lithium question

To be pedantic, there are almost no EVs with LFP batteries except a few homebuilts. All manufactured EVs use some other lithium chemistry, typically lithium cobalt. LFP (short for Lithium Ferris Phosphate) are less energy dense, but much more fire resistant. I'm just pointing this out because many people will say the lithium batteries are unsafe and burn, just look at the Tesla and Boeing fires, without understanding the difference.

HMS Beagle wrote:
To be pedantic, there are almost no EVs with LFP batteries except a few homebuilts. All manufactured EVs use some other lithium chemistry, typically lithium cobalt. LFP (short for Lithium Ferris Phosphate) are less energy dense, but much more fire resistant. I'm just pointing this out because many people will say the lithium batteries are unsafe and burn, just look at the Tesla and Boeing fires, without understanding the difference.

Hmmm. Might be a misunderstanding of terms on my part. I’m not an expert. Presently all the Tesla model 3 SR plus models sold in China and Europe are using LFP batteries. The US made model 3 SR plus (now just called standard range) are available with the LFP battery. They are a little slower and heavier. Presently the LFP battery for these models come from China but the Tesla Nevada will also be building these in the new year.

This is a fairly recent development. All over the last 3 to 9 months depending on factory.

Heads up, all the long range models still use the normal Tesla batteries. They are not LFP. Lithium cobalt etc.

https://www.greencarreports.com/news/1133942_tesla-plans-shift-to-lfp-cells-for-model-3-and-model-y-likely-with-us-production

pianotuna it really seems you have a vendetta against LifeP04 batteries, I see people limiting their max charge Voltage. I have not tried that yet as I am still building my system.

StirCrazy wrote:

S Davis wrote:


EVE LifeP04 cells are 10% to 90% for 3500 cycles, they should still have 80% capacity at that point. If so these should outlast me.

I think your missreading that a bit.. the industry standard is that the cycles they list are based off a 100% usage. they recomend 10-90% use range and that will extend your cycle life possibly up to 5000-7000 cycles, before you reach that 80% threshhold. then that 80% could be maintained for another 10 years or longer, if you treat them good.

Steve

Yes you are correct, that is their recommendation for max cycles. Pulled this from the spec sheet, they consider a cycle from fully charged to 2.5 volt cut off.

A fte r sta nda rd char ged and 30 mins res t, discharge to 2.5V cutoff with the current of 1.0C(A) at (25±2) °C, and then start the next cycle, end with the capacity decrease to 80%
of the initial capacity. The number of cycles is defined as the cycle life of the battery.

HMS Beagle wrote:
All manufactured EVs use some other lithium chemistry, typically lithium cobalt. LFP (short for Lithium Ferris Phosphate) are less energy dense, but much more fire resistant. I'm just pointing this out because many people will say the lithium batteries are unsafe and burn, just look at the Tesla and Boeing fires, without understanding the difference.

If you google ice fires--there were 150,000 in USA last year. The fire problem is over blown, and in my opinion, a negative advertising campaign.

The Bolt batteries were defective from the factory that made them. They are replacing them all.

From a seller of LI: https://www.solacity.com/how-to-keep-lifepo4-lithium-ion-batteries-happy/

Lots of talk about achieving ‘max cycles’ (most anything can ‘and should’ be optimized, eh?), but from my own myopic perspective, with soooo many available charge cycles, I don’t bother much engaging in all that might worry - Were I to lose say 10% of 5,000 LFP charge cycles (due to my own reckless inattentiveness?? lol), I’m still quite happy (in exchange) to enjoy the ‘real-use’ benefits and longevity of LFP…One way or another just about everything in this universe comes with an expiration date, eh - In fact, I’ve yet to learn of anything that gets a waiver :) !! JMHO

3 tons

3 tons wrote:
Lots of talk about achieving ‘max cycles’ (most anything can ‘and should’ be optimized, eh?), but from my own myopic perspective, with soooo many available charge cycles, I don’t bother much engaging in all that might worry - Were I to lose say 10% of 5,000 LFP charge cycles (due to my own reckless inattentiveness?? lol), I’m still quite happy (in exchange) to enjoy the ‘real-use’ benefits and longevity of LFP…One way or another just about everything in this universe comes with an expiration date, eh - In fact, I’ve yet to learn of anything that gets a waiver :) !! JMHO

3 tons

Yes the whole "maximize life cycles" for LFP is one more hangover from the old lead-acid days because cycles were so few back then.

Reisender wrote:

StirCrazy wrote:

Reisender wrote:

StirCrazy wrote:

S Davis wrote:


EVE LifeP04 cells are 10% to 90% for 3500 cycles, they should still have 80% capacity at that point. If so these should outlast me.

I think your missreading that a bit.. the industry standard is that the cycles they list are based off a 100% usage. they recomend 10-90% use range and that will extend your cycle life possibly up to 5000-7000 cycles, before you reach that 80% threshhold. then that 80% could be maintained for another 10 years or longer, if you treat them good.

Steve

Yep. This is why Hertz rent a car is buying 100,000 base models of an EV that uses LFP batteries. An expected battery lifetime of a million kilometres vice other chemistries. You can pretty much run LFP to zero frequently without as much worry of damage. 10 to 90 is much better though. The sacrifice is they are heavier and performance suffers a bit from the higher end models.

We are kicking around the idea of putting something like a battle born in our new little trailer that comes with 2 x 6 volt AGM’s. The cheap skate in me says live with the AGM’s and wait a few more years and the price delta to come down. Guess we’ll see.

haha AGM, up here, are more expensive that some of the new LFP on the market. and if you can hook up a four 6V battery sety up in your camper you can build your own batter setup with prismatic LFP cells which is so much cheeper. Battle born is way over priced now, there competators in the market and I believe they all agreeded on a price trying to hold on to the prices they set when they were only one of 3 range.

Steve

Yep, they are pricey. But am I right? You seem to have a good handle on this. The trailer comes from the factory with 2 x 6!volt AGMs. Would an LFP 31 not be giving up a bit as far as useable amp hours? They are in a heated area so that’s not an issue.

you could be depends on the exact size of the 6V agms, but we can assume say 180ah??? then a 100 AH LFP would give you the same amount aproximatly of usable , but in a pinch with the 6V you could go down to 20% which means in a emergency you would hve a 144AH capacity. I dont like to size LFP to use the "equivalant" usable AH I like to take advantage of the size and weight and get more AH in a lighter and smaller package. so for me I would realy go with two of thoes batteries, run them nice and take that cycle life through the roof and when you need it you will have a total of 200AH for use in an emergency, but you'll probably never buy another set of batteries in your life.

Steve

No. Just any charger could cause damage. You need to see the mfgr recommendations. Most require a charger that can be set to charge no higher than 14.4.

StirCrazy wrote:

Reisender wrote:

StirCrazy wrote:

Reisender wrote:

StirCrazy wrote:

S Davis wrote:


EVE LifeP04 cells are 10% to 90% for 3500 cycles, they should still have 80% capacity at that point. If so these should outlast me.

I think your missreading that a bit.. the industry standard is that the cycles they list are based off a 100% usage. they recomend 10-90% use range and that will extend your cycle life possibly up to 5000-7000 cycles, before you reach that 80% threshhold. then that 80% could be maintained for another 10 years or longer, if you treat them good.

Steve

Yep. This is why Hertz rent a car is buying 100,000 base models of an EV that uses LFP batteries. An expected battery lifetime of a million kilometres vice other chemistries. You can pretty much run LFP to zero frequently without as much worry of damage. 10 to 90 is much better though. The sacrifice is they are heavier and performance suffers a bit from the higher end models.

We are kicking around the idea of putting something like a battle born in our new little trailer that comes with 2 x 6 volt AGM’s. The cheap skate in me says live with the AGM’s and wait a few more years and the price delta to come down. Guess we’ll see.

haha AGM, up here, are more expensive that some of the new LFP on the market. and if you can hook up a four 6V battery sety up in your camper you can build your own batter setup with prismatic LFP cells which is so much cheeper. Battle born is way over priced now, there competators in the market and I believe they all agreeded on a price trying to hold on to the prices they set when they were only one of 3 range.

Steve

Yep, they are pricey. But am I right? You seem to have a good handle on this. The trailer comes from the factory with 2 x 6!volt AGMs. Would an LFP 31 not be giving up a bit as far as useable amp hours? They are in a heated area so that’s not an issue.

you could be depends on the exact size of the 6V agms, but we can assume say 180ah??? then a 100 AH LFP would give you the same amount aproximatly of usable , but in a pinch with the 6V you could go down to 20% which means in a emergency you would hve a 144AH capacity. I dont like to size LFP to use the "equivalant" usable AH I like to take advantage of the size and weight and get more AH in a lighter and smaller package. so for me I would realy go with two of thoes batteries, run them nice and take that cycle life through the roof and when you need it you will have a total of 200AH for use in an emergency, but you'll probably never buy another set of batteries in your life.

Steve

Thanks Steve. That’s probably the way we’ll go. Although we’ll probably give it a go with the 2 AGM’s for the first season. This little trailer has hydronic heat and hot water so no big furnace fan load. I’m told by other T@B 400 owners that the 2 6 volts and solar panel are good for at least a few days of dry camping. But I know where we like to camp and quite often there is shade involved soooooo.... ,, the solar panel may be of limited use.

The reality is the tow vehicle is a Tesla with an 82 KWH battery so it will never be a crisis as we can just tap into that reserve via the 16 amp accessory port. We did some tests to insure this would work. But it’s extremely inefficient as it uses double conversion from DC to AC back to DC again. As well the car has to be “on” which wastes a couple watts right out of the gate.

A friend of ours bought a champion 2500 watt propane (dual fuel) super quiet genny from Costco. We are going to look at it and see if it would be handy for extended dry camping. We have a bigger champion for backup home power and are really happy with it but too big to drag with us. The little one is around 50 pounds so not bad. But we prefer not to have to drag a genny with us. Or at least not on a regular basis. But as you know, your and our area has a ton of great non serviced camp sites close to us. (We are in Vernon). It will probably be handy to have a little propane genny.

Cheers and thanks for the info.