Practical advice on achieving the 10min full charge LTO(Titanate) cells are meant to deliver
- Thread starter nickceouk
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nickceouk
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Not all foldable bikes are flimsy and feeble :Punx0r said:
[img]https://i.redd.it/dgktsm2ohom31.jpg[/img]
A variation on this fat foldable ebike type setup is a good candidate for touring plus maybe some public transport possibility. Powered by 6-8 tiger sharks
and Street AC/DC recharging in 40mins ...it's a maybe for sure 8) The sharks could be individually replaced or kept in a bag/trolley during public transport/transit.
The public transport is based on the Eurostar trains requirement for now - 85cm folded and needs to be covered/bagged.
As to 25kg+ battery it's not a deal breaker on its own ...
The primary reason why LTO won't be happening for me is that NMC/NCA cells + DC-DC or AC- DC(Huawei 3kw rectifier or meanwell hlg led ps to name 2) has the range and volume and only then weight benefits.
nickceouk said:
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
I said nothing about battery type, my points are true no matter what LI battery, LTO is the only chemistry where longevity is unaffected by high charging C-rate.Punx0r said:
And certainly pricing is not anywhere discussed here, nor should it be.
Glad to hear you're getting realistic, dropping the 10-min charging in this case.
If the light weight and folding portability is important, start out with say a pair of packs mounted so they're easy to swap out.
Then after you've logged a few thousand miles, got all the other issues sorted, you'll be in a position to make more informed judgment calls about adding (even) more weight.
If the light weight and folding portability is important, start out with say a pair of packs mounted so they're easy to swap out.
Then after you've logged a few thousand miles, got all the other issues sorted, you'll be in a position to make more informed judgment calls about adding (even) more weight.
nickceouk
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john61ct said:
Thank you for guiding me along the way.
I started with a sketchy sketchy idea and now with all the input into account I gained better clarity on what's worth pursuing as well as how to make it happen.
Some adjustments will be needed while charging and I do love the freedom to explore good food locally
nickceouk
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Punx0r said:
Thanks, NMC cells - with 40min charging(or as close as I can get to that) is definitely where I am at.
Switching chemistries to NMC cells(32650 at 7.5ah) means that 45ah will be about 12kgs(lowering my voltage to 48v while testing too 13s6p)
12kg is a half the original challenge and what a relief that is too :lol:
999zip999
100 TW
Number one reason why batteries are all about compromise how to balance the ACT .
Hillhater
100 TW
Remember, reducing the voltage by 1/3 , also reduces the Whr capacity (and range) by 1/3 !
Unless you increase the Ah’s,...which will increase the weight again !
999zip999
100 TW
How to balance your needs and have it fit and deliver the watts needed and keep balance over time with lots of cycles. Like A123 pouch cells. But smaller and lighter. Or to fit the ACT. The performance. The deed. Or compromise.
John in CR
100 TW
nickceouk said:
I pretty much stopped using my other ebikes since installing the dual 12F Nucular controllers on my 98kg workhorse scooter. The perfect throttle control and variable regen on it makes the others unpleasant to ride in comparison. It's running at 20kw peak input and with my usual aggressive in town riding I average about 60wh/km, though I see about 35wh/km average on flat highway cruising at 70/80kph. The battery pack is two 12s Chevy Volt modules though I don't use 3 cells and run it at 21s. I typically use a 4A cheap Chinese charger that I tuned to cut off at 4.07V/cell, and with my 6A charger that cuts off at 4.17V/cell I can charge at 10A with an adaptor dual XLA connector I made up, or charge to full for long rides. Usually I charge only 2-3 times a week with the 4A charger, but usually not even to it's cutoff since typical days rarely exceed 50km day and those longer days always include some steady state cruising where wh/km is much lower. My longest trip is 100km down to the beach, which is a 1200m very gradual descent with wind generally at my back and I ride to conserve and draft when it's convenient and always arrive with juice to spare. On the way back fully charge the night before and ride slower as well as focus a lot on drafting, but I still stop for a leisurely lunch running dual chargers to pick up at least 15ah of charge at the restaurant and market. I can't wait to see the energy usage for the beach run now that I'm running the more efficient (the motor and controllers are more efficient) Nucular controllers.
Sounds like a great setup!
Feedback from anyone in the below most welcome
Are these features / phrases
"direct access to the halls and phases"
"phase current control"
"hall delay/advance"
"current sensor on each phase connection, directly measure amps for each phase"
all synonymous with true FOC?
From the Nucular thread:
> Nucular controllers use shunts on the battery side and some math to calculate phase amps.
Does this imply **not** not controlling as per some of those above phrases?
I'm currently figuring that multiple motors 2WD is the way to satisfy my heavy-cargo / mountain roads need for highest possible torque especially at lower rpm before considering gearing.
Is the biggest Nucular the best (or at least an excellent) approach?
What type hub motors would suit best? Looking at QS maybe 273, or 205 if lighter is better
Would it be better to have the front & back hubs match each other, or does this controller take care of the torque sync'ing well enough they don't need to?
Feedback from anyone in the below most welcome
Is that because the Nucular is true FOC?John in CR said:
Are these features / phrases
"direct access to the halls and phases"
"phase current control"
"hall delay/advance"
"current sensor on each phase connection, directly measure amps for each phase"
all synonymous with true FOC?
From the Nucular thread:
> Nucular controllers use shunts on the battery side and some math to calculate phase amps.
Does this imply **not** not controlling as per some of those above phrases?
I'm currently figuring that multiple motors 2WD is the way to satisfy my heavy-cargo / mountain roads need for highest possible torque especially at lower rpm before considering gearing.
Is the biggest Nucular the best (or at least an excellent) approach?
What type hub motors would suit best? Looking at QS maybe 273, or 205 if lighter is better
Would it be better to have the front & back hubs match each other, or does this controller take care of the torque sync'ing well enough they don't need to?
John in CR
100 TW
john61ct said:
My dual controllers are on a 6phase motor. I actually built it first with dual 6phase HubMonsters, which would need 4 controllers, but the front suspension just couldn't handle the 15kg motor and I didn't like the way it handled. I would have loved to keep the billy goat mountain climbing since it's mountainous here, but I've had no thermal problems at all with the Nucs on it now.
What motor to use really depends on how small a diameter tire you can live with. You also have to look at the top cruising speed and range you want. Some of those motors have really high no-load current at significant rpm, and since those losses occur whether under power or not they can have a significant impact on range at cruise. That's where my high efficiency hubbies slaughter all others...too bad they discontinued production years ago...too costly and the factory never truly understood how to take best advantage of their capabilities.
I don't know how Nuc's measure phase amps and leave electronics details to the experts. I used the auto-tune during setup, and it spun the motor up several times during the timing portion of that. You can go in an change timing manually too as well as the point where is switches away from the halls for timing. During the timing part of the auto setup it also measures and adjusts for hall placement inaccuracies, which I think is a big part of the efficiency gain on common hubbies that have the 3 halls placed so close together.
999zip999
100 TW
I agree on highest quality cells for life and balance. Automotive salvage is as close as we get. John how many ah is your battery ?
Thanks for responding John!
> 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?
or does this controller take care of the torque sync'ing well enough they don't need to?
______
Is the Nucular true FOC?
Are these features / phrases
"direct access to the halls and phases"
"phase current control"
"hall delay/advance"
"current sensor on each phase connection, directly measure amps for each phase"
all synonymous with true FOC?
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?John in CR said:
> 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?
or does this controller take care of the torque sync'ing well enough they don't need to?
______
Is the Nucular true FOC?
Are these features / phrases
"direct access to the halls and phases"
"phase current control"
"hall delay/advance"
"current sensor on each phase connection, directly measure amps for each phase"
all synonymous with true FOC?