Lithium Titanate (LTO) battery pack for electric motorcycle

Hello good day to all of you.

I have just created this profile here in endless sphere but I have been following the forum from some time ago an wanted to share with you my first project.

Actually I bought a small electric motorcycle about 3 years ago:


This bike came with a 72v 30Ah system compromised of 6 lead-silicate batteries.
it wasn't bad but even the promised 80kms of range the ONLY time I discharged them they only gave me 70 kms and the rest I usually only used between 20 to 40 km and also always topping them up as much as possible to 'keep the batteries healthy'
even so about a year and a half after purchasing the bike I started noticing the degradation in the batteries and after that there where several times I was left stranded with low voltage.

now I have a little more than 3 years and the bike usually spends the 90% of the time sitting in the garage. and I have been doing almost everything in my urban bike (non electric). I was with the Idea of building my own pack using 18650 but my knowledge is limited and here in my country is complicated to find good quality cells so I started looking everywhere fot batteries ideas, after lots of reading and messing around Aliexpress I pulled the trigger in a LTO pack because from the experience of lead batts I wanted longevity and reliability.
the pack is a 72v (84max) 30ah pack, and an adjustable charger of 10 and 15 amps.

I am now a fan of LTO.

Quite the opposite, I live in a big city with lots of places to charge ( ironically any filling station will work), I really needed long life spam, some resistance to abuse, and fast charging.
As I said before, the original panel is a +60 kg lead battery array that when new it gave me about 70kms range killing the batteries to minimal voltage, the LTO pack being the heaviest of lithium chemistries is 25kg for the same 30Ah even slightly more and is spected to give about 120km in granny mode and 90km kicking hard in green lights, and being able to charge at 15amps I can get around 70% of charge in some +-20mins.
I have more than 3 years considering different lithium chemistries, obviously I considered LiIon but I don't think 1000 cycles would work for me, LiFePO4 was the one I was just to get but then I found LTO, and knowing about the lower energy density oh titanate I thought that was perfect for me.
I have to go to several places not just a commute fixed place so I wanted a bike that where useful as a gas bike.

For the application, I don't see anything wrong with LTO.

Fast charging without a short lifespan, combined with lots of charging places and a good fast charging system built in is pretty ideal for city use.

https://www.ebay.com/itm/lithium-titanate-battery-11ah-cells-22-pcs/283434157851?hash=item41fdfe071b:g:gcYAAOSw1jpb~6jj


these look to be a great deal.

How is your acceleration compared to your lead batteries? Any noticeable difference?

any update on this? I am also as a thought experiment looking into this battery tech; i know the specific energy density is worse than lithium ion but the advantages seem interesting. Think big 1.5kWh+ battery being 80-85% charge in 30 minutes.

e-beach said:

How is your acceleration compared to your lead batteries? Any noticeable difference?

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Absolutely! the lead pack was 68kgs and the LTO is 23KG less than 25kgs with the charger.
the start of the line as the top speed where substantially enhanced, even at low voltage I can keep +55km.
handling and even moving of the bike is much easier.

although the charge speed is not as I calculated: the charger is adjustable for 2 charging speeds; 10A and 15A.
I was hoping to have the standard 10A for home charging getting from minimal voltage to full charge in about 1h and 40 to 50 mins but takes about 2h30mins, and the 15A fast charging I use it to charge between stops to go from 40% to about 80% to 90% in about 15mins but it takes 25 to 30mins (not that I complain about it).
the range is a little bit lower that I thought. I haven't get the bike to a dead stop but I calculate a 80+ mks range but I haven't gone below 61v and the pack have 56v cutoff.

bakaneko said:

any update on this? I am also as a thought experiment looking into this battery tech; i know the specific energy density is worse than lithium ion but the advantages seem interesting. Think big 1.5kWh+ battery being 80-85% charge in 30 minutes.

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Yeah I totally recommend!, as I said my system is a 84v 30Ah so more than 2 KWh and I get about 40% to 80% in 30mins with 15A charge speed. I could have got 30% to around 90% in 15 or 20 mins with 20A that is the manufacturer states is the max charge speed but I'm ok with my 15A.

What project do you have in mind?

flat tire said:

I am now a fan of LTO.

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Yeah, I was worried with the range but now I'm fine with it. the max range I have gone in a day is +150kms with a charge of 45mins.

after this I'm considering my next project a Ninja 300 replica with 96v system with Altairnano 66Ah cells.

Geass'Sogeki said:

Yeah I totally recommend!, as I said my system is a 84v 30Ah so more than 2 KWh and I get about 40% to 80% in 30mins with 15A charge speed. I could have got 30% to around 90% in 15 or 20 mins with 20A that is the manufacturer states is the max charge speed but I'm ok with my 15A.

What project do you have in mind?

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Exactly as you have except for a bicycle but with 48-52V 1-2kW motor and about 1.5kwH LTO battery. I want to get like a 1-1.5 kW charger if possible and get like that 20min 0-80% charge. ATM, I have a 72V 3kW (~2kW with my battery) gas generator serial ebike hybrid. I won't break that down but keep it. But, I love to try pure electric with that powerful onboard charger and charge at gas stations and etc. Just something that Li-ion cannot do presently. Also, the cycles and high discharge seems real nice. Of course you take on extra weight; I think for me it would be 50lbs for 1.5kwH but my current bike is like 100lbs.

bakaneko said:

Geass'Sogeki said:

Yeah I totally recommend!, as I said my system is a 84v 30Ah so more than 2 KWh and I get about 40% to 80% in 30mins with 15A charge speed. I could have got 30% to around 90% in 15 or 20 mins with 20A that is the manufacturer states is the max charge speed but I'm ok with my 15A.

What project do you have in mind?

Click to expand...

Exactly as you have except for a bicycle but with 48-52V 1-2kW motor and about 1.5kwH LTO battery. I want to get like a 1-1.5 kW charger if possible and get like that 20min 0-80% charge. ATM, I have a 72V 3kW (~2kW with my battery) gas generator serial ebike hybrid. I won't break that down but keep it. But, I love to try pure electric with that powerful onboard charger and charge at gas stations and etc. Just something that Li-ion cannot do presently. Also, the cycles and high discharge seems real nice. Of course you take on extra weight; I think for me it would be 50lbs for 1.5kwH but my current bike is like 100lbs.

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Sounds great! Totally recommend a 52v sys if you can stuff that amount, and a 2kw motor that would make that a beast!. (show it when you have it done)
I have a 1.26Kw for a 84v max charger, so if you want a +1.5kw charger that would be a 52v 30Ah. I recommend to get a dual speed charger because you may trip some breakers in some old installations.

Can you post a link where you bought your 72v (84max) 30ah pack and charger?

Thanks!

Hello Good day to all of you.
I'm sorry I have not updated in a very long time.

the link where I bought the pack is here:
https://www.aliexpress.com/item/32964566677.html?spm=a2g0s.9042311.0.0.66374c4dBZgxUk

Up until now I have put about 17.000kms on the bike and to December of 2020 it worked fine.
that was late January that I started to notice that the BMS kicked in about 60% of the usual range, At first I though it was an unbalance cell then when I opened the pack I found a couple of swelled Cells (it is pouch cells).
The bike got about 2 months parked in the freaking shop while the new cells arrived from china and also decided to upgrade the BMS to an ANT BMS (that critter is a nice one) since I don't know if blame the cells for bad manufacturing or the bms for being a cheapo one and not being customizable (didn't even have balancing function).
with the new BMS now i can see some stats like amps, wattage, cells levels, etc, and noticed that the so called charger in reality doesn't charge to 10a and 15a but to 5a and 10a... (f@acking lying Chinese). so I'm looking for a waterproof 1.4kw charger to install directly on the tail of the bike.

Wow 17000km!

Just shows the infrastructure for proper monitoring maintenance & protection

can make a huge difference!

Personally once that's in place, regular testing protocols implemented to track SoH% decline and rising ESIR over time

I'd start with a new pack

maybe keep two going so downtime is minimized.

Packs are consumables after all!

https://batteryhookup.com/products/case-of-12-lishen-2-5v-18ah-lto-30-000-cycle-new seems a good deal

Indeed yes if the description is honest.

Toshiba SCIB is the top quality.

Nice thing about LTO is going dead flat doesn't render the whole pack scrap

so fewer secondhand deals are likely to be duds.