Lithium Titanate

[pianotuna]

Hi All,

I got a quote on Lithium Titanate

"Max discharge rate is 10 C so 900 amps for 90 ah and 1200 amps for 120 ah

The 120 will be 30% more expensive than the 90.

Price for 90 ah is $1500 cad and for 120 ah $1900 Cad per battery. It’s not a regular battery, so needs to be custom made.

I’ll get feedback on dimensions."

Far too rich for my blood, since I wish to have 600 amp-hours.

Back to SiO2 for me.

[MEXICOWANDERER]

I have to raise my eyebrows at the cost of being liberated from the power post. Down here, RV campsites are getting out of hand with some unimproved beaches going for $15 U.S per day.
When I was piloting Quicksilver, the object was to find a beautiful palm lined beach and then do the best I could camping out. Solar panels did not exist so running a generator was the hot setup. With no one around masochistic noise limit was the only restriction.
Now Quicksilver is "permanently" ensconced near a beach. The days of free beach loafing are history. Some developed sites near Cancun are getting $100 night.
So leading all this up to an innocent question...

What do thousand dollar batteries buy you?

[pianotuna]

3 tons,

The issue with solar charging seems to be the capacity of the charge controllers. An 80 amp is $600 to $800 smackers. There are a few 100 amp controllers, but at least one of them is a "swindle" as it can't do 100 amps at 12 volts. So even a single LiFePo4 is going to exceed what solar can produce.

Suppose we take 14.6 as the "bulk" voltage. 80 x 14.6 = 1168 watts.

The same sort of limit happens with converters and inverter/chargers. Assuming 200 amp-hours of Li the power factor corrected Magnum maxes out at 127 amps. 127 x 14.6 = 1874 watts--so it would exceed what a 15 amp circuit could handle. So, I would have to scale back the voltage to 14.1. Or if I wanted the 14.6 volts, I would have to limit the Magnum to 123 amps.

So faster charging is not really going to be that much faster, especially with a large bank.

I would not think any serious boondocker would have less than 2 to 3 hundred amp-hours.

So the only "real" chemical advantage of the LI is that they don't sulphate.

The "physical" advantage is that they weigh a lot less than flooded batteries.

I want 600 amp-hours of SiO2. They would charge at .25 C or 150 amps. I have no way to provide them with 150 amps.

I know that BFL13 noted tapering on SiO2--but I do not know if he was charging at 14.6 volts. They, too, do not suffer from sulphation. Their ability to be used at -40 is needful for me--and I won't have to jump through hoops to prevent alternator damage, nor use dc to DC charge devices (though that would be a benefit, given my business use where I might well drive for 5 hours in a day).

I just today found out that SiO2 are lighter than flooded batteries of similar capacity. They are a bit cheaper than LiFePo4 from places such as Battleborn or Lion.

If you "roll your own" LiFePo4 then we get to about $368 USD. The folks at Lac La Biche quoted $313 (usd) for a drop in 12 volt 100 amp-hour with BMS.

[BFL13]

3 tons wrote:
As I pointed out, Expion claims 3 x faster.. I have no desire whatsoever to conduct my own empirical timed test to challenge their claim as I’m quite happy to leave that level of parsing to someone who’s doggedly interested - lol... it’s plenty enough for me just to have optimized solar harvest recover times to much faster than with my former equivalent capacity GC’s - from ‘back-to-back’ experience Expion’s claim of 3 x faster recovery than with FWC seems at least somewhat realistic to me (+ or -), thus not really worth disputing Expion’s claim...JMHO,

3 tons

IMO all they are doing is saying you can charge the LFP at 1C but the FLA's at only 0.3C so that to them means "3 x faster"--which is total hogwash when you define "faster" in terms of AH restoration over time unless you can provide the scenario in detail, for an RV set-up.

You did however do an empirical timed test to prove that somehow your solar charging is "much faster" with LFP than with your previous GCs.

It would be interesting to see your figures that show that, and with that, what you mean by "faster".

[3_tons]

As I pointed out, Expion claims 3 x faster.. I have no desire whatsoever to conduct my own empirical timed test to challenge their claim as I’m quite happy to leave that level of parsing to someone who’s doggedly interested - lol... it’s plenty enough for me just to have optimized solar harvest recover times to much faster than with my former equivalent capacity GC’s - from ‘back-to-back’ experience Expion’s claim of 3 x faster recovery than with FWC seems at least somewhat realistic to me (+ or -), thus not really worth disputing Expion’s claim...JMHO,

3 tons

[BFL13]

3 tons wrote:
I’ve never heard of them, so I looked it up:

https://en.wikipedia.org/wiki/Lithium-titanate_battery

I’ll be sticking with LiFePo4’s because (per expion) they charge about 3x faster than flooded wet cell batteries which seems to strike a good balance between safety, density and charge rate - JMO

3 tons

What does "3x faster mean"? 1/3 the time for restoring the same number of AH? 3 x the AH in the same time?

It takes about 2 1/2 hrs (150 min) to restore 184 AH doing a 50-90 on four 6s of 460AH with a 75 amp charger set to 14.8v, run from a 2200w gen (maxing out the gen for VA)--BTDT.

So if it means you can do that in 1/3 the time with LFP, that means in 150/3 = 50 minutes to do 184AH. So you would be charging at 221 amps for that 50 minutes. How can you do that in an RV?

At 1C, that would mean 221AH worth of LFP in the bank. At .5C that would be with 442AH of LFP.

You can carry the batteries, but howinheck can you charge at 221 amps with what size generator to run a 221 amp charger?

So what value to an RVer is the claim of "3 times faster" charging? How would you set up your RV to be able to charge "3 times faster"? I can't understand it.

[3_tons]

I’ve never heard of them, so I looked it up:

https://en.wikipedia.org/wiki/Lithium-titanate_battery

I’ll be sticking with LiFePo4’s because (per expion) they charge about 3x faster than flooded wet cell batteries which seems to strike a good balance between safety, density and charge rate - JMO

3 tons

[pianotuna]

Steve,

It is a concern if you store at -40. How do you get the "living space" warm without a usable battery bank?

the company I was writing to has a 100 amp-hour LiFeP04 with BMS drop in for $400 Canadian. Their store is at Lac La Biche Alberta

[StirCrazy]

pianotuna wrote:


The one I sourced was a drop in replacement with a BMS. Just extremely costly.

really, the last article I had read said they were 5 to 10 years off from being good enough for mass production and use. neat.

Steve

I was flipping back and forth between a few types but now that LFP has dropped so low and with no offgasing whats so ever you can mount them inside the condistioned space, so temp isnt a concern at all anymore. buck/usable ah they are now the cheepest battery on the market and if you solve the cold charging issue by puting them inside the camper there is no downside to them.

Steve

[Gjac]

Lwiddis wrote:
We can always depend on Don to keep us current on RV batteries issues.

Yes we can. Don have you looked at Nickle Hydride batteries yet? I have them in my Hybrid car and they work best and have tere longest life from 20-80% SOC which sounds just right for dry camping. They never fully charge unless there is a long down hill, and are cheaper than LI batteries for cars, but don't know if they can be made into a 12v battery? Have you investigated these yet?

[pianotuna]

bdosborn wrote:
Have you thought about building your own system? It's easy with a little research. LTO is an awkward cell to work with due to the nominal voltage of 2.4V. Setting up for a 12V nominal systems means a 12V or 14.4V pile. These are are weird voltages to charge and run appliances on, you'll need a programmable charger and probably a dc-dc converter. 24V nominal is workable but the easily sourced cell(Yinglang)is only 40 A-H. To get to 600a-h@24V, you'11 need a 10S16P pile, or 160 cells. At $43.5/cell bulk price on Aliexpress, that would be $6,960 for a roll-your-own system.

Assuming you originally wanted 600A-H@12v, you would have the same capacity with 300A-H@24V. Then the cost is $3,480.

The tough part is finding chargers and a BMS for the LTO cells. They're probably out there (never looked) but LiFePO4 equipment is so much easier to find.

The one I sourced was a drop in replacement with a BMS. Just extremely costly.

[bdosborn]

Have you thought about building your own system? It's easy with a little research. LTO is an awkward cell to work with due to the nominal voltage of 2.4V. Setting up for a 12V nominal systems means a 12V or 14.4V pile. These are are weird voltages to charge and run appliances on, you'll need a programmable charger and probably a dc-dc converter. 24V nominal is workable but the easily sourced cell(Yinglang)is only 40 A-H. To get to 600a-h@24V, you'11 need a 10S16P pile, or 160 cells. At $43.5/cell bulk price on Aliexpress, that would be $6,960 for a roll-your-own system.

Assuming you originally wanted 600A-H@12v, you would have the same capacity with 300A-H@24V. Then the cost is $3,480.

The tough part is finding chargers and a BMS for the LTO cells. They're probably out there (never looked) but LiFePO4 equipment is so much easier to find.

[pianotuna]

time2roll wrote:
How does LT perform in the cold? Always going to be more $$$ until they standardize production and have some in stock.

LT are good to -40 which is impressive. But at 1900 Cdn for 100 amp-hours.....

They are able to do 10000 cycles, so in the long run they would be slightly cheaper than SiO2. But--I'll not even have enough cycles left in ME to outlast 1500 cycles as a weekend warrior.

The LT have a lower storage density than LiFePo4.

BTW the company I was writing to has a 100 amp-hour LiFeP04 for $400 Canadian. Their store is at Lac La Biche Alberta. Which is one heck of a good price.

I did ask them about SiO2 and that seemed to fall on deaf ears.

[Reisender]

Lwiddis wrote:
We can always depend on Don to keep us current on RV batteries issues.

But ya know, I kinda like that. I’m pretty sure if we ever get thru that part of Saskatchewan we’ll be looking him up and inviting him to a rack of ribs and a bottle of wine. I’m fairly certain it will be an interesting dinner. :).

[time2roll]

How does LT perform in the cold? Always going to be more $$$ until they standardize production and have some in stock.

[RickLight]

pianotuna,

you might look at this
https://lionenergy.com/products/lion-safari-ut-1300#winter