SHENZHEN FACTORY TECHNOLOGY battery packs- is it real?

[NeguE]

Thank you for sharing this info

 

[noelho]

You need to tweak so many lookup tables with offsets, voltage limits, degradation data, internal resistance calculations, power reduction tables, temperature maps, charging maps, fastcharging maps, etc. It's not even funny how dangerous it will be long term to use the wrong parameters here.

Is it possible to flash parameters of a 62kWh BMS into a 24kWh BMS? IE: Is there a hardware difference between the BMS or is it purely parameters difference?

Thankfully Safetyuggs is working on an open source version of this flashing, this Vivne stuff is scary to watch!

Oh, that would be cool!

 

[Dala]

Is it possible to flash parameters of a 62kWh BMS into a 24kWh BMS? IE: Is there a hardware difference between the BMS or is it purely parameters difference?

The 62kWh BMS is a dual chip BMS, so its firmware cannot be flashed on a 24kWh BMS. Not that it matters, since the Nissan 62kWh Chemistry is NOT the same as the CATL cells that these Chinese manufacturers are putting in. So you need to build your own firmware with the correct settings for your cells.

 

[almacd64]

Wow that video was garbage! They are using the Russian closed source program for flashing the BMS, and they do not show any parameters what has actually been changed. It is NOT as simple as making 24kWh into a 50kWh battery.

You need to tweak so many lookup tables with offsets, voltage limits, degradation data, internal resistance calculations, power reduction tables, temperature maps, charging maps, fastcharging maps, etc. It's not even funny how dangerous it will be long term to use the wrong parameters here.

Thankfully Safetyuggs is working on an open source version of this flashing, this Vivne stuff is scary to watch!

Generally they don't show you everything they do in those videos, a lot of stuff they quietly gloss over as proprietary. But their whole philosophy is to change the absolute minimum between the oroginal battery hardware and chemistry and the new to avoid issues. The new bms that arrived with my kit has "ROM: 50kwh e-nv200 (cooling) " printed on it. Which suggests they've flashed more than a couple of values. I'm quite sure they're keeping an eye on all open source bms activity for other ways of approaching the problem. Their other philosophy does appear to be one of continuous hard ware and software improvement.

 

[Dala]

Generally they don't show you everything they do in those videos, a lot of stuff they quietly gloss over as proprietary. But their whole philosophy is to change the absolute minimum between the oroginal battery hardware and chemistry and the new to avoid issues. The new bms that arrived with my kit has "ROM: 50kwh e-nv200 (cooling) " printed on it. Which suggests they've flashed more than a couple of values. I'm quite sure they're keeping an eye on all open source bms activity for other ways of approaching the problem. Their other philosophy does appear to be one of continuous hard ware and software improvement.

If it is "proprietary", then it is impossible to call this product safe. If they change the absolute minimum, it wont be enough to handle the cells as they age. The only way to confirm this BMS solution as safe, is to have it transparent and peer-reviewed, which is impossible with the current solution they have.

Let's hope they can make the switch to the open-source solution soon, and share their findings. Before that I would strongly advice against this battery solution.

 

[DaveinOlyWA]

From what we know, they flash the new battery size into the BMS. and those are the only values they change. No need for any CAN bridge and the BMS logic for balancing battery is untouched.


There is supposed to be some kind of pairing process using LeafSpy, but thats about it.

Ok so this isn't DIY? They do the install and SW programing?

 

[noelho]

Ok so this isn't DIY? They do the install and SW programing?

Yeah, its a closed source BMS solution by VIVNE.

@safetyuggs is working on an open source solution. Their progress is pretty amazing:
https://mynissanleaf.com/threads/reverse-engineering-bms-firmware-reflashing-bms.36627/

 

[Ryan]

Wow that video was garbage! They are using the Russian closed source program for flashing the BMS, and they do not show any parameters what has actually been changed. It is NOT as simple as making 24kWh into a 50kWh battery.

You need to tweak so many lookup tables with offsets, voltage limits, degradation data, internal resistance calculations, power reduction tables, temperature maps, charging maps, fastcharging maps, etc. It's not even funny how dangerous it will be long term to use the wrong parameters here.

Thankfully Safetyuggs is working on an open source version of this flashing, this Vivne stuff is scary to watch!

I sense strong “prejudice” from this. I myself drove with vivne 50kwh battery for half a year already. I got from them the whole pack and they told me the reprogrammed BMS had already been installed in the pack before shipping. The result is the new battery just working like original, seamlessly pairs with my vehicle. The mileages from the new battery were very accurate on my dash. Smooth using my car now. I’m still alive by the way How “dangerous” as you said could be? I think they’re just not obliged to show all the details in the video. Of course, it is a big guy of you to work on an open source version. Seems still need a long time and require verification. For the Leaf owners as myself whose batteries already "died", their battery pack is a lifesaver indeed.

 

[cornbinder89]

I respect Dala's knowledge, experience and expertise, that he willingly shares for free here. One persons 6 month experience doesn't negate his concerns, after all would you buy a car that couldn't make it beyond 6 months? The question is more long term.
I understand you were willing to accept the risks, and are happy with the results, at least so far.
We have also learned on this site, of someone who got a new pack from China (not sure of the seller) that had one bad or low module from the get go, So one happy, not happy.
Dala isn't saying that with or without the modified BMS that the the pack will not recharge and work, he is saying that unless the BMS is modified to match the cells there is no way to know how safe it is. A company can say what they like, but the proof is in the willingness to stand behind the battery or release the spec's for the modified BMS.
The potential problem is a thermal-run-away fire, total loss of the vehicle and anything else close by. If that happen with a replacement battery Nissan will wash their hand of any responsibility, what are the chances your battery provider will accept any responsibility? I'd say less than none.
When it comes to re-programing a BMS, I knowth what I knowth not! I can recognize those who do know what is involved and respect their concerns. I doesn't mean VIVNE doesn't know how to re-program, but without the proof (source code) you just have their word, and stuff out of China has a very mixed reputation in that regard.

 

[leafy greens]

I respect Dala's knowledge, experience and expertise, that he willingly shares for free here. One persons 6 month experience doesn't negate his concerns, after all would you buy a car that couldn't make it beyond 6 months? The question is more long term.
I understand you were willing to accept the risks, and are happy with the results, at least so far.
We have also learned on this site, of someone who got a new pack from China (not sure of the seller) that had one bad or low module from the get go, So one happy, not happy.
Dala isn't saying that with or without the modified BMS that the the pack will not recharge and work, he is saying that unless the BMS is modified to match the cells there is no way to know how safe it is. A company can say what they like, but the proof is in the willingness to stand behind the battery or release the spec's for the modified BMS.
The potential problem is a thermal-run-away fire, total loss of the vehicle and anything else close by. If that happen with a replacement battery Nissan will wash their hand of any responsibility, what are the chances your battery provider will accept any responsibility? I'd say less than none.
When it comes to re-programing a BMS, I knowth what I knowth not! I can recognize those who do know what is involved and respect their concerns. I doesn't mean VIVNE doesn't know how to re-program, but without the proof (source code) you just have their word, and stuff out of China has a very mixed reputation in that regard.

Well said

 

[DaveinOlyWA]

I sense strong “prejudice” from this. I myself drove with vivne 50kwh battery for half a year already. I got from them the whole pack and they told me the reprogrammed BMS had already been installed in the pack before shipping. The result is the new battery just working like original, seamlessly pairs with my vehicle. The mileages from the new battery were very accurate on my dash. Smooth using my car now. I’m still alive by the way How “dangerous” as you said could be? I think they’re just not obliged to show all the details in the video. Of course, it is a big guy of you to work on an open source version. Seems still need a long time and require verification. For the Leaf owners as myself whose batteries already "died", their battery pack is a lifesaver indeed.

What was the cost of your pack and where are you located?

 

[lley]

Yaste Tech is more cost-effective and professional!! www.yastetech.com

 

[Dala]

REDACTED COMPANY limits the kW output of the product without informing about it. It is limited to prevent cell damage, since the replacement cells cannot withstand the full 80kW of the LEAF.

First test drive on the new firmware after removing the REDACTED COMPANY. First thing I noticed is the increased acceleration. By a noticable amount. I wonder why the REDACTED COMPANY bridge limits available KW? With REDACTED COMPANY it'll jump up to 80kw but will quickly fall to around 60kw, not the case with the bridge removed.

This is also why many of these replacement packs are an extremely bad idea with a ZE1 vehicle, that would go to 125kW/180kW peak.

 

[FrancoVecchi]

I sense strong “prejudice” from this. I myself drove with vivne 50kwh battery for half a year already. I got from them the whole pack and they told me the reprogrammed BMS had already been installed in the pack before shipping. The result is the new battery just working like original, seamlessly pairs with my vehicle. The mileages from the new battery were very accurate on my dash. Smooth using my car now. I’m still alive by the way How “dangerous” as you said could be? I think they’re just not obliged to show all the details in the video. Of course, it is a big guy of you to work on an open source version. Seems still need a long time and require verification. For the Leaf owners as myself whose batteries already "died", their battery pack is a lifesaver indeed.

Ryan, I'm glad your new battery pack works so well.

But some other people have had problems, and long-term safety is a very important issue: 6 months under normal conditions is not a significant test.
It is necessary to evaluate what happens if borderline conditions arise, such as accidents or overheating during a DC recharge.
For example, there is currently an official Nissan recall for some batches of batteries manufactured in the United States due to car fires that occurred during DC charging.
It's true that the original battery has issues, but at least it has passed all the approval tests. We know nothing about these, except that they are built in an artisanal way.
Having said that, I am happy for you and grateful to you for helping to experiment with these solutions.

 

[bandapear]

I am an electrical engineer/firmware engineer and have been talking with Vivne for the last 6 months; I am trying to assess their battery Modules. Before buying the whole pack, I asked them if I could purchase one module to test it, like overheating it or putting it in freezing temperatures. I told them I would share any results to fix any issues without going public. They refused in their defense my approach was informal. I have concerns regarding their battery packs for the final QA/QC. I've watched their videos, and their approaches seem hand-wavy. even one user here in the forums is reporting 6m+ of good operations that don't mean anything on scale. I don't want this battery pack ending up with someone in the south and God forbid something happens. I will approach them formally next time and i will open source all my findings in terms of their BMS and their battery pack , until then please don't take the risk. btw I have a 2012 with 26% SOH and i was trying to find a battery pack for it and honestly getting a car from salvage and getting the pack is better (there is some risk ) which i can help you navigate is much cheaper if you sell the other parts. i got a 40kw 100.4 Ahr with 86% SOH for 5k and the other car parts are full operational which i can sell for profit.

 

[cornbinder89]

I am an electrical engineer/firmware engineer and have been talking with Vivne for the last 6 months; I am trying to assess their battery Modules. Before buying the whole pack, I asked them if I could purchase one module to test it, like overheating it or putting it in freezing temperatures.

Not being willing, is a huge red flag. A company that will stand behind their product should be willing to such a request. You weren't asking for a "free sample" which isn't unreasonable in it self. You were willing to pay for one cell/module
If they are truly the mfg, then one module would be no problem. While at the installer level, where they buy complete packs, I could see not having a cell to sell. That would imply they are getting complete "kits" from various sources.
If they want to expand business in other parts of the world they need to prove what they are selling is up to the task

 

[Dala]

One more post before I leave this thread. I have been getting some threats sent to me which is very silly. I simply want people to be able to buy as safe of a product as possible. This is true for any of the upgrade kit manufacturers. If they are unwilling/unable to share the details about how the reflashed BMS / CAN-bridge manages the cells, avoid them.

Example: Here is the Amp allowed map from a 24kWh BMS (explorer232 posted it in the reverse engineering open source flashing thread). Simply using this map with a low kWh CATL pack will cause permanent damage to it. Ask your manufacturer for this map!



The only way to make sure you are getting a good product, is to only buy from a manufacturer that can show precisely how they are controlling their cells.

 

[unBMievable]

I won't name any suppliers, but after installing a few Chinese aftermarket battery packs, yeah quality isn't something they all have in common.
We had a client who actually managed to snap the supplied bus bars due to vibrations caused when driving over our awesome nz gravel road corrugations, causing a harmonic vibration in the bus bar.
Something the Chinese maybe don't have as many of as we do down nz!

 

[EVPowers]

The packs will likely seem fine enough for some period of time.

So far all these companies appear to be drawing from a varying supply of batteries and making them into packs. They are not manufacturing them.

It seems like what is inside the packs may change over time depending on what supply them can draw from.

 

[Dala]

The packs will likely seem fine enough for some period of time.

So far all these companies appear to be drawing from a varying supply of batteries and making them into packs. They are not manufacturing them.

It seems like what is inside the packs may change over time depending on what supply them can draw from.

A working theory was developed by one user that tested the pack from a REDACTED CHINESE SELLER. This is information I am just relaying forward, I have no affiliation with them:

These CATL modules appear to have been salvaged from the EV Taxis in China, from companies there which went bankrupt during COVID.

Massive numbers of cars which were functioning were put out into lots and auctioned off. Those packs are what we are seeing now. These packs were active cooled packs btw.

So, with what we know about these "manufacturers", no testing was done on these packs. So they probably won't reply, not because they want to retain trade secrets, but probably because they don't or didn't know in the first place.