Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Batteries, Chargers, and Battery Management Systems.
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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by HK12K » Jan 22 2020 1:33pm

240Vdc? Sounds zesty. I'll take that potting option, thank you very much.

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by 999zip999 » Jan 22 2020 2:52pm

Zesty 240vdc 400amps to my folding bikes 🔋 for a 15 min charge.how long do you think it takes you to run into circle k and get a coffee and donut ?
Can you say floating plasma ball. Small mushroom cloud and a flying folder.

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by nickceouk » Jan 22 2020 3:37pm

999zip999 wrote:
Jan 22 2020 2:52pm
Zesty 240vdc 400amps to my folding bikes 🔋 for a 15 min charge.how long do you think it takes you to run into circle k and get a coffee and donut ?
Can you say floating plasma ball. Small mushroom cloud and a flying folder.
I am laughing with you on this one :lol: :lol: :lol:

2160 wh NMC battery + 1 Huawei R4850G 3kw AC/DC DC rectifier -
this is the 45 minute newish target after scrapping the 10 min. LTO.

My current setup is feeling rough for awhile now - no suspension and a sturdy but heavy aluminium frame. Got a pinch flat rear wheel - the front is doing ok and I love the piece of mind of having foam insert in the front wheel. The foam insert is battle tested now...no issues ridding on a flat front tire several days after the event either.
I would like to use fat tired 20" on the foldable bike like in the pics I posted on this thread. Foam inserts on fat tired is less of a thing.
Dash cam rear view to ditch the mirror and compressed air horn built into the otherwise hollow segments of the frame tube. I also want to have all the frame redone in half stripe highly reflective coating + daytime high vis .
List goes further GPS trackers....

This all has to happen in the real world - money side to be specific runs in the several K. Job work or lottery 8) :lol:
Last edited by nickceouk on Jan 22 2020 4:34pm, edited 3 times in total.

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by 999zip999 » Jan 22 2020 4:09pm

I have a 24s A123 20ah pouch cells charge as 2 * 12s packs with mean wells 24v turned to 28.8v and a 12.6v HP 550 power supply times two. This is the limit for my garage outlet. Any more juice it will trip breaker. I think 42.3v @ 14mps each in 50 min. For 6.5 years 1,480 cycles 24,000 miles still going strong. No BMS just bulk charge and check. I used to always balance charge with thigh-high. 1420 that popped and then thunder something 1220 both popped and now I have two una9plis+ which I never use I just play with them once in awhile just booked charge and check. Quality matters. Looking for new battery now 72v so need help too.
. This bike is just too heavy.
Last edited by 999zip999 on Jan 22 2020 5:18pm, edited 1 time in total.

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by nickceouk » Jan 22 2020 4:25pm

999zip999 wrote:
Jan 22 2020 4:09pm
I have a 24s A123 20ah pouch cells charge as 2 12s with mean well 24v turned to 28.8v and a 12.6v HP 550 power supply times two. This is the limit for my garage outlet. Any more juice it will trip breaker. I think 42.3v @ 14mps each in 50 min. For 6.5 years 1,480 cycles 24,00 miles still going strong. No BMS just bulk charge and check. Looking for new battery now 72v so need help too.
. This bike is just too heavy.
I am eyeing NMC 14s6p 7.5ah cells which will be about 13.5kg (each cell is 159 grams but it's a Chinese taobao seller so might be lighter/heavier due to misunderstanding on my side)
72v22ah 20s3p is just over 9.5kg mean cells weight.
Here are the cells (white packaged shell)
https://m.intl.taobao.com/detail/detail ... 4209833213
Taobaofocus is the way to order for me.

These cells were tested 100 cycles with 2c charge current in a YouTube video with next to no degradation.

You are not short of other options for sure :lol:

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by amberwolf » Jan 22 2020 5:02pm

just some stuff to run by you, as food for thought:

if those are like most of the nmc cells i've seen / used, they'll only have a 0.5c charging rate, meaning it will take about 30 minutes to charge to mostly full, with the appropriate charger. probably about 45-50 minutes for "really full", assuming all cells are well-matched and balanced (potentially much longer if they get unbalanced easily). the cells you link to may well handle faster charging rates, as technology is always improving...but i don't knwo those cells, and tend to distrust the quality control and cell-matching ability of any of these.

the 10c discharge rate is just a peak, for a few seconds, and 5c or less is the continuous rating. meaning, a 22ah pack would handle momentary peaks of up to 220a, with 110a continous possible. i doubt you'll need more than 1c (22a), so even if they're crappy cells they'll probably handle that. ;)

however...since you're in the uk, then if you have the space for a "block" battery about the size and shape of a classic .50 caliber ammocan, and don't need a custom shape, you can use the cells that jimbob01 is selling over here
viewtopic.php?f=31&t=102908
that are also nmc, and which are easy to bolt together and make packs from, not requiring any special machines (spotwelder, etc) to assemble. just need either busbars or lugged wires to connect them. tehy're what i use on my bike and trike, and are good quality cells that stay balanced, and i've been using mine for years now. (and all of mine came to me used already). they're not miracle cells or anything...but they're almost certainly significantly better than whatever random chinese stuff you may find. ;)

a 14s1p pack is 20ah and capable of 100a continous and 200a peak discharge, and easily 10a charge rates, so about 30 minutes to charge. they can handle twice that charge rate, so they can actually charge in about 15 minutes if you used a 10a charger (though the faster you charge them, the shorter their lifespan, similar to discharging them harder). they're more likely to stay balanced, based on my experience, than the generic stuff is, so unlikely to take extra time to balance and finish charging. (i actually don't use a bms on mine, and just let the controller lvc and/or the cycle analyst lvc protect them from overdischarge, and mine stay within a couple of hundredths of a volt of each other in either 1p or 2p configurations).

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by nickceouk » Jan 22 2020 5:32pm

amberwolf wrote:
Jan 22 2020 5:02pm
just some stuff to run by you, as food for thought:

if those are like most of the nmc cells i've seen / used, they'll only have a 0.5c charging rate, meaning it will take about 30 minutes to charge to mostly full, with the appropriate charger. probably about 45-50 minutes for "really full", assuming all cells are well-matched and balanced (potentially much longer if they get unbalanced easily). the cells you link to may well handle faster charging rates, as technology is always improving...but i don't knwo those cells, and tend to distrust the quality control and cell-matching ability of any of these.

the 10c discharge rate is just a peak, for a few seconds, and 5c or less is the continuous rating. meaning, a 22ah pack would handle momentary peaks of up to 220a, with 110a continous possible. i doubt you'll need more than 1c (22a), so even if they're crappy cells they'll probably handle that. ;)

however...since you're in the uk, then if you have the space for a "block" battery about the size and shape of a classic .50 caliber ammocan, and don't need a custom shape, you can use the cells that jimbob01 is selling over here
viewtopic.php?f=31&t=102908
that are also nmc, and which are easy to bolt together and make packs from, not requiring any special machines (spotwelder, etc) to assemble. just need either busbars or lugged wires to connect them. tehy're what i use on my bike and trike, and are good quality cells that stay balanced, and i've been using mine for years now. (and all of mine came to me used already). they're not miracle cells or anything...but they're almost certainly significantly better than whatever random chinese stuff you may find. ;)

a 14s1p pack is 20ah and capable of 100a continous and 200a peak discharge, and easily 10a charge rates, so about 30 minutes to charge. they can handle twice that charge rate, so they can actually charge in about 15 minutes if you used a 10a charger (though the faster you charge them, the shorter their lifespan, similar to discharging them harder). they're more likely to stay balanced, based on my experience, than the generic stuff is, so unlikely to take extra time to balance and finish charging. (i actually don't use a bms on mine, and just let the controller lvc and/or the cycle analyst lvc protect them from overdischarge, and mine stay within a couple of hundredths of a volt of each other in either 1p or 2p configurations).
I messaged jimbob01 who sells them.
Happy to avoid shipping charges, dangerous goods fees , handling &import taxes and the long waiting time.

Had to recheck on the 30 min charge - 20ah cells charged at 10a(0.5c as per spec) would actually take 2 hours right?
I would need to charge at 40a to get 30min full charge from empty.
They are specified as 1000 cycles when charged at 0.5c to 80% capacity. Charging at 40a likely going to be expensive (wasteful).

If the price is right(£9 a cell as advertised) then it's still worthy so thumbs up :thumb:

It's easy enough to fit everything in a helmet box on a rear rack. Would be good to have it slide in/out to charge at home when not touring ... perhaps with a handle retrofitted.

Thanks for sharing :wink:

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by John in CR » Jan 22 2020 6:04pm

john61ct wrote:
Jan 22 2020 11:41am
John in CR wrote:What motor to use really depends on how small a diameter tire you can live with.
Gravel roads, scrub, desert and forestry tracks, badly surfaced roads, to me means 20" will be too small, so 24-26" outside diameter? Thinking fatties, at least 2.5" tires?

> You also have to look at the top cruising speed and range you want.

The cargo and hill climbing capabilities is 99.9% of my drivetrain design focus right now. If energy efficiency were optimized for cruising at under 15mph, that'd be fine and top speed is truly irrelevant; a 20-25 max would be fine.

A modular swappable battery pack system will give me the necessary range. Hauling supplies, propane, drums of water so an extra pack or two's NBD. On flat terrain hoping for 400-500lbs, will reduce as needed for hilly country....

______
....Outstanding:

Would it be better to have the front & back hub motors match each other? ....
Sorry this is so off topic of the original post, but I can't help but answer a question asked.

No hubmotor or pair of hubmotors excel at low rpm high load. Silence is a must for me, so those high rpm mid-drives that sound like an electric chain saw are out for me. The big hubbies can make the torque required to forgo a big gear reduction, but since you don't need high speed your power requirements aren't high. Using the power calculator here (http://www.kreuzotter.de/english/espeed.htm hauling a 700lb load up a 20% grade (f'ing A steep) at 20mph (fast for a big load on a steep off road grade) only requires 6kw at the wheel, so I'd use a high speed wind QS 205 v3 and run it out of the wheel geared down to a top speed of 30mph. Depending on the tire diameter and motor Kv you're probably looking at about a 3:1 reduction with a 20s pack. With a nice big drive sprocket a chain drive can be very quiet as long as you use a sprung chain tensioner. You want the high speed wind motor, because they're capable of more power at any given voltage, and 20s or 21s is about the best in terms of value, performance and efficiency with any DD hubbie while staying conservatively below the common voltage limits of economical high performance controllers.

If you have terrain that requires 2wd, then by all means put a slow wind motor in the front wheel...a MUXus 3k would be plenty and save some weight compared to a 205. There's no need for the extra weight of a bigger motor up front, as you'll want to run it at much lower power than the rear. To prevent it from ever binding up the suspension I would have the front always pulling, so I'd gear the rear such that with both in the air the front wheel would spin very slightly faster than the rear at any given throttle position. That way the front motor is always providing positive thrust to the bike, despite the rear mid-moto providing most of the thrust. The much lower torque and power demand up front means a Nuc 12F is plenty for the front. Nuc's make running one throttle simple, but with 2wd think I'd separate the regen braking function, but that's something to experiment with. Heavy DD hubbies present special challenges to attach to suspension forks, so I'd try just the one mid mounted hubbie first.

You mention "swappable packs"...who would be carrying the extra packs? Connecting a packs aboard in parallel is the way to go, so extra space to connect range extender packs in parallel makes sense, but don't carry packs not in use whether charged or discharged.

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by amberwolf » Jan 22 2020 6:08pm

nickceouk wrote:
Jan 22 2020 5:32pm

Had to recheck on the 30 min charge - 20ah cells charged at 10a(0.5c as per spec) would actually take 2 hours right?
yeah, sorry, i'm still exhausted from nightmares (from peanutbutters' death three weeks ago), so math is not my friend right now (actually, it never is, but especially now).
I would need to charge at 40a to get 30min full charge from empty.
i don't know how they would handle that. their spec is only 1c max, meaning 1 hour charge time. you'd have to test if this is feasible (monitoring cell temperatures, etc).

i usually charge mine at about 1/4c, 12a for a 14s2p pack (40ah) with the meanwell hlg-600h-54a mounted under the trike. just plug in an ac extension cord from the trike to the wall and walk away; come back in a few hours and it's done. if i really think i'll need faster charging on some long trip (rare) i can carry a pair of those wired in parallel for 0.5c charging. if *really* needed 1c charging, i have four of them that can be wired in parallel for that (including the one already on the trike), but have never had to do that.

realistically, if i only needed one recharge on a trip like that, i'd just carry a second 40ah pack, as it wouldn't weigh much more (35-40lbs) than the four chargers (about 30lbs), and i wouldn't have to stop at all. just wire the two in parallel, and off i go. ;) 40lbs isn't even a tenth of the gross weight of the trike and me, so not that noticeable, though it certainly would be on a folding bike. (even the less-than-20lbs ofa 14s1p pack in the wrong place on a small folder would be a huge handling change).

if i were going to put one of these packs on a typical 20" folder (don't know what yours is like) i'd put it right over the front wheel on a frame extension from the top/downtube, like some of the small-front-wheel cargo bikes do. it wouldn't be on the fork or bars, whcih can make for undesirable handling changes in steering.

then you also still have your whole rear rack/panniers/etc for other stuff, hopefully not as heavy. ;)

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by nickceouk » Jan 22 2020 6:31pm

amberwolf wrote:
Jan 22 2020 6:08pm
nickceouk wrote:
Jan 22 2020 5:32pm

Had to recheck on the 30 min charge - 20ah cells charged at 10a(0.5c as per spec) would actually take 2 hours right?
yeah, sorry, i'm still exhausted from nightmares (from peanutbutters' death three weeks ago), so math is not my friend right now (actually, it never is, but especially now).
I would need to charge at 40a to get 30min full charge from empty.
i don't know how they would handle that. their spec is only 1c max, meaning 1 hour charge time. you'd have to test if this is feasible (monitoring cell temperatures, etc).

i usually charge mine at about 1/4c, 12a for a 14s2p pack (40ah) with the meanwell hlg-600h-54a mounted under the trike. just plug in an ac extension cord from the trike to the wall and walk away; come back in a few hours and it's done. if i really think i'll need faster charging on some long trip (rare) i can carry a pair of those wired in parallel for 0.5c charging. if *really* needed 1c charging, i have four of them that can be wired in parallel for that (including the one already on the trike), but have never had to do that.

realistically, if i only needed one recharge on a trip like that, i'd just carry a second 40ah pack, as it wouldn't weigh much more (35-40lbs) than the four chargers (about 30lbs), and i wouldn't have to stop at all. just wire the two in parallel, and off i go. ;) 40lbs isn't even a tenth of the gross weight of the trike and me, so not that noticeable, though it certainly would be on a folding bike. (even the less-than-20lbs ofa 14s1p pack in the wrong place on a small folder would be a huge handling change).

if i were going to put one of these packs on a typical 20" folder (don't know what yours is like) i'd put it right over the front wheel on a frame extension from the top/downtube, like some of the small-front-wheel cargo bikes do. it wouldn't be on the fork or bars, whcih can make for undesirable handling changes in steering.

then you also still have your whole rear rack/panniers/etc for other stuff, hopefully not as heavy. ;)
Image
With rear rack
or even this one on a suitable folding bike(with rear rack + panniers for gear
Image

Edit : Daga stroke - tilting cargo trike This one might just be it for me in terms of capacity and weight distribution (battery at its lowest point should improve stability and handling)
Image
Image

The only thing I would be tempted is to also have a way to fold/disassemble and bag everything to comply with public transport logistics.Granted the weight will likely be significant
enough...will have to revisit/re examine when I get close
Image
Image

Thanks this has gone in a very exciting direction for me.

Hope you don't get caught on peanut butter again
:wink:
A small gesture to you via the link in your signature from me :D
Last edited by nickceouk on Jan 23 2020 3:28am, edited 3 times in total.

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by amberwolf » Jan 22 2020 7:03pm

nickceouk wrote:
Jan 22 2020 6:31pm

Image
With rear rack
or even this one on a suitable folding bike(with rear rack + panniers for gear
Image
those kinds of things would work, too, and give you even more cargo space. but i was thinking of stuff like these that have racks as "part of the frame":
https://electrek.co/2018/08/27/electrek ... -part-suv/
Image

https://www.perennialcycle.com/shopcast ... e-project/
Image

and others; there's several here on the forum too including a couple of complete custom builds but i can't find them right now.
Hope you don't get caught on peanut butter again
:wink:
i wish taht was the case, but losing dogs has never been easy for me, and his death has been much harder than most for whatever reason. its not as bad now as it was at first, but it's not very good yet either.
A small gesture to you via the link in your signature from me :D
thanks--i appreciate it. :) most of these go to help feed the monsters (i still have three st bernards, yogi, kirin, and jelly, and they eat about 15 cups or so a day, depending on the particular dog food, so even the biggest bag only lasts a couple of weeks or so). sometimes i can use a bit here and there for ebike projects and the like.

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by 999zip999 » Jan 25 2020 10:16am

AW is right you live in the UK I would buy those eig cells in a heartbeat. They look easy to bolt together

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by nickceouk » Jan 25 2020 10:31am

999zip999 wrote:
Jan 25 2020 10:16am
AW is right you live in the UK I would buy those eig cells in a heartbeat. They look easy to bolt together
I got 13 cells off James to test today. Come well packaged and from a new stack of 50.

Female terminals are M3 size from what I found and I also ordered copper rivets to then thread myself with some copper strip 7mm width as a busbar etc.

I have to wait about a week until I put everything together for performance test and recommendations.

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by 999zip999 » Jan 25 2020 1:02pm

It's best that they're all the same voltage. And balance before you put a new BMS on it. Or just put sense wires on to monitor.

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by nickceouk » Feb 03 2020 9:40am

Punx0r wrote:
Jan 21 2020 10:06am
nickceouk wrote:
Jan 21 2020 9:51am
Ride a folding bike long distance? Nope!
...
and Street AC/DC recharging in 40mins
...
As to 25kg+ battery it's not a deal breaker on its own ...
25kg (by the time it's built into a sturdy pack you're looking at ~30kg) on a bike frame is a lot. Before commiting to something like that I really would strap a bag of sand or bricks to your frame or on the rear rack, take a ride and see how the bike handles at speed to ensure you're not going to find the thing flexing all over the place/wheelie-ing/death-wobbling.

40mins charge time = much more doable with readily available, relatively energy-dense li-ion cells
Did a test with 13s 20ah cells today. I am guessing the added weight is under 25kgs but the results are challenging enough to put any more weight on hold.
Wheelie's - yes definitely an issue. I gathered because I placed the added weight in a top box on the rear rack - the front hub is struggling. If I move the weight in the triangle area if the frame it would help with wheeling but the weight will sit a lot more on the front fork and the hub is already near the limit to what the dropouts can take(vibrations, and generally feeling like it's stressing too much).
The wobble - yes : the added battery is too high in too far away from where the motion is generated and handling is compromised to a point of no joy.

Too many issues to go on. The way forward is through something like the Daga stroke trike frame design. Batteries can be placed low and that's a good place to explore handling (thought the battery could be better off made to swing so that everything remains lighter to lean the bike one way or another - agility with the wrong design compromises the fun when the overall bike is heavy.

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Re: Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver

Post by nickceouk » Feb 03 2020 9:40am

Punx0r wrote:
Jan 21 2020 10:06am
nickceouk wrote:
Jan 21 2020 9:51am
Ride a folding bike long distance? Nope!
...
and Street AC/DC recharging in 40mins
...
As to 25kg+ battery it's not a deal breaker on its own ...
25kg (by the time it's built into a sturdy pack you're looking at ~30kg) on a bike frame is a lot. Before commiting to something like that I really would strap a bag of sand or bricks to your frame or on the rear rack, take a ride and see how the bike handles at speed to ensure you're not going to find the thing flexing all over the place/wheelie-ing/death-wobbling.

40mins charge time = much more doable with readily available, relatively energy-dense li-ion cells
Did a test with 13s 20ah cells today. I am guessing the added weight is under 25kgs but the results are challenging enough to put any more weight adding on hold.
Wheelie's - yes definitely an issue. I gathered because I placed the added weight in a top box on the rear rack - the front hub is struggling. If I move the weight in the triangle area of the frame it would help with wheeling but the weight will sit a lot more on the front fork and the hub is already near the limit to what the dropouts can take(vibrations, and generally feeling like it's stressing too much).
The wobble - yes : the added battery is too high and too far away from where the motion is generated so handling is compromised to a point of no joy when riding the thing :o

Too many issues to go on. The way forward is through something like the Daga stroke trike frame design. Batteries can be placed low and that's a good place to explore handling (thought the battery could be better off made to swing so that everything remains lighter to lean the bike one way or another - agility with the wrong design compromises the fun when the overall bike is heavy.

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