Maybe I just haven't been paying attention with regard to race/regular cars, but there's a lot of guys using Lithium batteries in overland / exploration vehicle builds over on other forums, which of course got me thinking about whether it's worth it to switch to one in my rally car (and/or other vehicles). Seems that they are smaller, lighter, and fairly similar in price to higher-end AGM batteries like Optimas. They also seem to have much longer lifetimes and be less affected by vibration, etc.
So, what's the catch? Why aren't these being sold at every Walmart and put in every crossover from the factory? The only thing I seem to see noted here and there is that they don't like the extreme cold much (not really an issue for me in the mid-Atlantic where it never gets colder than the teens, really). My jump-pack (NOCO) is Lithium and will start a dead car, so doesn't seem like it's an issue for cranking amperage.
In reply to irish44j (Forum Supporter) :
First problem is wrong voltage- so you have to redo the entire charging system to be correct for whatever lithium chemistry you choose to get. Second is enough current to crank the engine- you can get them, but for +200CCA, well... Third is to make sure the conditions are correct for the chemistry- you can't charge a LiFePO4 battery under 34F.
The biggest pair is charge voltage and the right packs to get enough CCA, to me at least. Especially when you can get some very light AGM batteries for a lot less money.
^^those are the kind of things I heard years ago when I looked into this topic briefly, but the fact that there are so many LiFePO4 setups on Amazon (as well as plenty marketed for racecar use) made me wonder if technology had advanced enough to mitigate those limitations for use in a standard car. Though I suppose most racecars would not be running or needed to charge under 34F (though rally cars do, in many cases............)
Looking back, I guess that explains why most of the overland guys still have a standard battery along with a LiFePO4 in their circuit - one for cranking and the other for hotel load.
j_tso
Dork
1/7/23 11:26 p.m.
Aren't they a lot more expensive, like over $500? That's the main reason I think they aren't widely adopted.
Race car owners don't really need cold weather performance and are probably fine putting the battery on a tender when not in use to keep it charged and to top up any charge the car's charging system can't supply. They're definitely not comparable in price to lead acid or most agm batteries, at least not for decent quality ones. A direct replacement for my cayman battery is 4-5x the cost of a stock battery, which I believe is an agm. Fwiw Porsche did actually offer a lithium battery option on some gt3rs I think. But aside from being wildly expensive I believe it was also a slight reduction in cranking power and supposed to be for track use only.
The way I see it, funny/small batteries are OK for race cars because they are typically only used in environments where there's a lot of support equipment around -- tow vehicles with big batteries for jumping, jump packs stored in the trailer, or at the very least a bunch of other folks around who are likely to be able to help out. If the battery is dead and it won't start it's annoying but not usually a big deal.
OTOH street cars need to be self-sufficient, and to me that means they should get a normal type of battery with lots of reserve charge and no weird charging rules.
I was on the fence with this for at least 2 years. I eventually bought a Braille lithium for the racecar. Yes, it was expensive, but it weighs FOUR POUNDS. When I took it out of the shipping box, I thought someone was screwing with me. I thought "there's no way this tiny, lightweight, hollow can can start this car." But then I connected the 2GA battery cable to this ridiculous little lightweight "empty" shell, and the motor spun over faster than it ever had before. It has been flawless for over 2 years since installation. As far as support equipment, I've never needed anything other than than the bespoke trickle charger and my ignition key. The improvement in cranking power is incredible, and dropped 30+ lbf over the previous BCI 74 Optima (-54 lbf over factory BCI 49) and another 8 lbf of cable. Granted, it's sensitive to over-discharging, but I don't do that. The car also starts pretty well, so there's never any prolonged load on it. Would buy again, 5 stars.
I ran LiFePO4 batteries in my Swift gt for a couple years. It was about the size of a can of beer and was fine for daily driving until temps dropped below zero, then it would struggle. It always started the car but it usually took a few tries until the battery warmed up. The only problems I had were my own fault when I would leave the lights or the key on and run it down. I don't think I ever paid more than $100 for a battery
I looked at this for the rally BRZ, and ended up using a massive, heavy Optima instead- for a pointy end build, I'd go with a lithium thing for sure, but I decided against it when thinking about how many times a deep reserve of cranking power saved our last two cars from a DNF. I'd also probably want it out of the cabin, just because of what that sort of battery does when it blows up.
I'm going to run a pc680 in D2D. Outside of starting and either ecu/pdu or just ECU, I have no big electrical demands. Lights are all leds. Roll up windows, manual everything....
I've had one in my motorcycle for going on ten years now. That's right - one single battery lasting ten years. To be honest I think it's getting close to the end of it's life but it's still just always fires right up. And I never put it on a charger or anything.
I'm still on the fence about whether I'd trust one for a daily driver though.
I run antigravitys in all of my motorcycles and really the only drawbacks in my eyes are price, need a special charger (most are compatible anymore), and them needing "woken up" in cold weather.
We ran one at the Challenge I think in 18. Everything was great until the alternator started putting out 20+ volts. Not fun trying to get a smoking battery out when you have a real good battery tie down. That said we have a secret weapon that might be ready for this year's Challenge.
irish44j (Forum Supporter) said:
^^those are the kind of things I heard years ago when I looked into this topic briefly, but the fact that there are so many LiFePO4 setups on Amazon (as well as plenty marketed for racecar use) made me wonder if technology had advanced enough to mitigate those limitations for use in a standard car. Though I suppose most racecars would not be running or needed to charge under 34F (though rally cars do, in many cases............)
Looking back, I guess that explains why most of the overland guys still have a standard battery along with a LiFePO4 in their circuit - one for cranking and the other for hotel load.
How they are used is really different, too. You don't need 100A-Hr in a car battery, you need cranking power. Whereas in a camper, you don't need 300A for a few seconds, you need power for a long time. (as you point out)
Getting 300A out of a lead chemistry is pretty easy- almost trivial these days. Doing that for any LI chemistry is quite a bit more complicated. Can be done, but you need to spread the current out among alot of cells.
If this is a race car w/o an alternator (which there are a lot of out there), then a number of lithium batteries make a ton of sense. Especially if you do the cold cranking with a booster battery, and the if it needs to restart, a nominal battery would work. But if you know the energy it takes to finish a complete race, you can customize the battery so that it can power everything w/o charge. For that, there are a ton of smaller batteries that you can get.
alfadriver said:
In reply to irish44j (Forum Supporter) :
First problem is wrong voltage- so you have to redo the entire charging system to be correct for whatever lithium chemistry you choose to get. Second is enough current to crank the engine- you can get them, but for +200CCA, well... Third is to make sure the conditions are correct for the chemistry- you can't charge a LiFePO4 battery under 34F.
The biggest pair is charge voltage and the right packs to get enough CCA, to me at least. Especially when you can get some very light AGM batteries for a lot less money.
My 2017 BMW M4 came stock from the factory with a Lithium battery. Same with my 2021 BMW S1000RR.
They are both 12 vdc
In reply to irish44j (Forum Supporter) :
Lithium is fine. Just make sure you disconnect from the car as they do not like to be discharged all the way.
Being a racecar disconnecting is not. Big deal, otherwise look for one of the ones that have a safety turn off built in. It will shut itself off before completely discharging and you can override it once you are ready to use it.
j_tso said:
Aren't they a lot more expensive, like over $500? That's the main reason I think they aren't widely adopted.
Oh, much more than that. A Group 24 sized battery is about $1000.
I nearly bought one marked down to $200 on general principle. The battery was so light it felt like an empty case.
The prospect of spending $200 on an unknown battery that I could not return kept me from actually buying it.
Slippery said:
In reply to irish44j (Forum Supporter) :
Lithium is fine. Just make sure you disconnect from the car as they do not like to be discharged all the way.
Being a racecar disconnecting is not. Big deal, otherwise look for one of the ones that have a safety turn off built in. It will shut itself off before completely discharging and you can override it once you are ready to use it.
I thought one of the benefits of using Litium batteries vs Lead Acid is the ability to be discharged completely? At least that's what the camper crowds are preaching these days. They claim lead acid is only good for 50% max discharge before damage occurs. Is that not the case?
In reply to Slippery :
"12V" isn't really 12V. And the side effects of getting it wrong are very different.
Especially for LiIon chemistries.
But I ruined a set of LiFePO4 batteries by treating them like lead acid batteries. Thankfully, it was a cheap experiment.
Also, quickly over discharging some Li batteries can cause a fire, too.
WillG80 said:
Slippery said:
In reply to irish44j (Forum Supporter) :
Lithium is fine. Just make sure you disconnect from the car as they do not like to be discharged all the way.
Being a racecar disconnecting is not. Big deal, otherwise look for one of the ones that have a safety turn off built in. It will shut itself off before completely discharging and you can override it once you are ready to use it.
I thought one of the benefits of using Litium batteries vs Lead Acid is the ability to be discharged completely? At least that's what the camper crowds are preaching these days. They claim lead acid is only good for 50% max discharge before damage occurs. Is that not the case?
In a car, you rarely need to completely discharge a battery- so that's one thing. (for cars, CCA is more important than capacity for a car).
The other big benefit for Li batteries is the combination of total discharge range plus the number of times you can do that. So for a duty where the energy draw is pretty consistent- a smaller Li battery may last a lot longer than the lead battery- so in terms of cost over the life of a Li battery- the cost outlay could be very similar. But if you are not worried about 3000-4000 battery cycles, well...
I'd have to look more into what a good full cycle is, but I have also seen lead batteries totally die if fully discharged to nothing. so...
alfadriver said:
Also, quickly over discharging some Li batteries can cause a fire, too.
I don't think they've done that for a long time.
https://classicmotorsports.com/forum/grm/cheap-lightweight-battery-suggestions/57030/page2/
https://grassrootsmotorsports.com/forum/grm/what-is-the-current-state-of-lightweight-batteries/178429/page1/
And I'm pretty sure there a few more threads
In reply to Peabody :
Finding a few examples of Li chemistries that don't catch fire when over discharged does not stop the ones that do catch fire when over discharged in current. The point is that you have to know what you are getting.
Like getting a LiPo can be very troublesome.
But if people want to take the risk, hey, it's your car. And house, and passengers....
It's not the chemistry it's the in built circuitry that prevents them from discharging too quickly
¯\_(ツ)_/¯ said:
I looked at this for the rally BRZ, and ended up using a massive, heavy Optima instead- for a pointy end build, I'd go with a lithium thing for sure, but I decided against it when thinking about how many times a deep reserve of cranking power saved our last two cars from a DNF. I'd also probably want it out of the cabin, just because of what that sort of battery does when it blows up.
Yeah, as you know I also have a massive, heavy Optima yellow top in my rally car as well. Not that weight in the rally car has ever been a real concern of mine (as you also know, lol).
Mostly this just got in my head since I was reading about adding second batteries to expedition rigs and such, and was curious.
In car batteries, are we standardized on one thing when we say "lithium" at this point?
I know very little, but have this sort of soup of Lithium Ion, LiFe, LiPo (or Lithium Polymer?) terminology in my head, and I don't even know whether that's three distinct chemistries/architectures, and whether the batteries that see people running out of R/C races (or SEMA) to dump sizzling piles in the parking lot is consistently different from the batteries on intercontinental flights in people's laptops... e.g. the computer I'm writing this on now claims in the battery info to be using one "Li-Polymer" battery and one "Li-Ion" battery.
