Help me assess the value of lithium

[avanti]

Originally Posted by @Michael

As to the need for continuous shore power to keep the lithium warm, I recognize that as a constraint. But if it's -20F and my house has no electric, I'll be far more interested in preventing tens of thousands of dollars in damage from frozen pipes than in keeping my camper battery warm.

I agree with this. The risk of losing grid power is an acceptable one that we take all the time. In my case, the concern is the requirement of always having to store the vehicle somewhere where power is available. Lots of us have off-site storage locations without power. This is the biggest issue that is keeping me away from Lithium for now. I keep picturing us half-way across the country watching a frigid front heading toward my unattended van. Maybe I'll get over it someday...

[Davydd]

Originally Posted by markopolo

Victron's LiFePO4 battery: https://www.victronenergy.com/upload...s-Smart-EN.pdf

Storage temperature -45°C to +70°C

It could all be just a mix up about different definitions of storage such as somewhat ready-to-go (at least for discharge) storage at -4F compared to possible impairment if stored at -40F or colder.

It won't be the first time companies have screwed up their specs. Early on many had screwed up. -45ºC is equal to -49ºF. That is against every reference I've read about lithium ion phosphate batteries. But if true, they are better in storage than AGMs.

You can discharge at -20ºC (-4ºF) but you can't charge below freezing. Their charging at 5ºC minimum agrees with ARV's settings to turn off charging below 41ºF which is a bit conservative from below freezing convention.

[avanti]

Originally Posted by Davydd

There are a lot of armchair opinions from none lithium ion owners who have no experience.

Have you tried storing your van without access to power at -40? If not, your opinion on this issue (which is the only one that has been brought up) is maifestly "armchair".

Indeed, apparently any opinion that is based on data is "armchair" unless it is being made by the experimenter who actually collected the data. Except, of course, that a great many graduate students turn into experts without ever collecting primary data.

I find the repeated argument that only someone with first-hand experience has the right to a substantive opinion to be specious and tiresome.

[Davydd]

I've experienced -40ºF (same as -40ºC) only once in 51 years living in Minnesota. Maybe I've experienced colder many times on an exterior wing bridge of a US Navy ship in the North Atlantic dodging icebergs.

Maybe armchair is not the term to use. Maybe Chicken Little is. I find it specious and tiresome of someone without the common sense to understand lithium ion limits and understanding those limits and condescending to those who do. If you leave a Class B outside with AGMs you could permanently damage those batteries at -40º as well. Look it up.

[avanti]

Originally Posted by Davydd

If you leave a Class B outside with AGMs you could permanently damage those batteries at -40º as well. Look it up.

Except that you yourself have repeatedly reported the damage point for most Lithium chemistries as -4F, not -40; e.g.:
https://www.classbforum.com/forums/f...tml#post113324
Obviously the latter is an acceptable risk almost everywhere. No one has suggested otherwise. It would better to read a thread before repeating the same rhetoric over and over again.

I will simply ignore your "condescension" comment.

[coss370]

I think you might be going too far in your assumption. For one, there are many types of batteries and companies out there. Between your top of the line stuff to your crappy Chinese knock offs, the difference can be huge. There are definitely concerns about cold weather storage and charging with Lifepo4 batteries, but it would be wise for the owner to do some research and see what works and what doesn't work.

Excluding the possible cold weather issue, you are right the lith batteries are better all around. It's just a matter of cost. I don't get people who don't want to pay for it have to justify their position. It's bizarre

Originally Posted by Davydd

There are a lot of armchair opinions from none lithium ion owners who have no experience. Let's get one thing out of the way, Valence battery offerings has changed it's chemistry to LifePoMo4 from LifePoMgMo4 so the -40F is off the table from what I can tell. I'm getting Valence batteries from ARV. I think that changed when Lithiumwerks bought them.

The fears about lithium ion and freezing are way over the top in concern. The Twin Cities (Minneapolis/St. Paul) has had but two sub-zero overnight temperatures not reaching -4F this winter and now being February may not have another. It is perhaps the coldest major multi-million metro area in the US and perhaps Canada. Most people living in colder environs know how to take care of vehicles or if they don't they are damn fools. Simple. Heated storage or an electrical source which is mandated on homes outside by building codes. Remote storage without shore power is the only concern. Simple again. Don't buy lithium ion if you are in that situation, but I bet there are few here with that limitation.

I have as mentioned 6 years experience with lithium ion. My first three winters I stored outside in Minnesota with a 20a hookup with no problems. The batteries were under the van with 10a total electric resistance heating pads. Most all companies now including my new ARV store lithium batteries inside the cabin. So you still have to be concerned with charging batteries when below freezing but I think you can safely disconnect them if you have to and then getting underway you can bring the cabin temperature above freezing easily and in turn the batteries for charging. In disconnected storage they are better than AGMs in self discharging rate. In other words they will last the winter better. Self heating batteries or heating pads operating off the batteries themselves can be utilized as well.

I've experienced operating Class Bs with wet and AGM lead acid batteries and now lithium ion. I had many more battery concerns and failures with lead acid and more benefits from lithium ion to never go back. I've been underway boondocking in -15F temperatures with lithium ion batteries. Cost is a factor and I agree if you have a Class B for the life of the lithium ion batteries they might be cheaper in theory but I don't intend to find that out. I can afford the lithium ion batteries and the advantages they have mainly in much more amp hour capacity at a manageable space and weight that AGMs can't match. I can operate my Class B identically whether boondocking or on shore power almost indefinitely, without needing to or monitoring conserving power and without need for an Onan generator or propane. I find that priceless.

[GeorgeRa]

I am not sure a single answer for temperature limits for LiFePO4 is possible, it will vary by a manufacturer. One of LiFePO4 electrolytes is a composition of organic solvents like ethylene carbonate with freezing/melting temperature of 93-99°F, dimethyl carbonate 36-39°F plus lithium perchlorate salt and other additives. The composition of electrolytes will vary as a result of battery overall performance resulting in final electrolyte melting point. I am making a judgment call that melting temperature equates to batteries death temperature but there could be other reason causing battery death during charging, discharging and storage.

In addition, manufactures could have limited budgets to test batteries for low temperature limits so they scavenge for information and the market follows Goebbels law, many repeats settle the truth.

There are too many flavors of actual components of LiFePO4 battery and I doubt we will ever have a single answer for temperature limits. I don’t expect to have common answer like freezing temperature of sulfuric acid at various concentrations.

[booster]

I think it could be a long time before there is a settled answer on the temps, as it is beneficial for the manufacturers of lithium to not have it settled.


As the prices drop and the market gets more full of sellers and competitive, we could actually see more of them go back to the original claims from a few years ago when most said -40* was OK to store in. If they figure that a big majority of users will never be in those conditions, and if they are the batteries will still last long enough to get out of warranty or maybe just be worth the warranty costs for a few people. This may be Battleborn's current business model, and maybe even Trojan as they also say to float them which is now frowned on.

[markopolo]

With -4F commonly referenced as the minimum discharge temperature it just seems unlikely (to me) that catastrophe also occurs very near that point.

The Lithiumion Chargex brand even gives temperature performance specifications including -40F ( https://www.lithiumion-batteries.com...um-battery.php ) :

lithiumion temperature performance.JPG

It seem that the chemical reaction becomes basically inert as temperature is lowered beyond -40°F.

[booster]

Originally Posted by markopolo

With -4F commonly referenced as the minimum discharge temperature it just seems unlikely (to me) that catastrophe also occurs very near that point.

The Lithiumion Chargex brand even gives temperature performance specifications including -40F ( https://www.lithiumion-batteries.com...um-battery.php ) :

Attachment 11109

It seem that the chemical reaction becomes basically inert as temperature is lowered beyond -40°F.

I think that it is likely true that it not a cliff you go over but more of a sliding scale. Very similar to the shortening of life in AGMs by going to deeper discharges that doesn't happen suddenly at 50%. That Volta, even though different chemistry, went to the effort of listing shortening times for acceptable storage as temps got lower would back that up.



I also think that the -40* F and -4*F are really just points of that curve that was easy to remember in degrees C as it is completely unlikely it just happened to be at -20* and -40*. Probably in the right areas but certainly not a cliff.


The no charging point is probably similar which would be indicated by some like ARV recommending higher than the given point for normal use. The charging point is also probably more critical based on that point based on that.


The cold storage thing that keeps coming back to me is that with the battery off and stored without being charged or discharged except for very minor self discharge, there is extremely low chemical reaction going on at any temperature. At that point it starts to become more likely to me that there is some sort of mechanical issue happening like expansion, material separation, etc. I don't think wet cells actually get destroyed by the cold itself, but sure do when the expand from freezing as a comparison.


I suppose the lowered performance and slowly chemical reaction could also be involved if the drop in output at lower temps is not a result of a complete chemical shutdown, but only of part of it. If, based on nothing I have heard or seen, for instance, one part of battery like the anode, cathode, or electrolyte was still slightly active but the other parts shut down from the cold what damage could happen to the active part even though there was no visible thing going on? Or if there was still a bit of reaction at the interfaces but chemical migration had stopped so it was trapped at that interface? Sometimes I wish I was a chemist, but not very often



I can't recall ever seeing a detailed tech paper or research study that fully explained why the temp limits are there, but the reasons given by nearly everything we see specifically say things like damage and shortened life, so they must know something is going on with the cold.


It sure would be nice to see a real and detailed failure analysis of the issue based on a confirmed cold failure unit.

[Bud]

"I can't recall ever seeing a detailed tech paper or research study that fully explained "

booster, I'm wondering if maybe that took about 100 years in the lead acid world. Lithium?

Bud

[booster]

Originally Posted by Bud

"I can't recall ever seeing a detailed tech paper or research study that fully explained "

booster, I'm wondering if maybe that took about 100 years in the lead acid world. Lithium?

Bud

The research was probably there but hidden away at the manufacturers.


There probably was very little public information around until they started to have some problems and questions got asked.


We have seen the lithium recommendations for things other than temperature change over the last few years also. Things like charge profiles, discharge rates, charge rates, etc It is not like it is just a temp thing.


Of course we still see that in AGM and wet cells also, like the new final stage of a short burst of higher voltage/controlled amps.

[Bud]

Originally Posted by booster

The research was probably there but hidden away at the manufacturers.


There probably was very little public information around until they started to have some problems and questions got asked.


We have seen the lithium recommendations for things other than temperature change over the last few years also. Things like charge profiles, discharge rates, charge rates, etc It is not like it is just a temp thing.


Of course we still see that in AGM and wet cells also, like the new final stage of a short burst of higher voltage/controlled amps.

I have some respect for some of the manufacturers and some providers that when not sure, they won't lie to sell more. I am guessing that is one of the reasons for some of the 'evidence' (so called) that can vary seemingly 'too much'. Also I'm guessing that early on, earlier on the folks that were experimenting with various lithium stuff were in fact unsure of plenty and were reluctant to buy into their own stuff until ............... The evidence was less conflicting, confusing.............

If and when I purchase the next B or even small c, it will be Lithium A/C. Hey, if I destroy the batteries, I'll just buy more. But if I find I don't use/need a/c, it will still be lithium. That day Is here with few exceptions. booster, it is for you too, IF you were to start over with or without a/c. That is also a guess, but

Come to think of it booster, if starting another B or rv, what are your thoughts? What would work for the two of you? And no, you don't get to come up with some cool monster that you pull your Roadmaster with.

Bud

[booster]

Originally Posted by Bud

I have some respect for some of the manufacturers and some providers that when not sure, they won't lie to sell more. I am guessing that is one of the reasons for some of the 'evidence' (so called) that can vary seemingly 'too much'. Also I'm guessing that early on, earlier on the folks that were experimenting with various lithium stuff were in fact unsure of plenty and were reluctant to buy into their own stuff until ............... The evidence was less conflicting, confusing.............

If and when I purchase the next B or even small c, it will be Lithium A/C. Hey, if I destroy the batteries, I'll just buy more. But if I find I don't use/need a/c, it will still be lithium. That day Is here with few exceptions. booster, it is for you too, IF you were to start over with or without a/c. That is also a guess, but

Come to think of it booster, if starting another B or rv, what are your thoughts? What would work for the two of you? And no, you don't get to come up with some cool monster that you pull your Roadmaster with.

Bud

I agree on the some reputable lead acid manufacturers, with Trojan and Lifeline being pretty good example IMO.


I am quite certain I would do AGM again at this point as ours has been trouble free, doesn't need attention except for curiosity sake, and does all we need and more. No heaters or cutoff temps in the semi normal range of use. It would probably be higher voltage though, probably 36v. It would not be an integrated system on single control, though, I think. Independent charging is nice if one of the three sources dies as you are still functional.

The exception would be if we win the lottery and get a very high end unit with an integrated and very long warranty lithium setup, since we could afford to fly out a tech if the integration died and we lost most every function at once.

[kmessinger]

Originally Posted by scottfelt

Hi folks. Very new to all of this and don't even have a unit picked out and have never owned one. I have done some reading to educate myself. So, thinking long term value and flexibility, I can clearly see the argument for a lithium system. I do know they cost more up front. However, in the articles I've read, they are comparing the cost of a lithium battery (say, $1300) vs the cost of an AGM batter (say, $250). My problem is that when I look at new class B rv's, I see a $20-$25k premium to have these systems. Can somebody help me understand what else drives this cost? And, knowing how RV dealers and manufacturers inflate the cost of everything, what is a fair mark-up? Like, if I negotiate the cost of the coach without lithium and get it to price $x and then say, ok, I want that but add lithium, can I expect to get it for less than the $20-$25k? Thanks for all the help. I'm sure I will have more questions as I go down this process of deciding what to get.

The lithium system has many more components than the batteries. An extra alternator so you can charge the batteries with the engine, solar panels so you can charge without the engine, an inverter to change the 12volts to 110 volts, wires and gauges and labor.

The reason we went this way (2022 Travato on order with Pure 3 energy system) is NO generator. They are loud, have to be maintained and won't run everything like the air conditioner. Stealth - a generator is a dead give away someone is camping near by and irritating.

It is common to get a 20% discount off MSRP or even more but the electrical system is like an option for leather seats or color. When it is put all together as a package, your discount applies to the whole thing. Look at the total cost not the cost of each component.

This post, like anyone about lithium, got technical real fast. All I know is the little magic guys carry the electricity from any type battery but get real upset if they touch the ground.

[coss370]

I absolutely hate my generator. It is noisy, smelly and it vibrates like mad. I cant wait to do a full lithium swap to get rid of it or at least not use it.

[avanti]

Originally Posted by coss370

I absolutely hate my generator. It is noisy, smelly and it vibrates like mad. I cant wait to do a full lithium swap to get rid of it or at least not use it.

I hated mine, too, so I upgraded to 440 AH of AGM and a second engine alternator. No lithium necessary.

[MobileCabin]

Booster,

There are a number of engineering groups working on the cold impact on battery performance. As others mentioned the commercial entities probably keep a close hold on their work. On the other hand the academic engineering groups publish. For example (Preheating method of lithium-ion batteries in an electric vehicle, Zhiguo LEI (&), Chengning ZHANG, Junqiu LI, Guangchong FAN, Zhewei LIN, J. Mod. Power Syst. Clean Energy (2015) 3(2):289–296, DOI 10.1007/s40565-015-0115-1). This paper is several years old but it includes a summary of the causes of performance decrease with temperature for lithium batteries. Some of their later papers continue to look at better methods to preheat. Yes there are better ways than wrapping the battery case with a heater. Sandia Labs had a report on temperature impact on sealed lead acid batteries about 20 years ago. I may have a reference to it if needed.

As for current state of art, I assume there are many more technical papers out there. Some night when I can't sleep I may search them out.

Pat

[Hammernine]

We bought an older Road Trek 2008 200 popular. We wanted to boondock to avoid RV park charges when possible. We purchased a GoPower Elite system for about $3,000. I installed myself (challenging but not impossible) and we used AGM batteries at about $1,000 for 4. The GoPower system is programmable so we can switch to Lithium later without any additional hardware. Using Lithium is a better value in the long run than AGM. The decision driver is how often you use the RV. If you use it constantly the AGM's will last about 2 years, the lithium's about 10 years. So if you RV say 12 weekends a year don't bother with lithium's. If you are a road warrior than do it. When my AGM's die I will replace with Lithium's. We RV alot.

[Roadie1]

I have a 2020 Revel and added the RoamRig stage three lithium setup which includes a second alternator. It’s amazing! The stock system was pretty poor. Now we can run the ac all night off grid. No shore power or ginny needed.