Has anyone replaced their 12V battery with lithium?

[FLKiaEV]

I saw a video on YouTube of a guy who replaced his 12 lead acid accessory battery for his Fiat 500e electric vehicle and he's not had any issues for at least 2 years. I would like to do this too with my 2016 Kia Soul EV+. Does anyone have any experience with this and if so, what battery did they use? The guy in the video used the ReLion RB20 (20ah LiFEPO4) lithium ion battery.

Here's the battery: https://www.ecodirect.com/RELiON-RB20-12-Volt-20AH-Lithium-Battery-p/relion-rb20.htm?gclid=CjwKCAjw95D0BRBFEiwAcO1KDOUQQpAuZ2EV3lerIS_VSIW86QH5PEZfqYRabq_Kl6x1FcFsOS4-XxoCQJ0QAvD_BwE

And here's the YouTube video: https://youtu.be/X_0lFn9YFNg

Is there anything I need to watch out for before doing this? These batteries are supposed to last several times longer than lead acid batteries and have several other advantages too. Any thoughts?

Thanks!
Russell

 

[IanL]

Quote from the Kia Service Manual:

"When replacing the battery, it should be same one (type, capacity and brand) that is originally installed on your vehicle. If a
battery of a different type is replaced, the battery sensor may recognize the battery to be abnormal."

 

[FLKiaEV]

Same brand? That's interesting. The one in there now is from Hyundai's battery division. Might be hard to come by! But anyway, it shouldn't be detected as abnormal because it supplies the same power profile. In fact it's better than the included vehicle battery in pretty much every category (but you wouldn't want to use it in an ICE application because it's not designed for supplying cranking amps for a starter).

I got the battery yesterday. Smaller than I thought it would be, and only weighs about 6 pounds. The battery that's in the vehicle now looks like it's in excellent condition, so I will keep this one on hand just in case. I'm also looking through the warranty book to see if it would void the warranty.

Russell
Kissimmee, FL

 

[MassDeduction]

Same brand? That's interesting. The one in there now is from Hyundai's battery division. Might be hard to come by! But anyway, it shouldn't be detected as abnormal because it supplies the same power profile. In fact it's better than the included vehicle battery in pretty much every category (but you wouldn't want to use it in an ICE application because it's not designed for supplying cranking amps for a starter).

I got the battery yesterday. Smaller than I thought it would be, and only weighs about 6 pounds. The battery that's in the vehicle now looks like it's in excellent condition, so I will keep this one on hand just in case. I'm also looking through the warranty book to see if it would void the warranty.

Never heard of this before. Cool! I bought a used Soul EV, so no warranty concerns on my part, so I might swap it out immediately if it's that much of an improvement! An inability to kill the battery is pretty appealing. I wonder how big the SOC buffers on this thing are? 20%+ each end if we're really lucky.

 

[FLKiaEV]

I ended up with two of them because the first one had a tiny amount of red paste on one of the terminals (no big deal). So, they sent me a new one and said keep the first one! Anyway, this is what the final installation looked like after connecting them in parallel (so that I get twice the amp hours: 40 instead of 20 but still the same voltage):

So far no issues whatsoever, and I like having the peace of mind that it should last several times longer than a lead acid battery. I've tested the setup several times and it always reports around 13.4 V, which is ideal. One by itself would be fine too (unless you leave your headlights on for an extended period of time with the vehicle turned off), but I had it anyways and didn't want to waste it.

If you happen to do this, make sure you connect them in parallel and NOT in series! So, positive to positive and negative to negative will yield a 12V battery with the amp hours of both combined (20 + 20 = 40), which is what you want.

 

[MassDeduction]

They make "LT" (low temperature) variants of this battery. I wonder if that would be a better bet for me? I live in a very mild part of Canada, it rarely drops below freezing even in the middle of winter, but we do on very rare occasions get a winter cold snap that's below freezing. However, ReLiOn only recommends the 75 amp and up versions for electric vehicles, and they only make the LT versions in 20 and 100 amp versions (and the LT 100 amp is an eye-watering $1349!). I suppose I could two LT 20 amp in parallel, as was done by another person in this thread.

What is the ideal Ah for a Kia Soul EV 12V battery? I have access to 2016, 2017, and 2021 models, and am interested in doing this for any/all of them.

 

[FLKiaEV]

Well, I live in Florida so the parallel 20AH setup works well for me (it rarely drops below 30F). I'm the one who did the lithium setup above.

I can't imagine that 75AH would ever be needed unless they're talking about using a series of these batteries to power the vehicle itself, rather than as the accessory battery. After all, the 12V accessory battery that comes with the car is only about 45AH.

I've not had any issues whatsoever so far. If they offer a low temp version and the price is reasonable for a 20AH battery then you might try that. Since the demands on this battery will be quite low, for the most part, even 20AH will be fine 99% of the time. Just don't leave your headlights on for a long time without the main traction battery engaged.

Good luck.

 

[MassDeduction]

Well, I live in Florida so the parallel 20AH setup works well for me (it rarely drops below 30F). I'm the one who did the lithium setup above.

It's been a while since you posted about it. Any additional feedback about your lithium 12v installation? I'm hesitant to make the change unless and until the existing battery is nearing end-of-life, but might jump on board once the existing battery is a little longer in the tooth. Is it still treating you well?

 

[FLKiaEV]

No issues whatsoever. I tested them individually about a month ago and they were still showing excellent voltage (13.something IIRC). I will say that if you are planning on doing this with a parallel setup, do take the time to make sure that the batteries are voltage-matched before connecting them to each other (within a few hundredths of a volt if possible). For example, if you test one at 12.9 volts and the other at 13.3V, I would charge up the first one for a few minutes until it is closer to 13.3V so there are no imbalance issues right from the start (which can cause one to get a little hotter than necessary). Be sure to secure them to each very well and to the battery holder. You might have to get creative here...

And honestly, one 20AH battery will almost certainly be more than enough unless you're in the habit of running your headlights for a long time with the car turned off, or blasting the radio for long periods of time. I lucked out as to how I got the two that I have and was already expecting to use just one, which should be fine for virtually everyone.

 

[MassDeduction]

No issues whatsoever. I tested them individually about a month ago and they were still showing excellent voltage (13.something IIRC). I will say that if you are planning on doing this with a parallel setup, do take the time to make sure that the batteries are voltage-matched before connecting them to each other (within a few hundredths of a volt if possible). For example, if you test one at 12.9 volts and the other at 13.3V, I would charge up the first one for a few minutes until it is closer to 13.3V so there are no imbalance issues right from the start (which can cause one to get a little hotter than necessary). Be sure to secure them to each very well and to the battery holder. You might have to get creative here...

And honestly, one 20AH battery will almost certainly be more than enough unless you're in the habit of running your headlights for a long time with the car turned off, or blasting the radio for long periods of time. I lucked out as to how I got the two that I have and was already expecting to use just one, which should be fine for virtually everyone.

Score! ReLiOn has rolled out a 50 Ah LT (low temperature) battery. It's about twice the price of the 20 Ah LT battery, so more desirable (in a few ways) than a 2x20 Ah set-up. Obviously your 2x20 set-up was better for you as one of them was free!

Interesting that the stock battery is in the 45 Ah range, despite your understanding that even 20 Ah would be satisfactory for most people. I guess they've built in some redundancy that way. The 50 LT is the sweet spot anyway, about double the price of the 20 Ah, but slightly less than half the price of the 100 LT.

How long is the stock 12v likely to last? It's commonly said that 3-5 years is typical for 12v batteries in cars, but the #1 stressor is being used as a starter battery in an ICE car. Perhaps it'll last even longer in an e-car?

 

[ksoul2084]

How long is the stock 12v likely to last? It's commonly said that 3-5 years is typical for 12v batteries in cars, but the #1 stressor is being used as a starter battery in an ICE car. Perhaps it'll last even longer in an e-car?

The main killer of lead acid batteries is draining them below 50% capacity. Of course, in an ICE car cold weather starts are one common way of doing just that.

My understanding is that in EV's the main killer of the 12v is vampire drain on the battery while the car sits unused for an extended period of time, since they don't get charged unless the car is "started" with the main battery-pack engaged.

 

[notfred]

It seems to last 3-5 years, perhaps because of the way it is charged via the DC/DC converter from the main battery versus a gasoline engine alternator. I know one of the early firmware changes was to how the 12V was being charged.

One of the nasty things is that you get no warning of it being about to die. On a gasoline car it would start to crank slowly. On an EV suddenly one time it will not be enough to engage the main battery relay and you go from everything being fine to stranded with no prior indication.

 

[IanL]

I have an inexpensive electronic battery tester. It gives a readout of battery SOH and recommends when the battery should be replaced. It would be a good idea to use it (say) once a month, to forestall sudden death.

 

[FLKiaEV]

Well, I think the reason Kia used that 45AH battery is because it was readily available and so they didn't have to have a specially made one (which would increase cost slightly). Just my guess. But you're right: A typical lead-acid battery for an ICE vehicle gets used up so quickly because of the high demands put on it to turn over the engine, which you can imagine would not be easy especially in high compression engine situations. Plus, I imagine that the high temperature under the hood of an ICE vehicle doesn't do it much good.

Neither of those things are really a factor for an EV because the regular demands on it are low and the temperature under the hood is a fraction of what it is on an ICE vehicle. I'm always amazed at not only how relatively cool it is under my hood but also how CLEAN it is (since the bottom of the engine compartment is closed instead of open to the road, etc).

As for how long the battery that came with it lasts, mine died very shortly after I got the car, less than a week! Luckily I had already ordered the lithium replacement and had it on standby. In general I would think even a lead acid battery would last longer with an EV than with a an ICE vehicle for the reasons mentioned above. Not sure if the stock battery is a deep cycle battery, like the lithium replacement or not though. It's good that the price of these things are starting to come down. Supposedly they have a lifespan of about 10x what a lead acid battery has. That would mean 30 to 50 years, which I doubt, but I still imagine it will be in good shape at 5 or 6 years. I test it (them) every month or so with a multimeter just to make sure it's holding a good charge, etc.

 

[FLKiaEV]

Lithium batteries also do much better at holding a charge when not being used for extended periods of time. Lead acid is not good at this. But you're right that it's good to test them regularly. Lithium holds its charge while being used really well until the very end and then it just dies suddenly. If you have lithium battery-powered tools you've probably noticed that it can be down to only one bar of charge and still be going strong and then suddenly: Nothing. On the other hand, other types of batteries will gradually give less and less power until they die letting you know that they need to be charged or replaced.

IanL, I have a multimeter and I use it about once a month to test the 12V battery combo, but it doesn't give the SOC. Which battery tester do you use? (I do also have SoulEVSpy and the dongle but haven't used it yet and that is supposed to give a ton of info about the traction battery but not sure if it gives info about the 12V).

 

[IanL]

Mine is a Topdon ArtiBattery 101, It is appropriate for lead/acid batteries, but makes no claim as regards Lithium. I only suggested it for people who are still using lead/acid, and want some assurance about its condition.

SoulEV Spy only tells you the voltage of the aux. battery. I guess no other parameters are measured by the car.

 

[FLKiaEV]

Thanks! I'll check into it and see if there are any others that can give the SOC of lithium batteries.

As for the other parameters being measured, this reminds me of something that always annoyed me about car manufacturers: Dummy warning lights that don't even come on until you ALREADY have a fatal or near fatal condition for some part of your car. Like, there apparently are ways to determine if a lead acid battery is getting close to dying (even before we notice, on ICE vehicles, that engaging the starter seemed a bit slower this morning, etc) by reading voltage of the system before, during and after turning over the engine (or putting some other high load on the system). But instead we get a light that comes on WHEN your battery or alternator are pretty much already dead. I thought it would be nice if the vehicle was constantly monitoring everything electrical in the system to see how voltages and amps change over time under the same conditions to give us a "state of health" from green to yellow to orange to red, etc.

Anyway, rant complete. Glad that I (hopefully!) don't have to worry about dummy lights too much anymore.

 

[MassDeduction]

Same brand? That's interesting. The one in there now is from Hyundai's battery division. Might be hard to come by! But anyway, it shouldn't be detected as abnormal because it supplies the same power profile. In fact it's better than the included vehicle battery in pretty much every category (but you wouldn't want to use it in an ICE application because it's not designed for supplying cranking amps for a starter).

I got the battery yesterday. Smaller than I thought it would be, and only weighs about 6 pounds. The battery that's in the vehicle now looks like it's in excellent condition, so I will keep this one on hand just in case. I'm also looking through the warranty book to see if it would void the warranty.

I suppose the Hyundai battery would be pretty easy to come by if you get your battery changed for you at a Hyundai or Kia dealership.

Did you ever find out if the battery would void the warranty?

Does the ReLiOn have the ability to "jump" the car? By which I mean, have a bottom buffer that you can activate in an emergency?

 

[IanL]

Does the ReLiOn have the ability to "jump" the car? By which I mean, have a bottom buffer that you can activate in an emergency?

Haven't seen that anywhere, but they are marketing Li Ion batteries for gasoline cars now, and claim they can support very high cranking currents. e.g EBay link

 

[FLKiaEV]

Well, not a buffer reserve per se, but it should be possible to get a "jump" from another car (including an ICE car) just enough to connect the traction battery relay and allow driving. Then the DC to DC charging system would provide power to the accessories, even if the 12V battery was kaput. This would allow you to drive to an auto parts store or wherever to replace your 12V battery.

Another possibility is to carry one of these with you, just in case:

https://www.amazon.com/BUTURE-Portable-12000mAh-Quick-Charge-Flashlight/dp/B08TWZQFSG

You wouldn't need much amps since you're only engaging the traction battery and not turning over an engine.