o grupo e espero colocar na minha mochila em torno de 20 dias se o clima melhorar. Coloquei aqui o resultado do meu teste. Não sei a empresa fornecedora, são desmontadores de armazenamento, não são fabricantes como você pode ver no Alibaba ou AliExpress. Tenho cerca de 12.000 peças. Se meus testes e resultados estiverem corretos, meu amigo me disse que poderíamos importar em grandes quantidades para melhorar o preço (e os lucros). Acho que um bom objetivo seria 2.000€ em qualquer destino da UE. Preço mais alto é realmente estúpido, considerando que a opção CATL 93 está disponível.
João

Juanjo MADRI ..

Muito bom..
Quando vai instalar em seu MIEV?.
Depois me fale qual autonomia vai conseguir..

Obrigado .. Adalberon

 

[Volt Energia]

Pergunte a seu amigo quanto fica para mandar um conjunto para o Brasil ..

 

[Juanjo Madrid]

Juanjo MADRI ..

Muito bom..
Quando vai instalar em seu MIEV?.
Depois me fale qual autonomia vai conseguir..

Obrigado .. Adalberon

I hope to do it in less than 20 days, but I work outdoors, the temperature in Madrid is now too uncomfortable, I hope for a sunny day and work for a day or a full weekend, I am not as brave as my colleagues from the north who work with snow around.

Pergunte a seu amigo quanto fica para mandar um conjunto para o Brasil ..

His intention is to wait for my results to make a purchase of 1000 pieces to improve the price. It is easy for him to bring it to Europe, because he does it regularly with his containers and many times they come with enough free space so he does not have It is extra expensive to bring it to Spain, I would add sets of 93 cells (150kg) when I have space, I only pay for transportation to Hong Kong from some region of China. From what I know, the transportation of Lithium is complicated, due to the need for documents that are not possible in cells that are not new, certain certificates cannot be issued by Yuasa when dealing with reused material, according to my friend it is a risk to mix these cells With anything, it is important that they are all in an adequate % charge and tested phissicaly for safe transportation. I wouldn't have dared to do it without him, he speaks Chinese and regularly visits his suppliers.

 

[Juanjo Madrid]

The quality of the packaging in the boxes, cardboard, polystyrene, separators of an insulating material in sheets similar to mica, in my opinion is not high, it seems to be packaged somewhat by hand, cutting each piece with a knife and making packages of 10 cells in each box, It is not what I received when I bought new lifepo cells.
In the last photo you can see the distribution that I have obtained by classifying by internal resistance, clearly a typical statistical Gaussian bell, the internal resistance is accompanied by the load voltage, less tension, less resistance, my range is 1.14 milliOhm at 1.58 milliOhm, measuring fast. Now I am balancing by grouping the lowest voltage with the highest, I hope to have balance in all of them in two weeks on 3V88. I don't know if it is appropriate to balance 90 cells in parallel all linked together, does anyone know if there is a maximum appropriate number? I am taking electrical precautions by using 0.25 mm wire in the joints, I do not use busbar, I think the thin connection wire would act as a fuse in the event of a cell problem.

 

[MickeyS70]

The number of cells you can put in parallel is purely limited by the space you have.
To avoid high equalisation currents put a resistor between cells with high voltage difference..

 

[Juanjo Madrid]

I finally finished replacing all the cells with the LEV50N model and reinstalled the battery pack. In initial tests, these cells seem to be more resistant and the problem of power limitation during strong acceleration or long climbs no longer appears, I am happy.
The autonomy has not yet been recalculated, after 6 charging cycles, it increases slightly with each charge reaching 78km in use. The cells charge fairly evenly, going from stopping charging with 4V075 up to 4V105.

However, during discharge, there is an imbalance of up to 0.3 V. When there are only two bars left on the battery indicator, one cell in particular, cell H in bank 2, begins to diverge more quickly from the rest, the turtle appears when reaching 2.80 V while the others remain around 3.5 V, and the closest to the bottom is one at 3.22 V at this point there are 8km of RR left.

Before installation I grouped the cells based on internal resistance and bank 2 are the ones with the highest internal resistance (around 1.4-1.5 mOhm each, 12,9 mOhm the full 8 cells 2 pack). It seems like this bank heats up faster than the others. I've read 36 degrees while the rest were around 30 degrees.

In previous attempts I found that after replacing one bad cell, others started failing shortly after the first was replaced.
Does anyone think it would be reasonable to put in a CAN bus interceptor and try to momentarily suppress the low voltage cell by cloning the value of another cell in real time? That way I would not only replace this one but any others that might fail behind it.

As you can imagine I want to make sure that the next time I remove and reinstall the battery pack it is the last time. Any advice?

My next step is BMU replace with LEV50N, I buy a cheap 14,5Kwh BMU (80 cells) and my pack is 88, I can change directly? Some precaution before I can do?

Lev50N pack


IR in each pack

Temperature in full discharge (2 bars)


Temp/Volts in full discharge (2 bars)


Volts/Temp on charge

 

[Volt Energia]

João ..
Parabéns .
Fico feliz que está dando certo a troca das baterias ..
No Brasil tive grande dificuldade em fazer esse procedimento pois existe apenas 6 MIEV no país . Certamente não temos profissionais com sua capacidade e conhecedor de MIEV igual a você por aqui

Seria interessante importar eu já importar as baterias já montadas no suporte e todo conjunto testado ..

Então retire o do meu MIEV e instale o Outro ..

O que você orienta .

Obrigado Adalberon

 

[MickeyS70]

I finally finished replacing all the cells with the LEV50N model and reinstalled the battery pack. In initial tests, these cells seem to be more resistant and the problem of power limitation during strong acceleration or long climbs no longer appears, I am happy.

Congratulations, well done

The autonomy has not yet been recalculated, after 6 charging cycles, it increases slightly with each charge reaching 78km in use. The cells charge fairly evenly, going from stopping charging with 4V075 up to 4V105.

It will take time as the BMU only allows capapcity changes of about 2Ah/month

Before installation I grouped the cells based on internal resistance and bank 2 are the ones with the highest internal resistance (around 1.4-1.5 mOhm each, 12,9 mOhm the full 8 cells 2 pack). It seems like this bank heats up faster than the others. I've read 36 degrees while the rest were around 30 degrees.

Makes sense, high internal resistance leads to higher temperature

Does anyone think it would be reasonable to put in a CAN bus interceptor and try to momentarily suppress the low voltage cell by cloning the value of another cell in real time?

No, a CAN bridge can only be used safely, if the reported cell value is incorrect, but the cell voltage itself is 'good'.

My next step is BMU replace with LEV50N, I buy a cheap 14,5Kwh BMU (80 cells) and my pack is 88, I can change directly? Some precaution before I can do?

The BMU needs to match the number of cells installed...

 

[Juanjo Madrid]

Então retire o do meu MIEV e instale o Outro ..

I will answer you in English for the rest of the group.

The cell to cell change is not very complicated but the LEV50 and LEV50N cells are not physically exact, you need to physically adapt the box to the new cell, in my case the CMU were not perfectly at the appropriate height, I tried various solutions but I did not achieve a perfect fit, raising the cell is not enough because the terminal height is different, the result is that the CMU remains slightly sunken and the floating PCBs remain below the main PCB.

It is always easier to change the complete set but also more expensive, at least in my market I would have had to pay double.

Keep in mind that as MickeyS70 says, then you have to leave a lot of time until the capacity is reprogrammed, so ideally you have to do battery maintenance that makes the process a complete discharge and charge, for this you must have the DiagBox software and Lexia OBD adapter. Furthermore, the chemistry of LEV50N and LEV50 does not seem to be exact, so I must change the BMU if I want to do things right. I don't know what implications not doing so will have, but I think the small cost of the BMU is worth changing.

I think that in your case it may be easier to get CATL93, VOLT 93, or similar cells locally and proceed to change the cells, after CNC work on the Busbar that you can surely do in your country, this is important to do well for the temperature capture through the bus.

 

[Juanjo Madrid]

No, a CAN bridge can only be used safely, if the reported cell value is incorrect, but the cell voltage itself is 'good'.

The idea was to use it temporarily to remove the next problematic cell if it exists, perhaps add 0.2V to the problematic one to reduce its indication but make it proportional, since the next one does not appear now because cell H of group 2 means that the vehicle with about 55Km traveled does not circulate anymore, I think you are telling me that it is not possible because of your fear that this cell will go into overdischarge and be destroyed or worse still catch fire, so: is the temperature a good indicator about the state of the most damaged cells?


My friend from Hong Kong has requested a quote for cells filtered by internal resistance, we want to see if they can send us guaranteed cells with IR below 1 MilliOhm, it is expected that the used cells will be in a variable state and perhaps it is a dead end to use them as a traction battery for an electric vehicle with high current demands, where the internal resistance is decisive, they may only be used as a solar battery or UPS with demand currents over 30 or 50 A for each.

I'm already thinking about how to use the LEV50 batteries as support for these LEV50N but I don't like carrying another 100Kg of cells in the back of my cabin to get 360V and inject with a DC/DC converter

 

[Volt Energia]

What do you think about buying the cells and coming here to Brazil to exchange them?

I can set up a group here and you can do it in other MIEVsss..

My friends who have TESLAs here do it this way. There is a group and the professional comes from Mexico and does maintenance on several TESLAs.

 

[tomhanman]

I'm no expert on this car. But I did part out lev50n cells from a couple of cars. When I was testing their capacities at 20A car A was getting 40-41Ah and car B 45-46Ah. Their internal résistances were 0.2-0.25 and 0.5-0.7 mOhms per cell respectively.

Not really enough data points for a trend, but it might suggest that your lev50n are quite well used and likely to keep failing now that they have started.

On the other hand I believe the measurement of IR is somewhat variable depending on method and charge level so it is possible that comparing my values to yours is not valid.

Well done on the work though, that's a lot of manipulation to avoid accidents