# Kia Niro batteries



## CanadaLT28 (Oct 15, 2011)

I don't see much discussion about using Niro batteries in conversions. Any reason why not to?. I don't see many truly negative comments about the battery other than the odd fire.


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## brian_ (Feb 7, 2017)

There just are not many Niro EVs out there in the salvage stream yet, because the Niro EV only started in 2018... and of course it's unlikely that anyone has figured out the factory BMS yet.

Some EV components are apparently shared with the Hyundai Kona, and the battery is likely the same (or at least the same modules) as the latest Kia Soul EV... or maybe not, if the Soul gets the Kona battery. There are apparently two capacities - 39.2 kWh and 64 kWh. tiger82 used the earlier Kia Soul EV battery in the Tesla Powered Cobra Race Car, where it apparently worked well but just didn't have enough capacity (it was only 27 kWh, versus the current 64 kWh). The original Kia batteries were air-cooled, but the current Kia /Hyundai packs are liquid-cooled.

The Niro battery is reportedly a polymer-electrolyte design from SKI, different from the LG Chem battery in the Kona. The fires were apparently in vehicles with the LG Chem battery.

LG Chem and SK Innovations are apparently in a legal fight over intellectual property rights, LG accusing SKI of stealing designs.

Other than minimal overall specs from Kia, I haven't seen any details about the Niro EV battery. I don't even know how many modules it is split into.

One entire Niro EV battery might be a good match for the dual Leaf motor truck. The Niro EV's maximum motor power is 150 kW, similar to two original Leaf motors or one Leaf+ motor, and the battery must support that. It weighs (according to Kia) 1,008 pounds.


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## keessie (Jan 1, 2022)

I am looking for somebody how figured out the factory BMS of the Hyundai Kona/ Kia E-niro 64 Kwh battery pack.
Could you help me with info? or show me he way?

thanks.


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## CanadaLT28 (Oct 15, 2011)

Unfortunately (or fortunately), I have gone Model S modules so I will be no help there.


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## remy_martian (Feb 4, 2019)

^^ Hire an engineer for utility-grade energy storage. This is DIY electric CAR


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## Heikki J. (Dec 30, 2020)

I'm also searching for information on these Kia/Hyundai batteries. I recently purchased a Hyundai Kona 64kWh battery pack (got it fairly cheap) and now studying what I could do with it. So far haven't found much information about the BMS.


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## wintersaw (12 mo ago)

Heikki J. said:


> So far haven't found much information about the BMS.


hook up the 64kwh batterypack to CAN?


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## Heikki J. (Dec 30, 2020)

If I could hook up to battery's CAN, that would be great. However, I don't have that expertise. Is there any advice where to start? I have no earlier experience on communicating CAN bus other than watching a few Youtube videos 

I actually ended up disassembling the battery pack to module level. Below are some photos from my experiment. The pack consists of 10 modules which are bundled in five pairs, each having one BMS slave that are then connected to master BMS. The modules are 8*3P10S and 2*3P9S, whole pack being 3P98S. Each cell is 218Wh. If I found these Erni connectors I could build my own wiring loom for some aftermarket BMS and it's also possible to utilize the existing wiring loom. I've measure and it's possible to get almost all (but not all) cell voltages from the pins of the connector.






















































Master BMS, cooling liquid hoses, contactors etc.



























In the rear end of the battery pack modules are stacked on top of each other.









Service disconnect and a fuse are located on the top of the rear end of the battery pack.


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## Heikki J. (Dec 30, 2020)

Each 3P10S module was 38.4 volts so these are well charged over 50%.


















There's a fuse built in one of the bus cables.









Two modules are connected with a "jumper" component. In overall lots of M5 bolts are used to build these modules. It would be easy to connect to these modules because of the bolt connection.









One of the modules moved to a pallet. These are pretty heavy, bout 80 kg.









Each pair of modules are attached to a cooling/warming plate with a double-side thermally conductive adhesive.


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## Heikki J. (Dec 30, 2020)

I did disassemble one of the 3p9s modules. They could easily be used in some application as individual 3p 650Wh cells. Six M5 bolts in both ends.


























The modules have two PCBs connecting the cells to a connector where the voltages are going to slave BMS modules. There does not seem to be any chips in these boards, just connections to a connector.









There are total of six different connectors. These blue ones are in 3p9s modules, 3p10s modules have red and blue ones. Connectors are made by Erni. So far I haven't found exact types.




































Two modules are always linked to each other so it's possible to measure voltage of both modules in one connector.


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## wintersaw (12 mo ago)

this teardown was great! 
red/blue 20pins connector is balancing (i guess)
blue 10pin are temp sensors (i guess)
black 20pin are connector to master or slave bms (i guess)

I have little experience with canbus, short said.. raw and might be encrypted for data validation. The conclusion is the OEM-master/slave bms might be encrypted with the key stored in car-data. If you dont got your hands on that then those bms might be useless..


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## wintersaw (12 mo ago)

whats the size of the module? lengh*width*height in cm?


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## Heikki J. (Dec 30, 2020)

The connectors are all for balancing. It's a bit difficult to explain the connections. Temp sensors are saparate from these, they are connected straight to the slave BMS. There's only total of four temp sensors in these 10 modules plus one on cooling circuit. So only four modules out of 10 has one temp sensor!
The blue, red and black connectors are only for cell voltage/balancing. Smaller 3p9s -modules only have the blue connectors since they are only connected to the next module on one end. 10s modules have connectors on both ends so it's possible to connect next module on either end and still handle balacing for two modules at the same time from either end of the module pair.


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## Heikki J. (Dec 30, 2020)

Here's a photo of the temp sensor.








Here's an example of a wiring loom that connects one slave module to one pair of modules. Blue connectors are going to one end of the module and the BMS can see both modules - they are linked with the bridge cable (there was picture earlier).


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## remy_martian (Feb 4, 2019)

I'm digging that temp sensor. 

No other markings to ID it?


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## Heikki J. (Dec 30, 2020)

No, unfortunately there is no other markings on the temp sensor. 








Here's another view on the temp sensor. There are these slots on modules (six on each) where the temp sensor can be inserted. Plenty of options but total of only four of these sensors in the whole pack is used.









Each cell pack have four slots (two on each end) for these sensors.









Here's the whole harness on my garage floor. I've removed some of the module harnesses (orange ones) and only one of the temp sensors is attached. The communication to the battery is via connector at the bottom.

























Here are the coctactors, pre-charge resistor, connection to inverter. Battery + and - are connected under the black nuts on top of the device.


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## Heikki J. (Dec 30, 2020)

Here's the inside of the master BMS. No any markings on the ICs.


















And here's slaves, with and without casing. The one on right has the battery module harness connected.

















It would be great to have a circuit diagram of whole battery but unfortenately I don't have that.


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## wintersaw (12 mo ago)

been searching but didnt find any fitting the sockets, however, b01-s seems similar(32pin) and yours at 33pin..





Kia Niro : BMS ECU Schematic diagrams : High Voltage Battery Control System







www.kniro.net


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## wintersaw (12 mo ago)

found the 33pin connector.
"
Automotive Connectors > Wire To Wire Connector
*C025060 WP 33M ASSY*
Part Number :MG646089-5Series :HYBRID SERIES
"


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## Heikki J. (Dec 30, 2020)

I believe I could still get the female part of the connector from the donor car where the battery came from. If needed.


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## Heikki J. (Dec 30, 2020)

Connector of BMS slave 36pin + 28 pin










BMS master left side 20pin + 16pin









BMS master right side 24pin + 20pin

They look a lot like ones on that kniro.net link but pin counts won't match. Also the connector pinout on the tables seem to be for a smaller size battery since this has ten modules instead eight and 98 cells instead of 64.


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## brian_ (Feb 7, 2017)

Heikki J. said:


> I did disassemble one of the 3p9s modules. They could easily be used in some application as individual 3p 650Wh cells. Six M5 bolts in both ends.
> View attachment 127215
> 
> 
> ...


It looks like the cell tabs are welded to connector plates on the negative ends and to some sort of threaded inserts (one per cell) on the positive end, with the M5 bolts tying those plates and inserts together. Is that right?


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## Heikki J. (Dec 30, 2020)

There are similar laser-welded connector plates on both ends - on the other end it's on the top side, on the other end bottom side.


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## brian_ (Feb 7, 2017)

Heikki J. said:


> There are similar laser-welded connector plates on both ends - on the other end it's on the top side, on the other end bottom side.
> 
> View attachment 127405


That makes sense - the plates for the positive end (on the bottom side of the module, not even the same flange of the cell housing) are just not visible in most views. Thanks! 

It appears that this unusual configuration leads to the need for the parts shown laying on top of the module in this image from post #10:


Heikki J. said:


> View attachment 127217


... which diagonally connect the positive of one cell group (at the bottom of the module) to the negative of the next group (at the top of the module). One of these is needed on each side of the module to make all of the connections. It seems like an excessive amount of interconnecting conductor, but they must have had some reason.


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## z0rglub (11 mo ago)

Hello folks,

If I may add to this thread. I have a 64kWh battery I am trying to speak to (CAN), before going any further. I did some work on the wiring diagram for the 33-pin connector, shared below:

google sheet - kia 33-pin wiring

So far, I am unable to have the Battery to even be powered on. I have no amperes drawn for wires 1 and 2 (+12V) , and wonder what I should be doing with the SRS crash signal (pin 13). I did try GND and 12V without success.

I am also wondering if shunting the interlock of the big HV cable is the right action, or should I instead ground them (based on the picture below):


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## remy_martian (Feb 4, 2019)

Activating the SRS crash signal may have opened a pyro fuse in the unit, if there is one in there. Could also immobilize the controller in firmware needing a reflash.

I'm not certain of either of these, but they're the only reasons I can see for having the crash signal as an input...to immobilize and safe the vehicle after a crash. You may have immobilized a good unit if the airbags didn't go off before...

"may have"


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## z0rglub (11 mo ago)

well, the car was definitely and properly crashed before, I have received the pictures. I don't think I have done any worse than what it actually is. everything went through current sensor, and yep, I got zero mA.
very little documentation on the SRS controllers and the signals they send.
thanks for your inputs remy_martian


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## wintersaw (12 mo ago)

theres a fuse in the battery-pack, 15A rating. Maybe Heikki can check if black/white(13) it goes to a fuse or a selenoid or somewhere else? Depending on that we might can tell if it should be wired high or low...

the SRSCM is mounted in the car, that wouldnt trigger the batterypack to go and kill it self during a crash....? my guess is that black/white(13) is output for srscm.. but maybe SRSCM does what you telling us, however i thought the BMS did all the triggering for the internal fuse to blow...


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## z0rglub (11 mo ago)

Hi wintersaw, thanks for your inputs! From the document I have, the SRS signal is called crash output indeed, so the battery pack must be at the receiving end.









the wire is then eventually changing to brown and connects to the BMU










But it does not help me from a pure wiring perspective to know what I should be doing with it.

In relation to the interlock of the big EV cable, I found further details, and my interpretation is the interlock is only for each side of the connector, not from 1 connector to the other. Shunting it or not does not make any difference to the battery, but to the HV junction block. (which I do not use).










---
Coming back to the fact I do not have any power drawn from the BMU, another aspect is the presence of a ground connection point for pins 11 and 12 of the BMS (as seen on my 2nd diagram). which seems an internal to the battery pack ground which eventually ends up on pin 33 of the connector.









So... all that to come back to my biggest unknown being this SRS signal. (sorry for the braindump).


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## wintersaw (12 mo ago)

hm..well.. for that you need to probe the signal from SRSCM to know..

well, that documentation did hurt my brain. 😉 I usally work with ansi/ieee standard, i have no idea how to read this... Its like paint for me But hey! its something!

your documentation, is it possible to export the whole schematic to a complete dwg instead of chapters?

Inside the BMS, (or is it called BMU?) those gray dots looks like resettable fuses to ground. That might help your BMU to start...?


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## z0rglub (11 mo ago)

I think I should have mentionned the 33-pin connector is call EB11 on the wiring documentation...

From a pure lexical point of view, the gen2 Kias have a BMS composed of a BMU and slave CMUs.
I unfortunately have only exported PDFs when I purchased 72h of access to Kia documentation. I did not took the time to crawl the site and download it, so I cannot export to DWG I am afraid. I did it quick and dirty print to PDF. 

Below an example of a CMU










I am also attaching a training from KIA on their EV technology, quite useful to me for trying to understand the big building blocks.

Lastly, I did not open my battery pack yet, and was hoping not having the need to, but it looks like I will need to if I want to move forward... many thanks for your inputs!

now, I love to have someone plugging an oscilloscope on the SRS pin 13 of EB11 
Also, the PRA documentation mentions a 15A "EV fuse"... this one could be dead as well?


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## Bisimoto (Aug 12, 2020)

Heikki J. said:


> I'm also searching for information on these Kia/Hyundai batteries. I recently purchased a Hyundai Kona 64kWh battery pack (got it fairly cheap) and now studying what I could do with it. So far haven't found much information about the BMS.


Do you still have a good source for these? I would love to play with one.


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## bashers22 (9 mo ago)

I'd suggest speaking to the guys at SimpBMS.
They've a BMS unit that can be used with Tesla, BMW i3, VW golf and other car batteries.
They may be interested in probing this unit further and adapting to it
I'm using it for my i3 battery project, and the team are fast and agile


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## Heikki J. (Dec 30, 2020)

Bisimoto said:


> Do you still have a good source for these? I would love to play with one.


You mean whole battery pack or just the BMS? I don't have a source where I could get a complete pack when I want. Finland is a small market and totaled EVs still not very common. I still have the cells/modules from this pack but sold the BMS+wiring to z0rglub for further analysis.



bashers22 said:


> I'd suggest speaking to the guys at SimpBMS.
> They've a BMS unit that can be used with Tesla, BMW i3, VW golf and other car batteries.


That would be really great! Kona/Niro is anyway pretty common and I'd assume these packs will be pretty common also after a few years. I'll send them an email and see if there's any interest.


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## z0rglub (11 mo ago)

Hello everyone,

I just wanted to confirm I am not dead  I have had zero time to look at the BMS, but I do not despair finding time to work on it. I have indeed Heikki's battery electronics home.


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## Swing (Apr 25, 2021)

Great teardown! Are there any weight and dimensions of the cells?


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## Matrixxed (5 mo ago)

This is a very cool Tear down. Thanks for the great and detailed photos. Would you be able to make a photo of the plastic frame of the cell housing in more detail and the detail how each cell is welded to the connector? I have to reengineer for an electric motorbike these frames and 3d print them as I can not use exactly the Kia units. Are they closed on one side? Is there a metal folded heatsink Integrated on one side to touch the watercooled plates?








It would be great to see even more details.


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## Raz31337 (5 mo ago)

Swing said:


> Great teardown! Are there any weight and dimensions of the cells?


I have two of the 10s Kia Niro cells, do you still need measurements and weight?


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## z0rglub (11 mo ago)

A small update (although still not successful).
I found documentation on the SRS Crash output signal









So, the wire must be at 5V. Only when a crash occurs the SRS will ground the signal for 200ms.

Unfortunately this is not enough


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## adloveridge (2 mo ago)

Can I ask (before I purchase), is it feasable to split those 10s battery packs to construct a 14s battery (obviously with 3rd party BMS)? Thanks.


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## Heikki J. (Dec 30, 2020)

adloveridge said:


> Can I ask (before I purchase), is it feasable to split those 10s battery packs to construct a 14s battery (obviously with 3rd party BMS)? Thanks.


Hi! I don't think it's feasible. The modules are in metal frame and when you remove the frame it's very difficult to compress the cells back to some kind of frame. Is the frame needed - I don't know. You could easily build a 14S pack from these but you'd need to do some kind of custom frame for the pack.


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## adloveridge (2 mo ago)

Thankyou for the advice. One other query I have with these cell packs is there orientation. Obviously in their normal environment the 10s module packs are flat. Do you know if these types of battery packs can be orientated differently without any risk or detrement? If the module pack was stood on its smallest side for instance, does gravity have an affect on performance or safety due to extra weight of compression?


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## Heikki J. (Dec 30, 2020)

I can't say 100% sure but I don't think orientation matters.


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## Heikki J. (Dec 30, 2020)

For those interested, I made for myself a simple wiring diagram for the dual module (20S3P) configuration based on the original Kona wiring harness. This is for connecting some aftermarket BMS to the module. The connector is the one going to the slave BMS. Not sure if this is readable but I have a PDF version also. I don't have access to any fancy SW for making wiring diagrams so I used Google Sheets 

If anyone has any clue if the mating connector is available somewhere, let me know. otherwise need to cut the wires and use some other connector. The wires most likely need to be extended anyway.









Kona akkumoduulit


Cell layout Hyundai Kona 64kWh battery module wiring 20S3P 13kWh dual module configuration Black Brown Red Orange Yellow Green,NC Green,NC Black Blue Purple Grey White Black,NC Black,NC Black,Brown,Red,Orange,Yellow,Green,Black,Blue,Purple,Grey,White,Black,White,Grey,Purple Module 2 +,Cell grou...




docs.google.com


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