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More LTO cells ~3.5ah

Posted: Mar 06 2018 4:20pm
by Inwo
Don't know condition, new or tested, or quantity.
Any interest? Too small for me.
Only samples so far. I could arrange shipping a single sample if someone wants a head-start.
Should be at least 500pcs available.
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Re: More LTO cells ~3.5ah

Posted: Mar 06 2018 6:31pm
by spinningmagnets
Needs banana for scale. I bought six of the 11Ah foil pouches. And I thought five of them would be good for a 12V pack. The seller I got them from insisted they worked better as 6S, so I will try that. It's an odd voltage. 2.4V nominal, but...if you look at the discharge curve graphs, the useful range seems to be 2.2V to 2.6V.

They can be charged up to 2.8V, and the listed LVC is 1.7V, however, one of the interesting features is that "supposedly" they can be discharged to zero, without suffering any harm.

Very high C-rate when charging and discharging.

Can operate in unusually cold weather much better than the more common chemistries.

Very high cycle life, 7,000 cycles seems to be a common spec...

Xxxxxxxxxxxxxxxxxxxxx

One of the uses is as a feeder for a 12V capacitor bank, being used to start a car. There are many videos of supercapacitors (five 3.0V, or six 2.7V) that easily start a car in extremely cold weather (where lead acid, and even lithium will struggle with voltage sag).

Also, the capacitors are not hurt by very hot weather (lead-acid batteries in Phoenix in the summer). A properly-specced supercap bank can be charged directly by the cars alternator system.

Capacitors should last the life of the vehicle, but...their one huge flaw is that they slowly drain down over time.

There are two strategies to fix that. One way is to use huge supercapacitors that will last a couple weeks before draining, or...use a small supercapacitor bank that is coupled with a hand-sized 12V battery. ($60-ish for the caps, Google 3.0V Amperics)

https://www.amperics.com/product/am12v250a/

Charge the capacitor bank through a 1/2 ohm resistor, then start the car with the supercaps. Since LTO chemistry performs well in the cold, it could still be kept in the car. It's long term life-cycle is a great match for supercaps.

Once you are driving, recharge the LTO pack from the 12V utility socket. The small 12V pack can also be a sweet portable phone or laptop auxiliary battery bank.

Re: More LTO cells ~3.5ah

Posted: Mar 06 2018 10:32pm
by Inwo
A little wider than the 11ah.
6s is best for automotive use. 16.5 volt max should never be reached with alternator.
2p will start a v8. 3p for racing motors.
I'm using 2p on my diesel mower.
These small cells are dead. Mike is testing them hard. From dead to full in 8 minutes.
I had a bunch of these small ones before, but gave them away with another sale.

Re: More LTO cells ~3.5ah

Posted: Mar 06 2018 11:16pm
by spinningmagnets
How much for 12 of these?

_________LVC___useful range___max charge
Per cell__1.7V____2.2V---2.6V___2.8V
____5S___8.5V__11.0V--13.0V__14.0V
____6S__10.2V__13.2V--15.6V__16.8V

Re: More LTO cells ~3.5ah

Posted: Mar 06 2018 11:40pm
by Inwo
$100 for 12pcs 11ah conus Friends and family. 😉
12 are easy for me to ship.

Re: More LTO cells ~3.5ah

Posted: Mar 07 2018 5:08pm
by themelon
I'll take a sample to try out if you are still offering.

Re: More LTO cells ~3.5ah

Posted: Mar 07 2018 5:17pm
by spinningmagnets
I just recieved six of the 11Ah pouches, very well packed and rapid shipping. Depending on how the experiments go, I may buy a $h!t-ton of these while they are available. If they work for the 12V "suitcases", they should last my lifetime...

Just bought a $40 Harbor Freight Tool (HFT) suitcase that is a Pelican clone. Apache brand, Model 3800, $40.

Re: More LTO cells ~3.5ah

Posted: Mar 07 2018 11:38pm
by Inwo
themelon wrote:
Mar 07 2018 5:08pm
I'll take a sample to try out if you are still offering.
My partner is on vacation for a couple weeks.
He has test charged a completely dead cell @25a rate.
Full capacity.

Re: More LTO cells ~3.5ah

Posted: Mar 08 2018 8:18am
by themelon
Inwo wrote:
Mar 07 2018 11:38pm
themelon wrote:
Mar 07 2018 5:08pm
I'll take a sample to try out if you are still offering.
My partner is on vacation for a couple weeks.
He has test charged a completely dead cell @25a rate.
Full capacity.
I have come up with a number of uses for them and would likely not have a problem going through more than 500 cells pretty quickly. Can you post basic dimensions while your partner is out? PM me and we can work something out. I am genuinely interested.

Re: More LTO cells ~3.5ah

Posted: Mar 08 2018 1:20pm
by Inwo
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Re: More LTO cells ~3.5ah

Posted: Mar 15 2018 8:53am
by Vanarian
Inwo wrote:
Mar 08 2018 1:20pm
8.4kwlto.jpg
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Can you please detail what we see ? packs are roughly 70x47mm and 100x47mm ? What is the thickness of both, what is the weight / pouch ? Which specs for both size ?

At 1.50$ / piece it looks pretty affordable ; is it 2.4v 3.5Ah ? What is the max discharge per cell (I see you tested up to 25A) ?

If I calculate roughly 60 cells = 90USD + shipping ? 20S3P, 48V 10.5Ah ?

Re: More LTO cells ~3.5ah

Posted: Mar 15 2018 11:11am
by cal3thousand
themelon wrote:
Mar 08 2018 8:18am
Inwo wrote:
Mar 07 2018 11:38pm
themelon wrote:
Mar 07 2018 5:08pm
I'll take a sample to try out if you are still offering.
My partner is on vacation for a couple weeks.
He has test charged a completely dead cell @25a rate.
Full capacity.
I have come up with a number of uses for them and would likely not have a problem going through more than 500 cells pretty quickly. Can you post basic dimensions while your partner is out? PM me and we can work something out. I am genuinely interested.
That's a lot of cells. How do you plan on arranging/connecting cells?

Re: More LTO cells ~3.5ah

Posted: Mar 15 2018 3:21pm
by themelon
cal3thousand wrote:
Mar 15 2018 11:11am
themelon wrote:
Mar 08 2018 8:18am
Inwo wrote:
Mar 07 2018 11:38pm
themelon wrote:
Mar 07 2018 5:08pm
I'll take a sample to try out if you are still offering.
My partner is on vacation for a couple weeks.
He has test charged a completely dead cell @25a rate.
Full capacity.
I have come up with a number of uses for them and would likely not have a problem going through more than 500 cells pretty quickly. Can you post basic dimensions while your partner is out? PM me and we can work something out. I am genuinely interested.
That's a lot of cells. How do you plan on arranging/connecting cells?
I'll be replacing Lead Acid in allot of places so 6S and anywhere between 3P and 6P. Connecting, have not quite figured that one out yet but I have some ideas.

Re: More LTO cells ~3.5ah

Posted: Apr 11 2018 5:44pm
by cal3thousand
I would like to start using LTO in more applications in the future, based on what you've been sharing. Thanks for supplying these.

So to that end, I think I should start with a batch of these smaller pouches and see what I can make for fun and figure out how to build these things.

I'll take a dozen of these packs... PM sent

Re: More LTO cells ~3.5ah

Posted: Apr 11 2018 6:16pm
by Inwo
Thanks, I'll see what I can do. They are available now. Can't make good on the price until I take delivery of 1,000 pieces.

Re: More LTO cells ~3.5ah

Posted: Apr 12 2018 5:01pm
by coleasterling
So those at 3.5ah look much bigger than the 11ah ones? Any idea on the current capability? Hopefully super high? I have a bunch of the 11ah ones I've been wanting to use, but the current specs aren't high enough to make me use them over my LFP cells.

Re: More LTO cells ~3.5ah

Posted: Apr 12 2018 5:30pm
by Inwo
No, they are unknown.
The 11ah are great. I tested a 2p6s to 350a.
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Re: More LTO cells ~3.5ah

Posted: Apr 18 2018 10:55am
by coleasterling
Any chance you could do some quick DCIR measurements on the 3.5's? I'd need far higher specific power than the 11ah's to warrant purchasing them.

Re: More LTO cells ~3.5ah

Posted: Apr 18 2018 11:30am
by Inwo
Still don't have my hands on them.
Drop shipped some samples to a member. He may check in and report.
Had some a year ago from Kokam or Altairnano and was not impressed. I gave them away with another big order.
They seem near as heavy as the 11ah.
Once I do get them, price will reflect condition. Hope to get a report soon.
The warehouse will send 12pcs for $50.
Hope to do better when my pallet comes in, but it's a way to do some testing.

Re: More LTO cells ~3.5ah

Posted: May 03 2018 10:02am
by Inwo
Mine were shipped to Florida warehouse by mistake.
Now there's a middle man.
PM me for info, but he is at $2 minimum. More for small orders.
Sorry for the trouble. It will only add to the cost if I have them shipped to Mn. :(

Re: More LTO cells ~3.5ah

Posted: Aug 09 2019 8:43am
by Survivor694
Any of the 3.5 ah still available ?