Lithium (LiFePO4) batteries

[grantw]

Has anyone else been considering replacing their leisure battery or their starter batteries (or both) with Lithium batteries?

I've been taking a close look at these and will probably take the plunge on a minimum of 6 of these in the next 12 months.
https://beta.ev-power.eu/LiFeYPO4-batteries-12V-1-1/

The two biggest advantages of these are the rate at what they charge and how much of the available capacity you can use. For my given case buying 6 20ah batteries would give me a total of 120ah. With nearly all of that usable. At the recommended cut off level these will still read 11v and should still start a cruiser.

Assuming I upgraded my alternator from an 80amp one and that it was able to sustain a steady 14.8v max for charging the batteries could be charged from flat to 80% in one hour and to 95% in one and a half hours. Which I think is pretty impressive. This seems to be much better than anything a lead acid battery can do.

I'm not sure how these do compare with the yellow top optima batteries though as they seem to sit in the middle somewhere of a SLA and lithium batteries. I'm hoping someone can add their experience of these

Is it unreasonable to expect the steady voltage out of an alternator to fully charge these at 80% of the alternators capacity?

Charge graph from http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

 

[Chas]

Sounds interesting, I don't have enough knowledge to comment though. What physical size are these batteries, are they similar to standard ones?

 

[grantw]

Sounds interesting, I don't have enough knowledge to comment though. What physical size are these batteries, are they similar to standard ones?

A bit smaller a single OEM 80ah battery 300mm x 195mm x 195mm
Each one of these is 181mm x 77mm x 167mm

So for the quoted amp hours (4) the lithium ones would be 181mm x 308mm x 167mm. The lithium batteries would weight 18kg and the lead acid would be 26kg. But of course you could actually use at least 70ah of the lithium compared to 20ah to 40ah of the lead acid.

 

[grantw]

One concern is for really heavy loads like winching.

These batteries have a max continuous discharge of 3c (3 times capacity) which with my example of 6 batteries would only give 360 amps of continuous current where as with winching I think loads can be 400amps plus. The alternator should pick up this shortfall of you can just have one or two more batteries.

Now the wise amongst you after that comment will be thinking what about starting - don't worry these can output 10c or 1200 amps in short bursts. These particular batteries can do this for 5 seconds every minute.

 

[StarCruiser]

I would have thought winching would be OK as you won't be drawing anywhere near the peak current all the time, only when under heavy load and as you say the alternator SHOULD pick up some of the load. However, not having looked into this mind, are these batteries suitable for charging byvacstandard car alternator? You have to be a bit careful charging Lithium batteries I believe. The other thing is if they suffer damage they can catch fire and that fire is intense and non extinguishable. This fact alone would make me stay with standard car batteries until convinced otherwise.

 

[grantw]

I would have thought winching would be OK as you won't be drawing anywhere near the peak current all the time, only when under heavy load and as you say the alternator SHOULD pick up some of the load. However, not having looked into this mind, are these batteries suitable for charging byvacstandard car alternator? You have to be a bit careful charging Lithium batteries I believe. The other thing is if they suffer damage they can catch fire and that fire is intense and non extinguishable. This fact alone would make me stay with standard car batteries until convinced otherwise.

Charging wise as long as the voltage isn't going above 14.8v from the alternator then all is good - same with a lead acid battery really.

Safety wise these aren't the crazy type of lithium we have in our phones, laptops etc and that we see on the news all the time but a much safer version. Severe damage to these is all a but undramatic actually. Well compared to a normal lithium battery.

This is a video with a nail gun being fired into one of these batteries.

With that kind of reaction i'm almost inclined to think it could be safer than a lead acid battery?

 

[Chas]

The other thing is if they suffer damage they can catch fire and that fire is intense and non extinguishable. This fact alone would make me stay with standard car batteries until convinced otherwise.

I had heard of the possibility of fire if damaged but I didn't know it was non extinguishable. In the event of an accident severe enough to damage the batteries under the bonnet there could be the possibility of being trapped in the car on fire, I think I'll stay with standard too.

 

[Chas]

With that kind of reaction i'm almost inclined to think it could be safer than a lead acid battery?

Charging wise as long as the voltage isn't going above 14.8v from the alternator then all is good - same with a lead acid battery really.

Safety wise these aren't the crazy type of lithium we have in our phones, laptops etc and that we see on the news all the time but a much safer version. Severe damage to these is all a but undramatic actually. Well compared to a normal lithium battery.

This is a video with a nail gun being fired into one of these batteries.

With that kind of reaction i'm almost inclined to think it could be safer than a lead acid battery?

Sorry Grant that doesn't convince me, as they say "No smoke without fire" and there was considerable smoke, also the commentary said only 3. something volts there.

 

[Crispin]

It would be interesting to see this. You'd need a proper LiFe charger and battery management system for it.
You can't just swap out the existing one.

It seems they don't have the same problem as other Li batteries when stored full which is a big bonus.

One thing I wonder about is the charging / discharging of them. Li batteries go bang when they're stressed from charging. Now if you're winching the battery is working hard. You stop winching and the charger says "here, let me fill you up". You start winching again.

At best I would put it in a steel box
As Chas pointed out - fire from these batteries is not normal combustion but a thermal runaway from the chemicals. Once started, all you can do is control around it and enjoy the display.

 

[grantw]

I'm still not sure if the lifep04 incarnation of these batteries are any more dangerous than lead acid. There is no shortage of lead acid batteries giving a nasty bang/catching fire. (https://www.google.co.uk/search?q=l...hUKEwjmic3OrbfPAhWDL8AKHbabBkoQ_AUICCgD&dpr=1)

Crispin, I don't think for these you would need a specific charger as most alternators output voltage matches the charging voltage of these batteries (14.8v.) There are definitely Li batteries being advertised for both bike and car use that say you don't need a special charging system. (http://www.batterymasters.co.uk/Pro...T6ZYbyWiKXjfT2wS-FB3QhJeHuK3yUsZm4aAjdY8P8HAQ)

I'm still going to go this way and will just have to feed back my results. I was just hoping someone had gone before me though I don't know if I will replace starting batteries or just use as a leisure battery. It would be fairly easy to have a low and high voltage cut off relays that would prevent anything crazy happening.

 

[Gary820]

We use them at work on M3 and M4 models. Only precautions we have is for battery charging, we had to set the charge voltage lower as normally set at 14.8v . The cars intelligently charge themselves so no risk of over charging. Battery mounted in the boot as normal

 

[Crispin]

That's quite interesting. I did not know they're that different to other Li chemistry batteries.

As for the Pb batteries going bang - in their defence, most of those pics pics look like not-a-car-use and google image shows the worst of everything

Will certainly be interesting to hear how it goes.

 

[Firewout]

Regarding battery fire:
[QUOTE="As for the Pb batteries going bang - in their defence, most of those pics pics look like not-a-car-use and google image shows the worst of everything
.[/QUOTE]
In the >20 years I've been working at the fire station, we had 3 or 4 Pb batteries burst and spraying acid around. This on a fleet of 20 fire trucks with 2 big batteries each. Mostly when starting/jumpstarting. Luckily the acid stayed confined in the battery compartments, it's just messy to clean up.

I've been to a training for TEAL / lithium fire extinguishing. This stuff catches fire spontaneously when in contact with air or water. We tried to put it out with different media. Powder, water, foam, caffs, sand etc. Water from a garden hose and foam gave a violent explosive reaction. Best result was controlling the fire with the fine mist of a high pressure cleaner. A lot of smoke and popping but no explosions.

 

[grantw]

@Gary I didn't know they had made their way into cars. For high performance cars it makes sense though. I did a little reading and it looks like the ones BMW use are a different LI chemistry (so probably lighter) which is why the charge voltage is lower (13.8v by the looks of it) I wonder if breakers know how much these batteries are worth yet. Thanks

@Crispin There are quite a few different chemistries with this one being the safest. I'm guessing your experience is with LiPo packs for your drones? Those are the "scary" ones. These have the HUGE weight advantage though. Pb batteries have an energy density of 50 watt hours per kg where as LiPo has 410. LifePO4 has around 110.

@Firewout I probably was being a bit dramatic about the lead acid battery problems - I was just tyring to get my point across at how much safer this battery chemistry is over other lithium alternatives. Was very interesting to read your input

@Chas I haven't really been able to find any videos of this type of batteries being on fire, there are a one or two forum posts but nothing conclusive. By the time I get around to purchasing these hopefully there will be more information about.

Thanks for the input and thoughts guys.

 

[Crispin]

That's quite interesting. I did not know they were that much lower that the LiPo batteries. Still a lot better than than Pb. I wonder when they will become more common place. Like Gary said, they stock on some BMs.

@Gary820 - any idea what the current demand is on a modern-day car like a BM? Take an 80 for example - after starting the alternator tops up the battery, runs a few basics. On something like a BM / Audi / other etc it must work quite a bit harder.

 

[Firewout]

@grantw : if you're standing next to a bursting battery, it will get very dramatic indeed. Sulfuric acid is a nasty bitch when it gets on your skin. We've just been lucky no one got hurt.

 

[Gary820]

@grantw it's the only models we currently have them fitted to ( Apart from hybrids and i cars but that's another subject) they're lighter and smaller then the equivalent ah agm, high performance cars though, have carbon props and roofs etc.
They get sent to us packaged on a small crate rather then just a loose battery and warning sticker etc on the box, bloody expensive too!

@Crispin
Current demand really comes down to the spec tbh, starters will draw less current then the one on my 80, even on the big diesels, quite a small unit.
There's the media systems, the electric steering rack (some have rear steer and 24v front steering), the drivers assistance systems etc, the management systems for engine, transmission/drivetrain, suspension as can get active dampers and the active anti roll bars are now electric.
Most batteries now are a fair size and large capacity agm.

We have models with 2 and sometimes 3 batteries as standard!
Alternator only works at the rate needed and power management will switch off systems it deems not needed, eg the control unit to adjust the electric seats turns off after started the journey.

All the systems really add up on high spec motors and can have quite a few fuse boxes, lots of heavy duty cable too.
Not exactly given a direct answer but there isn't really one lol.

 

[AlexanderVanBaelen]

Hi Grant,

Any progress on this topic? I am also looking into this option from the same seller.

My current concerns are:
Using it as a leisure battery and charging it not only with solar but also with the alternator. I believe the alternator puts out to much current for the packs. Also I read that these batteries don't care to be fully loaded, so to be safe it might be better to always set all the load levels a bit lower to increase longevity. When you would charge them via the alternator I also read that as they can charge so fast it might put a big strain on the alternator, making it push at 100 % for to long which would then lead to premature failure of the alternator.

When looking at the battery price I am willing to put of the money. Not sure if I would spend the money for a BMS (250 EUR on a 600 EUR battery in my case). However I do get a bit worried when I look at the additionals to install to have it work. When looking at the Victron website I see so many required installs to make this work that all these extras easily add up to more then the batteries cost.

I have however also seen a charger from Australia for LiFePO4 from Redarc. This charger is pricy, but turns 9 to 32 volts into 12 volts and can act as MPPT for you solar as well, which makes it a money saver in same way.

Looking forward to hear what you have done!

 

[IRLGW]

isn't there and issue with Lipo battery having a low did-charge threshold? I know that the standard 3.7v cells wont take a charge if they fall below 3.0v and you need to recover the individual cell before it will take charge again. They also don't like being charged in series which is what causes most damage to them via overheating but if they had a really smart charging pcb then they may work in a high demand applications. Those palm sized jump packs are Lipo I think and allegedly can jump start a 2.5lt 4cl diesel but never used one. might be a good place to mount them behind your front grill to keep them nice and cool

 

[grantw]

isn't there and issue with Lipo battery having a low did-charge threshold? I know that the standard 3.7v cells wont take a charge if they fall below 3.0v and you need to recover the individual cell before it will take charge again. They also don't like being charged in series which is what causes most damage to them via overheating but if they had a really smart charging pcb then they may work in a high demand applications. Those palm sized jump packs are Lipo I think and allegedly can jump start a 2.5lt 4cl diesel but never used one. might be a good place to mount them behind your front grill to keep them nice and cool

LiFePO4 are a different chemistry to lipo cells which makes them much more stable but also alot heavier. For instance if you pierce a lipo with a screw driver all hell breaks loose with fire and smoke. With a LiFePO4 cell you are lucky to get a little bit of smoke.