Ohmmu EV6 LFP 12v Battery UPGRADE | Full Installation | Kia EV Forum
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Ohmmu EV6 LFP 12v Battery UPGRADE | Full Installation

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25K views 145 replies 30 participants last post by  Doobiewah  
#1 · (Edited)
Full installation of the Ohmmu LFP 12v battery on my 2022 Kia EV6. Unfortunately the 12v battery on EVs can have problems. Ohmmu offers a direct replacement LFP LiFePO4 12v battery for the EV6 that has many advantages over the factory lead acid batteries. It lasts much longer, is more durable and reliable, has a higher capacity and less voltage sag, is more efficient, and is much lighter. I'm excited to get it installed on my 2022 Kia EV6. I'll also be giving one away very soon, so stay tuned 😃

Anyway check out the video of the info and installation and let me know your thoughts and if you have any questions!


Time for the Ohmmu giveaway! 😀


EDIT: Just wanted to pass along some additional info I got from the manufacturer.

Regarding cold climates, they advised the battery will operate down to -30 celcius, which is -22 fahrenheit. They also stated "In most cases the HV battery of an EV will be at more risk in these situations and have a warming system in the vehicle to address severe cold weather to some extent (which assists in warming the 12V as well), since the HV packs are manufactured with a different lithium chemistry that is more sensitive to extreme cold weather than our LFP batteries (all EVs are recommended to be garaged and plugged in as often as possible in these conditions though)".

Regarding charging, they advised their LiFePO4 batteries are designed to work as drop-in replacements for the 12v SLA batteries they replace and the charging profiles for the two chemistries are closely aligned and work great with their LiFePO4 batteries, which are also covered by a 4 yr warranty if there are any issues.

EDIT: Since I got their new version, I don't have a need for the original one so I figured I'd give it away! 😃


And the Winner! Congrats to Dennis! 😃

 
#15 ·
The Ohmmu may well work but its an expensive "solution" to a rare fault. Consider buying a Power pack jump starter, it would get you going & maybe rescue another driver with a flat battery. I bought a Ring Jump Starter 360 for GBP60, it fits nicely in the front storage of my AWD. I used it to get the small tractor going at Drum Castle gardens where I volunteer.
 
#19 ·
Just wanted to pass along some additional info I got from the manufacturer.

Regarding cold climates, they advised the battery will operate down to -30 celcius, which is -22 fahrenheit. They also stated "In most cases the HV battery of an EV will be at more risk in these situations and have a warming system in the vehicle to address severe cold weather to some extent (which assists in warming the 12V as well), since the HV packs are manufactured with a different lithium chemistry that is more sensitive to extreme cold weather than our LFP batteries (all EVs are recommended to be garaged and plugged in as often as possible in these conditions though)".

Regarding charging, they advised their LiFePO4 batteries are designed to work as drop-in replacements for the 12v SLA batteries they replace and the charging profiles for the two chemistries are closely aligned and work great with their LiFePO4 batteries, which are also covered by a 4 yr warranty if there are any issues.
 
#22 ·
If you go on alibaba.com, you can buy all kinds of dangerous products shipped from China and then foist them on an unsuspecting public or use them yourself and cause your own injuries. And you can make all kinds of unsubstantiated claims and resell the stuff on all the online marketplaces. All I can say is Buyer Beware!
 
#23 · (Edited)
my concerns with this are that it's pretty expensive ($400), LFP has poor performance in very cold temps, and I'm not sure if the BMS and 12v recharging algorithms will be compatible with this battery in all situations. Also, it seems kind of sketchy, like it's someone buying really cheap LFP batteries from china and marking them up significantly. i think it's only a matter of time before sometime gets stranded in cold weather because their LFP replacement battery wouldn't take a charge when it really needed to.

if you are saving weight for a track toy in nice weather, it makes sense. but in a 4400 lb daily driver, its probably a waste of money at best.
 
#24 ·
my concerns with this are that it's pretty expensive ($400)
This exactly. Why fix something if it isn't broken? The Ohmmu replacement battery is a solution in search of a problem. For nearly all of us, the original 12 V battery will be under warranty. You would literally be throwing out $440 that can be better spent.

Sorry but the replacement battery doesn't have any benefits as long as the original is under warranty.
 
#25 ·
Please note that if your car is under warrant, you will jeopardize that warrant. Best insurance is to carry a lithium back up battery, that can be kept in the car and will be kept topped off by the 12v system. If 12v battery malfunctions the reserve battery will enable the 12v systems. Allowing the system to be used. Once the 12v system activates high voltage system will function.
 
#26 ·
Please note that if your car is under warrant, you will jeopardize that warrant.
No this battery won't jeopardize the car's warranty, I was just saying it's a bad financial decision since the original 12 V is covered under the car's warranty (or it has a warranty of its own). This Ohmmu battery is designed as a very expensive drop-in replacement.

You'd be at no more risk for jeopardizing the warranty than if you went to AutoZone to buy a non-OEM lead acid 12 V.
 
#32 ·
LFP/LiFePO4 batteries are amazing! I'm kind of surprised at all the misinformation people think they know but do not about this chemistry. It's FAR more temp tolerant than tertiary formula lithium batteries and for only twice as much as an AGM, will last 3-4x as long and run your car electronics far more efficiently.

Literally, on my last ICE car, the factory audio clearly sounded far better with higher/cleaner voltage and I had way less electrical glitches on a car known for being sensitive to them. After 2 years with 2 full winters using one that has degraded to only 99%, it was funny seeing how much slower my ICE car started when I switched the factory battery back in for trade in, even in 55F weather, I just wish it fit my EV6 :).

Ignorant haters gonna hate, but this is one of the first mods I'm doing with my EV6. Factory batteries from almost all brands are hot garbage right now with a race to the bottom with cost cutting and the peace of mind knowing I'm good is WELL worth it.
 
#33 ·
LFP/LiFePO4 batteries are amazing! I'm kind of surprised at all the misinformation people think they know but do not about this chemistry. It's FAR more temp tolerant than tertiary formula lithium batteries and for only twice as much as an AGM, will last 3-4x as long and run your car electronics far more efficiently.

Literally, on my last ICE car, the factory audio clearly sounded far better with higher/cleaner voltage and I had way less electrical glitches on a car known for being sensitive to them. After 2 years with 2 full winters using one that has degraded to only 99%, it was funny seeing how much slower my ICE car started when I switched the factory battery back in for trade in, even in 55F weather, I just wish it fit my EV6 :).

Ignorant haters gonna hate, but this is one of the first mods I'm doing with my EV6. Factory batteries from almost all brands are hot garbage right now with a race to the bottom with cost cutting and the peace of mind knowing I'm good is WELL worth it.
I was just like you in this regard... ignorant (since you're calling haters "ignorant")... because I saw "LITHIUM" and immediately equated it with the best you can get, as that's what we've been accustomed to in other battery applications in our lives. But the more I researched the issue with replacing the stock battery with an Ohmmu, I realized it was not the right thing to do. Do some more searching on this and you will find out that these batteries are questionable for these cars, as the reported voltages and draws are different than what the system expects. That is a fact. AGM batteries are indistinguishable to the computer in the EV6. I have a LITHIUM (haha) battery starter in my frunk. When the 12v shows any signs of going out (you'll be able to charge it at least one more time with the starter), then I'll replace it with an AGM.

The whole 12v battery debacle had a lot to do with some 22s and some 23s having a bad batch of batteries - I do not believe the ICCU is fully to blame or all EV6s would be stranded by now.
 
#35 ·
@EV- Technician has made a compelling case here against replacing the OEM battery with one that has its own (competing) management system.
Ohmmu 12V battery mentioned in this thread.
This is LFP chemistry with integrated BMS.
It will operate at completely different voltage than 12V AGM battery.
Ohmmu BMS has ability to stop charging or discharging depending on parameters set.
Ohmmu BMS doesn't have lin bus to be integrated into the vehicle network system ( it has to operate as slave BMS to the onboard DC-DC converter ICCU).
Whenever this happens where this aftermarket battery stops charging or discharging, it will cause huge electric noise coming from onboard ICCU ( 12V AGM battery serves also as buffer to eliminate this electric noise).
Electric noise will make many other users on 12V low DC side to stop operating as designed ( because they are not designed for this purpose), it will cause erratic Communication on can bus network ( you can research how can bus traffic is operated).
ICCU has to be coded for this type of chemistry and aftermarket solutions must have BMS that can talk on lin bus to the ICCU from Hyundai. ICCU has to be designed to filter electric noise when aftermarket solutions that can talk to the ICCU is in limp mode and ICCU has to take full responsibility to keep low DC 12V alive. Software engineering has to be adopted for this type of chemistry.
By Default ICCU is designed and set to maintain 12V AGM battery ( it will try to keep this battery at 92% SOC when recharging session is needed, it will use algorithms for charging and maintaining 12V AGM battery ( ICCU is like smart chargers on the market that has multiple different scenarios that will use, how to charge and at what voltage or current conditions).
If you have more questions please feel free to ask. I will be more than happy to answer any questions you may have.
Using LFP or NMC chemistry are strictly prohibited from using on this vehicles or any other ICE powered system with alternator designed and controlled for 12V AGM chemistry.
Ohmmu battery doesn't not have onboard heater assistance for cold weather conditions ( this will trigger Ohmmu BMS to limp mode, if you read between the lines, your EV will be dead without 12V battery running).
It has no heat sinks for fighting against hot weather conditions or when vehicle is operated in stop and go traffic ( where temperatures under hood where air conditioning is running, can exceed limits of LFP chemistry, where Ohmmu BMS will just go to limp mode and cause vehicle to malfunction).
I hope if have read this far you should have basic knowledge of this project and fake advertising that this is full replacement for regular 12V battery without any significant problems or safety issues.
There may be warranty implications as well.
Any LFP chemistry or chemistry that has dedicated BMS are not allowed to be used with onboard ICCU.
 
#37 · (Edited)
"It will operate at completely different voltage than 12V AGM battery."
Now THAT much is def not true, the difference between 12.0v and 12.8. is 100% a non-issue, in fact, most 12v systems run at about 13.8v off the alternator while the car is running anyway... but the rest, especially coding for it, I will certainly look into, so thanks for the info on this!

Edit: More falsehoods -
"Using LFP or NMC chemistry are strictly prohibited from using on this vehicles or any other ICE powered system with alternator designed and controlled for 12V AGM chemistry." I and a LARGE number of people use them on Canbus systems ALL the time with only 100% positive results. That's simply false.

"Ohmmu battery doesn't not have onboard heater assistance for cold weather conditions ( this will trigger Ohmmu BMS to limp mode, if you read between the lines, your EV will be dead without 12V battery running)." - Nonsense, they DO have an internal heater and are so temp tolerant they don't need a heater compared to tertiary and the BMS simply doesn't charge them until they are above freezing and with some heat generated under the hood. It simply runs off the huge aH reserves until the battery is above freezing.

"It has no heat sinks for fighting against hot weather conditions or when vehicle is operated in stop and go traffic ( where temperatures under hood where air conditioning is running, can exceed limits of LFP chemistry, where Ohmmu BMS will just go to limp mode and cause vehicle to malfunction)." Also false, the temp limit on them is quite high and have been tested in very hot conditions with desert off-roaders at underhood temps of 170+ degrees and there is no way there will be THAT much heat under the hood of an EV. But just for additional peace of mind I do wrap them in heat tape before installing too.

Maybe a compelling argument if you blindly believe that nonsense, but that is what it is, nonsense. Anyway, I will look into coding for it at least since there is the ICCU involved here, but that is the only concern out of that spiel that may be valid. With multiple, multiple sites offering these specifically for the EV6 (and a number of them are sold out) and no real complaints out there, I know I have no serious concerns at all.
 
#42 ·
I would be delighted to exchange your opinions vs facts and how onboard ICCU is designed and how dynamic voltage set for lead-acid chemistry is not good for LFP chemistry and just looking at this two examples posted below, let's not even go to the stationary software logic for charging or other parameters that ICCU is constantly receiving from smart sensor attached on negative terminal.
It you have any knowledge of LFP chemistry cells voltage and number of cells to make 12V battery ( it is actually higher voltage than 12.8 for LFP chemistry).
So please feel free to challenge me on this subject. I do need someone like you to provide true facts that are not easy to find this days by searching internet.
I actually work for living on EV vehicles.
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#38 ·
There is considerable insight in that thread, which is well worth reading in its entirety.
LFP chemistry and number of cells they use are far above nominal voltage of AGM battery.
LFP chemistry cells voltage at 3.540V at 95%SOC will be at resting voltage 14.160V
Vs AGM battery resting voltage 12.7.
ICCU will raise voltage over 14- 14.9 when there is desulfation cycle active. This will bring LFP chemistry cells voltage to high and will most likely cause BMS on Ohmmu BMS to stop charging.
Internall resistance that ICCU is checking will be out of calibration values and in winter conditions when shunt temperatures sensor reach calibration values it will trigger 14.9 for extended periods of time that will cause Ohmmu battery to reach voltage per cells dangerously high ( SOH degradation will accelerated).
 
#40 · (Edited)
#43 ·
@danbfree

In the event that you agree to my participation in a professional discussion, and it becomes apparent that my assertions are accurate while yours are not, I would respectfully request that you modify your forum name to "Mr. Nonsense #1" in the presence of all forum members. While I anticipate that there may be others who will attempt to challenge my expertise, you will have the distinction of being the first to initiate this trend.

Perhaps one day we may meet in person and have the opportunity to laugh about and learn from each other.
 
#45 ·
@danbfree

In the event that you agree to my participation in a professional discussion, and it becomes apparent that my assertions are accurate while yours are not, I would respectfully request that you modify your forum name to "Mr. Nonsense #1" in the presence of all forum members. While I anticipate that there may be others who will attempt to challenge my expertise, you will have the distinction of being the first to initiate this trend.

Perhaps one day we may meet in person and have the opportunity to laugh about and learn from each other.
That poster clearly works for Ohmmu so he will never admit any faults with his product. I truly wish we could use a lithium based battery as our 12v battery, as it doesn't make sense that a 21st century high tech car uses 100+ year old technology.