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48V LTO Off Grid system
#11
I'm considering doing something similar - importing LTO or Lifepo4 batteries from China to Australia.

How are the LTO batteries going for you? Most companies seem to sell both, but Lifepo4 are cheaper. The 10000+ cycles of LTO is appealing, but I don't really plan to be still using this in 30 years, so I'm thinking Lifepo4.

Am I missing anything? Are LTO more likely to be legitimate?
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#12
Unfortunately there is no straight answer, it's still a horses for courses situation.

weight per watthour LiIon, LiPo, LFP/LiFePo4 are a superior battery than LTO which are physically larger and heavier at comparable capacities, so if you are limited on weight or physical size, like an electric vehicle, LTO are probably not suitable.

Where LTO shine is their long life expectancy as well as tolerance to over/under charging.

LTO cells can be discharged all the way down to 0 volts and recharged without damage, they can be overcharged, within reason, without exploding or suffering damage. I have had 0v cells that recharge happily and hold charge, I have had cells I accidentally over charged to 3.5v that stabilised back to 2.65v and continue as normal.

LTO are very safe with no off-gassing or oozing or thermal runaway. Search Youtube for "LTO safety test"

A 5 cell LTO pack is a drop in replacement for a 12v Lead Acid battery with equivalent charge and float voltages.

You still need a BMS, however off the shelf systems designed for super caps will work with LTO calls.

We have just finished building our 48v pack, each block is 8 parallel 30AH cells, 20 blocks in series give 48v 240AH, 11.5kWh:
[Image: NCq6vK7RC5WlI2GZiUjB_29qmfbhgRgjGz0eW9aF...6-h1009-no]

Importing in to Australia has been fairly easy, just count on spending at least half of the cell price in freight, don't forget the GST, customs charges and exchange rate on top.
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#13
You make some good points. I think I'll try ordering a few to test out - you got yours from OSN right? Do you know if anyone has tested out the ones from Kylin or other cheaper suppliers?
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#14
One of the other advantages of LTO are their high discharge AND charge rates, most cells are rated for 10C discharge AND charge, some even 15C, this makes them much more suitable to solar charging than lead acid that require trickle charge above 80%.

Yes I purchased from OSN, I did get pricing from Kylin in early October:
LTO 66160 30AH----US$9.9/PC
LTO 66160 35AH----US$13.5/PC
LTO 66160 40AH----US$18/PC

The latest pricing from OSN was cheaper than Kylin.

I purchased 215 cells in my first order which at the time was US$20 for 30AH cells:
Product Amount US $ 4472.00 AU$6211
Shipping Fee US $ 2485.00 AU$3451

GST was 10% of the product amount, so AU$621.10
Customs clearance and processing, etc added about AU$500

All up about AU$11,400 which is AU$53 per cell delivered.

You might struggle to get a decent price only ordering a handful of cells, if you search aliexpress for "lto 66160" you can delivered pricing of about $62 AUD for 30AH and $65AUD for 40AH. These prices seem about right for small quantities with delivery.

Eg: Pack of 10 cells
https://www.aliexpress.com/item/10pcs-2-...31554.html

I know there are other forum members who have purchased from OSN, and maybe someone from Yinlong, I am not aware of anyone that has ordered from others like GTK or Kylin.
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#15
I'm planning an LTO purchase in a few days, 330 cells for an 11s-30p pack at 24v, 1200Ah
I see you got an inverter/charger, could you share what charge settings you're using?

There was discussion on the forum about setting Absorb timing to zero and just using the bulk voltage setting to charge.

I am a little concerned about the effects of a slower rate of charge on the cell chemistry, but it definitely looks better than the AGM batteries I've worn out!
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#16
I haven't had a chance to dial in my inverter yet as we've only just finished the pack assembly, I was hoping to have them installed this weekend but I ran out of weekend.

But from playing around with individual cells and 12v 5 cell packs on a variable power supply I have found the following to work well:

Charge voltage 2.8v per cell
Float voltage 2.7-2.75v per cell

These settings also happen to almost perfectly match AGM charge settings when configured as 5s per 12v battery.

Others have tested, reported and graphed that the bulk of an LTO cells energy is stored between 2.4 and 2.6 volts, depending on how configurable your charger is, with your pack configured as 11s it will only just reach 2.45v per cell at full charge.
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#17
Thanks Baron, I'm getting more confident in the choice of LTO.  These look like they might be a 25+ year pack if I treat them right!
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#18
Based on most of the worst case scenario brochures and sales specs, 25+ years should be a safe bet.

I understand it's still early days for LTO tech so it's difficult to predict how long they will last, I have seen rated life expectancy from 10,000 to 30,000 cycles, some even stating better than 80% usable capacity after 30,000 cycles and a 100 year shelf life.

It will be interesting to see.
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#19
This I am following as in about 10 - 15 Years I will be going ahead with on Off-Grid Home and this will be interesting to watch for longevity
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#20
So what am I missing on these LTO batteries?  They seem like the perfect battery.

I'm tired of replacing the lead acid batteries on my boat every couple of years and have been looking at lithium. Stumbled on to these LTO here..  (Have 5 samples  (40AH) on the way from Kylin btw..  USD20 / pc FOB for sample , 16.5 for volume.   Bit pricey on air freight will need to look at ocean if I go volume.. From another vendor I got a quote of about USD2 / pc to Sydney port.. for the ocean freight piece.  Clearance / gst / customs / final delivery extra but its a good guide .. but if you marry those two up its suggests port landed cells for about USD18 / pc.  Not bad. Believe these are YinLong mfg.)

Based on what I've read so far these will last forever.  There even seems to be a very real chance that a 5S pack will charge quite nicely,  and properly,  with my existing Lead Acid Charger if it is set to cool gel or AGM.  Dont believe I can do that with other lithiums.

So again, what am I missing ?  Isn't this too good to be true?
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