stevos555

Is anyone running a lithium battery in their track car? Is the NA alternator regulator able to keep Lithium ATV battery demand of 14-14.4volt?

I read that alternator will overheat at low idle but don't think I am spending much time at low rpm anyway.

Ted75zcar

iTrader: (2)

I know nothing about the ATV battery, it may have functionality built in.

Lithium-ion batteries require a very specific charging algorithm as well as safety features typically facilitated with a dedicated Li-ion charge controller.

You would not be able to simply connect a traditional Li-ion battery to an NA charging system.

Reverant

iTrader: (10)

I would imagine that all these car-specific Li-Ion batteries have integrated circuits in them so that they can charge and balance the cells inside while maintaining all safety procedures (overcurrent/overvoltage/overtemp etc).

matrussell122

iTrader: (1)

I have been running one without issue. Also know of a few other members running the same one without issue.

Ted75zcar

iTrader: (2)

Probably right, but should be verified. Improperly charged Li-ion cells have a way of failing catastrophically. The term used in my current industry is "Rapid Thermal Disassembly".

Erat

iTrader: (5)

I don't really have Miata specific info here. But i figure any info is better than none.
I run lithium on my motorcycle. It's been fine so far.

I also run lithium on the race boat, but it doesn't have a charging system (total loss system). I can say, it only runs at 12 - 12.7 volts and has lasted 30+ minutes of use. Sometimes it gets the charger between heats.
It is this brand. https://braillebattery.com/collections/intensity
Says it's compatible with all automotive systems. I'm sure you can call and ask about race Miatas and such they'll probably have an answer.

And i'm guessing you or anyone on this forum for that matter doesn't want to spend nearly that much on a battery, and i get it. Their AGM batteries are just as good, the weight is the same for the most part. I've ran them before on different things. The blue Miata i sold had one.

They always want you to use their charger and i do, but i've also used my NOCO charger that has a lithium setting and it seems to be fine. No fires or explosions yet on any of my lithium batteries.

afm

iTrader: (3)

And yet they don’t. They’re very overpriced plastic shells on some cells and some copper straps.

The only one that even has a transistor in the main current path is the Antigravity ReStart, which uses it to cut power before the battery totally dies.

Shorai batteries have individual cell taps, but that’s for external balancing off a wall charger.

That being said, LiFePO4 batteries (absolutely none of these are traditional LiPo/LiCo batteries) are safe and work fine on charging systems meant for lead acid. They don’t last forever, but nothing does. Send it and buy a new one if you wear it out.

Reverant

iTrader: (10)

This one does have a full BMS inside it:

https://www.boschautoparts.ca/en/pow...-ion-batteries

I've seen quite a few different ones that look exactly like the Bosch one (the "Test" button is a dead giveaway), so I suspect that those have the BMS inside too.

afm

iTrader: (3)

“Full BMS” is not quite precisely defined. While that Bosch does balance low-voltage cells (unlike all previous ones linked in this thread, and unlike those used by hundreds on this site), that Bosch does not and cannot affect the charge “profile” (saturation voltage, rate, etc) of the whole pack, because that requires active electronics on the main current path.

Also, many packs have a test button (a tiny voltage testing circuit and some LEDs) and no internal balancing. Clearly that Bosch is the exception with its actual balancing.

Back to my original point: with respect to “all these car-specific” batteries being smart: almost none are. At this point, the majority of track Miatas I encounter have LiFePO4 batteries that are essentially just OTS cells in a plastic box. I’ve been using them in street cars for 7 years. I’ve also cut a few open. They work very well.

stevos555

Thank you all. I was originally paranoid about the stories of lithium batteries melting or causing fires if they are used not as intended. It seems based on a wealth of knowledge here and your user experiences with the same or similar batteries in motorsport application, I am getting more comfort with using this in a track car.

Reverant

iTrader: (10)

My understanding is that Lithium-Iron batteries will charge just fine on any voltage between 12.9-13.8V. Above that and you risk damaging the cells?

LeoNA

I ran a shorai and it burned out my regulator which in turn took out my MS3. I was using it as a daily which was part of the problem. There is always some phantom draw that will draw the battery down and then at start up the alternator seems to work extra hard. My thought is that the low internal resistance of the LiFe batteries allows for a higher rate of charge which overworks a reg alt. I have a few friends that are using them with no issue but they purchased the shorai charger and plug them in every night.

stevos555

Good tip. Cheap investment in a lithium maintainer vs new MS3 plus used Alt.

TNTUBA

iTrader: (1)

Been using a "Anti-gravity" battery with the "restart" feature. Has a built in BMS and low voltage safety protection built in. Amazing battery and crazy light. Discovered them at the PRI show last year.

stevos555

Wow - that's a $660 priced battery. Can't put a price on safe ..

HarryB

I would not want any other lithium chemistry cells other than LiFePo nowhere near my car. LiFePo is indestructible when compared to the rest, and considered quite safe. Even in the electric Formula Student environment where rules are paranoid about safety (and rightfully so), LiFePo are treated as a separate category. Nevertheless, I would like to have at minimum individual cell voltage and temperature monitoring, balancing, plus the ability to shut off charging/discharging if anything goes out of the expected range. Plus a flameproof (UL94V0 or higher) enclosure around the whole thing.

Bronson M

iTrader: (1)

I'm going on 3 years of of using RC car based LifePO4 lithium's, I balance them twice a year and they are never very far off. The main thing with any lithium batter is to not over charge or over discharge the cells. The alternator charges by maintaining a set output voltage and tapering off the amps as you approach the set voltage so the charging scheme works perfectly with a lithium battery. As for discharging, don't leave your key on over night......but that kinda applies to lead acid as well. Most of the "car" or "motorcycle" based batteries use the tubular based A123 format lifepo4 cells, I use the pouch style....can't really say one has a drastic advantage over the other. There's a theory that the A123 style keeps higher pressure on the cells as they outgas but you have to abuse the cells to get them outgas. The autocraft based battery at $100 and available at advance makes a lot of sense even if you can't balance the cells.

Erat

iTrader: (5)

So i have to state right off the bat, i'm pretty ignorant when it comes to lithium batteries. I've ran down the race bot battery pretty far, less than 10v multiple times. The boat doesn't have a charging system, not much i can do about it. I also charge it with the charger all the time. I'm sure this charger is smart enough to know (lithium setting on the noco, and the one it came with) not to overcharge. I'll leave the charger on for 7+ days at a time. Even after the little green "done" light is on. Haven't had a problem. Same thing with the lithium on the bike. I've honestly never even taken my DMM to it to see what it's at when off, starting, idle / charging. I could possibly do that tomorrow. I never gave two thoughts to lithium and its dangers. If you think about it, lead acid can be just as dangerous with it releasing hydrogen gas and all.

stevos555

The Autocraft battery appears to be LI-Ion not LIfe-PO4. The LI-on requires more voltage 13.5-14.4 vs Life-PO4. I could not find the box that was small to fit this battery yet. Keep searching for UL rated electronic poly box.

afm

iTrader: (3)

They're LiFePO4. They used to be the best value in town (especially with constant 25% off coupons from Advance Auto), but they're not as huge of a value as they used to be.

"Lithium Ion" is a broad term that includes all LiFePO4 batteries. While the colloquial use of "Li-Ion" often implies a distinct set from "LiFePO4" (namely LiPo or Li-Co batteries), it is actually a superset that includes many chemistries.