New Battery Technology

[T1 Terry]

Originally Posted by T1 Terry

Then you are the man to talk to .... what BMS system did you use to monitor cell voltages and trigger load cut and charge cut? What voltages do you use as the safe upper and lower voltages? Getting proper information about the "Safe for long cycle life" about these cells is hard to find, just like LFP and LYP cells, the manufacturers cell voltage extremes are not the same as extended cycle life extremes but rather maximum capacity extremes and cycle life be buggered ....

What cell balancing method do you use? Because the voltages are so low the differential between a high cell and a low cell doesn't work well with capacity shifting type balancing and the crude method of turning capacity into heat requires a lot of secondary wiring and cooling that would be great to avoid, as well as the energy wastefulness of those type of systems.

With big charging currents comes very rapid cell voltage rise so charge stop and quick energy movement would be the key to rapid charging without cell destruction, so this is a problem that needs to be addressed to make this chemistry viable for the future.

The long term aim has to be cell cycle life extension rather than the acceptance of lost cycle life from the norm if these cells are to be the basis of the house battery and traction battery all in one solution that is already becoming part of how energy storage is used here in Australia ..... plug in the EV to the house and solar and it becomes the main energy storage/supply point with a much smaller dedicated house battery to keep the system functioning while the EV is off doing its primary function.

Such a battery could revolutionise the whole cruising seen, both on the water and on the land, the same battery powers the house and the drive, no more fuel requirements accept for the occasional recharge if the solar/current/wind generation wasn't sufficient.

T1 Terry

Wow, long time since I've been here. I see it's been 18 mths since I asked the ëxpert" Captain Rivet who told us
"I installed 7 cars and 4 boats with LTO so I know what i am talking about compared to 99% here who sitting on the sofa and repeat what they read somewhere." but he seems to have missed this request for information that he seems to believe he has because he has mastered using LTO cells.

I'm in the process of building an 84 cell in series 55Ah LTO battery for my Gen 2 Prius ('06) to replace the 6Ah NiMh traction battery.
I hope the good captain will come back with some information, otherwise I'll have to build my own cell balancing system and high cell/low cell cut BMS.
To build a 12v nom. LTO battery you will require 5 cells in series, so halfway between an LFP battery and a lead acid battery, but the available current without substantial voltage drop is something not yet seen in any other chemistry, yet is as safe as any battery can be, and that includes super capacitors .....

T1 Terry

[rgleason]

Hope you find a good solution.

I'm in the process of building an 84 cell in series 55Ah LTO battery for my Gen 2 Prius ('06) to replace the 6Ah NiMh traction battery.

How much space is this going to use?
The prime prius reduces the trunk with enough battery for 35 miles, and reduces the Prius utility.

[CaptainRivet]

Originally Posted by T1 Terry

Wow, long time since I've been here. I see it's been 18 mths since I asked the ëxpert" Captain Rivet who told us
"I installed 7 cars and 4 boats with LTO so I know what i am talking about compared to 99% here who sitting on the sofa and repeat what they read somewhere." but he seems to have missed this request for information that he seems to believe he has because he has mastered using LTO cells.

I'm in the process of building an 84 cell in series 55Ah LTO battery for my Gen 2 Prius ('06) to replace the 6Ah NiMh traction battery.
I hope the good captain will come back with some information, otherwise I'll have to build my own cell balancing system and high cell/low cell cut BMS.
To build a 12v nom. LTO battery you will require 5 cells in series, so halfway between an LFP battery and a lead acid battery, but the available current without substantial voltage drop is something not yet seen in any other chemistry, yet is as safe as any battery can be, and that includes super capacitors .....

T1 Terry

HI Terry,


sorry I really missed that request...


I am by far not the LTO expert but I have some extended experience with them.
but only with the Yinlong LTO cells which come offically come in 30, 40 and 55AH. I only use the 30AH and 40AH cells as the 55AH have production problems and should be avoided.

These cells are originally made for Korean public transport where the buses get charged via induction with extrem high amps for short amount of time standing at the bus stop. no eperience with other LTO cells and if they behave different or similar.



they have 30000cylces so over 50years lifespan means the way we used them is to use them safely but with minimum efforts possible, means if they loose 5000 cycles of their lifespan because we simply charged them with the lead charging profile of the old car alternator we didn't care. And oh boy we tortured these cells really badly and the abuse they can take is from another world.



The yinglong cells have an offical range of 1,52V till 2,7V per cell where you can officially operate them without damage.
But if you put them in series you shouldn't go below 2,0V and above 2.55V if you wanna keep the 30000cycles. If you exceed the range a warning is enough, if you are not going out of the range too extrem (like 5V or 40V) for several hours or even a day normally nothing happens.

The majority of the capacity is between 2,2V and 2,45V (depending on C rate and temp), I used 2,05V start charge till 2,52V end of charge, LVC 1,9V and HVC 2,6V

Which means you need 6 cells for a nominal 12V battery pack.

the 2,52V as HVC is to protect all 12V equipment as this is rated till 16,0V and with the voltage drop due to cables from the 16,2V at the battery nothing will get more then 16,0V. Like this you charge the LTO to approx 92-94% of its capacity. LTO doesn't care if its never full or totally empty.
the only thing i done before installing is to top balance them to 2,65V which is the exact same proecure as with Lifepo4, then I build the battery pack and discharge it to 2,52V.


As I often said for 6 cells of LTO in series you don't need a BMS and I only used once a BMS for it.



for the cars, we replaced the starter battery with LTO and the LTO also delivered the power for the massive car stereo system:
mostly 6x40AH cells in 1P6S config replaced the starter, frequently we used 2P6S with 30A or 40AH cells. 7lV8 engine of the corvette z06 was no problem to frequently start with a 40AH LTO.

Drop in like they are replacing the lead starter, no BMS and no adaption to alternator. The only thing a voltage monitor so you see the voltage of the pack. If there was a selection in the cars ECU for charging we used the biggest AGM that can be selected. NO HVC or LVC cut off. Mostly the LTOs where fully charged with a big external power supply to 16V, so the alternator had to just top off. And at the shows or meets as support a big 220V power supply put to 15V. monthly till quaterly we dismantled the battery pack and did a top balance but that was hardly needed. Whats the worst that can happen??? pack empty and you jump start with another car with LTO but only if you have min a 2/0 gauge jumper cable (guess how we found out) or you put it on the power supply till full again.

Worked like a charm, my buddy Z06 is now in the 5th year with the LTO and still going strong.



boats: only 12V means 6S too. In all cases we replaced the starter and house battery with one battery pack that does both.
3 boats I put in 4P6S battery pack means 13,8V 160AH replacing 55-90AH starter and 250-560AH lead house. No BMS/no balancer and the LVC and HVC is done by 2 Victron BMV 712 battery monitors with a) audio warning at 12,4V/15,8V and 12V/16.2V b) real cut off by blue systems relais at 11,4V and 16,5V. Alternator adapted with an external regulator VMR 200 from nordkyn, Victron solar MPPT and Multiplus 12/3500 shore charger/inverter adjusted to 12V/16,2 (use LI Profile and adapt in expert mode).
1 boat my 40ft longkeeler ketch with 18m bowtruster: i replaced 140AH hybrid lead starter/house and 420AH hybrid lead house (the bowtruster which needed approx 600A and 900A peak was connected to the house) was replaced by 8P6S LTO 40AH cells so 320AH all in one bank (starter/house/bowtruster). First same config as above with 3P6S boats, then I added a 1P6S LTO as starter which is loaded via a cytrix battery combiner.
I also found and installed the Electrodacus BMS which took control over the house/bowtruster pack and all Victron equipment incl. LCV and HVC but still the one BMV 712 does a 2nd LVC at 11,0V just in case and the 2nd BMV712 takes care about the starter.
Elektrodacus BMS: Start charge 2,05V/End of charge 2,52/LVC 1,85V/HVC 2,6V, Temp charge stop low -50C high +70 degree celsius

Eletrodacus BMS has a passive 2A balancer and that was enough.

I mainly used Electrodacus because its a great monitoring tool, steers all the victron gear I anyhow had already and is cheaper then another 2 BMV 712 which I would have needed when adding a seperate starter LTO.


With 6S=12V and the C-rates you frequently draw or charge longer then 1S are below 1C which is a very light load/charge so they don't drift apart.

[CaptainRivet]

Originally Posted by T1 Terry

Wow, long time since I've been here. I see it's been 18 mths since I asked the ëxpert" Captain Rivet who told us
"I installed 7 cars and 4 boats with LTO so I know what i am talking about compared to 99% here who sitting on the sofa and repeat what they read somewhere." but he seems to have missed this request for information that he seems to believe he has because he has mastered using LTO cells.

I'm in the process of building an 84 cell in series 55Ah LTO battery for my Gen 2 Prius ('06) to replace the 6Ah NiMh traction battery.
I hope the good captain will come back with some information, otherwise I'll have to build my own cell balancing system and high cell/low cell cut BMS.
To build a 12v nom. LTO battery you will require 5 cells in series, so halfway between an LFP battery and a lead acid battery, but the available current without substantial voltage drop is something not yet seen in any other chemistry, yet is as safe as any battery can be, and that includes super capacitors .....

T1 Terry

part 2:


but if you use more then 6cells in series you need a balancer and maybe a BMS. And the more you put in series the more beefy your balancer must be.


24V:

I lately helped a friend putting 2P11S 24V/80AH LTO starter battery in his mono. I used no BMS but 11 of this modular active balancer
https://www.lto-store.de/home/1S-QNB...cer-p275130257


Mono has a 5kw starter so the battery regularly gets 4 or 5C discharge. We first tried without balancer but the pack started to differ after 1 month already, with the balancers everything stays balanced.



48V:
my friends have an NPO in austria and built the "Titan one", thats a 22S6P 48V LTO house storage pack built from 88 pieces 40AH LTO yinlong cells.
They have their own BMS with first passive and now active balancers

https://zukunftswerkstatt-verkehr.at/titanone.html
Without the balancers the bank will be out of balance in 4 weeks latest.
Maybe contact them, I was told the BMS is modular so maybe they can help you here.
These are the real LTO pros...

with 84 cells in series i am sure you need to build your own BMS with balancers.

[T1 Terry]

Originally Posted by rgleason

Hope you find a good solution.

I'm in the process of building an 84 cell in series 55Ah LTO battery for my Gen 2 Prius ('06) to replace the 6Ah NiMh traction battery.

How much space is this going to use?
The prime prius reduces the trunk with enough battery for 35 miles, and reduces the Prius utility.

42 cells go where the original traction battery was and the other 42 cells go in a box that replaces the spare wheel well. The muffler needs to be moved over a bit and the support for the jack point needs a bit of modification but braces well against the back of the box that houses the 42 cells.
The original plastic tray still fits, so the limp home spare wheel fits in there along with the jack and fast charging cables ..... well, they will when I finish it
When I'm a bit further through, I'dd add a link if you want, but there is a thread on Prius Chat in the Gen 2 section https://priuschat.com/threads/06-pri...-cells.234677/

T1 Terry

[T1 Terry]

Thank you Captain Rivet. I use 6 cells in series for each 2 module pack that made up the original NiMh Prius traction battery. They monitor the 28 module pack in 2 module bundles, so a total of 14 module packs monitored, so I needed to match that. The 2v per cell as a low end cut works well with the Prius and generally the upper regen charge cut is 8.5v per module or 17v per monitored pr, so 2.85v per cell fits in well with the original Prius system.
I hope you are wrong about the Yinlong 55Ah cells, I have already killed 4 of them when an all thread 5mm rod length buckled and shorted 4 cell cases together, they don't vaporise the electrolyte the way the LFP/LYP cells do, they pop the burst plug and simply empty out the electrolyte, so I'll be momitoring the cell temps and voltages carefully.
I did find 5 amp balancers for 16 cells, not cheap but cheaper than destroying the battery pack.

If this works as well as I'm hoping, electric propulsion could really take off, the Prius electric transaxle produces 80kw on its own so an 84 cell LTO battery would drive it, battery capacity would dictate for how long, but recharging is incredibly fast, so a short run from a genset would refill it if the solar, wind and water current generators didn't. Forget about steaming for a long distance if a crew member gets sick or injured, call the rescue people for help, they can get there a lot quicker anyway .....

T1 Terry

[goboatingnow]

Isn’t LTO only available in 18650 format. I haven’t seen pouch or prismatic LTO ( yet )

[T1 Terry]

Originally Posted by goboatingnow

Isn’t LTO only available in 18650 format. I haven’t seen pouch or prismatic LTO ( yet )

OSN Power, talk to Dinah, tell her Terry @ T1 Lithium said she was the person to talk to to get the best deals and 100% top quality cells. There are a lot of formats now for LTO cells and Yinlong make some of the best available, just be careful about getting caught with B grade or even C grade cells.
You will see the 45Ah cells come in 40Ah, 35Ah and even 30Ah, yet all the same format, this is because only the A grade cells produce the 45Ah on a consistent basis after multiple 100% high rate discharges, the ones that don't meet the A grade specs, rather than being sold as B grade etc, OSN sell them at the repeatable capacity rating so they can keep their good name.

T1 Terry

[rgleason]

Thanks TI Terry and Capt Rivit for posting your interesting projects. We should learn more about LTO. With 6 cells needed for 12v. that eliminates many BMS. but you arent using a BMS in most cases. Why?

[T1 Terry]

Originally Posted by rgleason

Thanks TI Terry and Capt Rivit for posting your interesting projects. We should learn more about LTO. With 6 cells needed for 12v. that eliminates many BMS. but you arent using a BMS in most cases. Why?

I'm certainly using a BMS that watches cell voltage and puts out a warning if a cell goes high or low and then battery isolation if that warning is ignored.
I will also be using active cell balancing to keep all the cells together and the Prius has balancing between each 6 cells as well and monitors the high and low voltage and adjusts its functions accordingly.

T1 Terry

EDIT: I am only using 6 cells in series because I need to cater for the voltage range two of the original Prius modules would, 10v to 17v, 1.66v to 2.83v per LTO cell.
To match the range a 12v nom. battery normally operates at between 10v and 14.4v, each LTO cell would be operating between 2v and 2.88v border line high for the LTO cell, but the 14.4v is only the peak charging voltage (some call it bulk, others absorption, but the latter is a lead acid requirement that also requires a time held at that voltage) that shouldn't be seen at the cells for more than a minute or so, before dropping back to float voltage and that could be as high as 14.2v.

There are a number of companies now building BMS systems designed to operate with LTO cell voltages like the Daly brand and the Zeva gear that you can build yourself, or the units that are simply cell based and interconnect so how ever many cells you have, you can have a module for each.

[rgleason]

New Electrolyte https://www.solidpowerbattery.com/


https://www.solidpowerbattery.com/electrolytes/

[Dragon701]

Hi Rob,

With the amount of research you have done on new technologies, this article might be repetitious. Nevertheless, it has some great information that covers the "waterfront" (so to speak) well.

https://news.stanford.edu/2022/08/11/battery-technology-research-stanford/#:~:text=Liquid-metal%2C%20high-voltage,affordable%20storage%20of%20renewable%20po wer

Good luck with the project. It will be interesting to hear the outcome.

[Loredo]

I have replaced the optima red top batteries of both the bow & stern thruster on my boat with LTO.
Background, the BT is a 10KW unit. 100AH @ 24V brand new optima red tops just could not handle the power demand. After a burst of 5 seconds their voltage sagged below 10.5 V. After a 10 second burst they were down to 9ish V. The stern thruster is only 6.5KW but the scenario wasn't much better - +/- the same. It was more or less like, "OK let's get this docking right on the first attempt because there ain't much thrust left for a second one".



BT 12S2P 40AH grade A LTO's.
ST 12S 40AH also grade A.

I'll start saying, the difference between AGM and LTO is night and day.
Of course the voltage sags also with the LTO's but not as much and most importantly only after much longer bursts. (Who needs really long burst from the BT or ST anyway?) The increased thrust due to the higher voltage that's maintained by the LTO's make both thruster much more powerful than with the optima(s).



What attracted me in the LTO's was not needing to change a dime in the charge sources. Plug in and forget... THAT works.
Secondly, a lot of reading later convinced me that no balancing and no BMS would be needed. Well, that's not so true!

The cells got out of balance after only a couple, not even too long, burst.
Out of balance badly! I ended up installing active balancing modules from

Heltec. It's now since February that the system works flawless and honestly I don't feel the need to install a BMS.
No BMS because... where would I find one that could work with a 10KW motor? Then, that last thing I'd want is the BMS shutting down the batteries while I might badly need the thruster. Clear, if I discharge the LTO's too deep too often their life will be reduced. Yet, in this case application even if I get only a 10% of their claimed lifespan, they'll outlast

me, the thrusters, the boat!


Another interesting feature of them LTO's is that their SOC can be predicted perfectly from their voltage. Under a constant load, the sinking voltage is linear with the remaining capacity



I would use LTO also for the house bank but... low energy density and price are holding me back. Even if money was no problem, space on any boat is very scarce and rare.

[T1 Terry]

I would still have a cell monitor to get a warning if a cell is suffering under load, it will give you a warning that the cell needs some attention. It's not always a crook cell, sometimes it's bad connection, left unattended and the heat generated with destroy a perfectly good cell, or even just melt the terminal off and rendering the cell and the battery useless until the problem is sorted.

A simply 7 wire JST-XH wired plug from evilbay or the local hobby store and a cell voltage checker will do the job and very cheap insurance to avoid an unexpected failure

T1 Terry

[goboatingnow]

Yes LTO , certainly if prices fall , are the batteries for boats.