Begode Rs Resolute, the first EUC using LFP battery chemistry?

[Ben Kim]

1 hour ago, RagingGrandpa said:

Yes but... the reduction is capacity dominates the story.

• Li-Ion 18650GA delivers about 75% of its "label capacity" for an EUC, before tiltback voltage (end of useful capacity).
• LFP 18650 delivers about 85% of its "label capacity" in a similar theoretical EUC. But the label capacity is less than half of the Li-Ion 18650.

So to get a 10% bump in 'discharge efficiency,' you gave up half of the original rating. It's a net loss.
(And no surprise, as LFP has been on the market for decades now.)

The old story was: The main thing that LFP can do that Li-Ion cannot is: 20A per 18650-size cell. (And be immune to thermal runaway.)
It means an MTen3-sized pack could power a Sherman-sized motor. For about 5 minutes
But with new designs, the industry managed to get Li-Ion 18650's up past 20A, leaving LFP behind in terms of discharge performance.

 

What I don’t understand is supply chain issues aside, why they won’t go back to 18650 wheels. They got it mostly right back in 2018-2019, but now it appears to be a case of manufacturers trying to fix something that was never broken to begin with. 

[supercurio]

Both Electric Dreams on a YouTube post and @Afeez Kay in this last video describe the packs as "Lithium Polymer"

 

It seems unlikely this is what we've seen with drilling in the pack, the current trends of battery trends for EVs in China and the lower energy density, hence my best guess of LFP instead.

I wonder if Begode is telling partners that their pack is based on "Lithium Polymer" or if it's something lost in translation.

[RagingGrandpa]

27 minutes ago, supercurio said:

I wonder if Begode is telling partners that their pack is based on "Lithium Polymer" or if it's something lost in translation.

It may be pouch cells, instead of cylinder cells.

We can make pouch cells with a gel ("polymer") electrolyte, in many chemistries, including NCM and LFP. The cell voltage usually reveals the type: 3.2Vnom for Ferrous types, 3.6Vnom for Cobalt types.

So calling it LiPo may be technically correct, but isn't really helpful. It's almost certainly LFP.

[supercurio]

17 minutes ago, RagingGrandpa said:

It may be pouch cells, instead of cylinder cells.

We can make pouch cells with a gel ("polymer") electrolyte, in many chemistries, including NCM and LFP. The cell voltage usually reveals the type: 3.2Vnom for Ferrous types, 3.6Vnom for Cobalt types.

So calling it LiPo may be technically correct, but isn't really helpful. It's almost certainly LFP.

Ah thanks, makes sense.

Let's see if we get some more details in an upcoming teardown or from a distributor asking more questions.

It could at least mean that these packs are not using cylindrical LFP cells like these, which might bring challenges in terms of dimensions anyway.

 

Regarding speed and voltage, I was wondering practically at what what voltage this wheel, if LFP is confirmed would actually operate vs Li-ion.

Nominal voltage is 3.2 V, so 32s would mean 102.4 V nominal voltage for most of the operation (aside from voltage sag)

Not a huge increase in free-spin compared to an existing 100.8V HT wheel, but that's if it was always at 4.2V which cannot be the case.

Not bad, although less than what we can expect from the S20 which is something like a range between 126V to 99V, counting 4.2 to 3.3V

Edited December 7, 2021 by supercurio

[RayRay]

Maybe add a dash of manganese to increase the voltage? (LiFeMnPO chemistry may be making a comeback.)

Edited January 16, 2022 by RayRay
more better

[Unventor]

5 hours ago, meepmeepmayer said:

Ugh. 

The RS is a fantastic wheel you can't really buy because of the battery problems.

But 1800Wh to 1020Wh sucks.

Why not just use better Li-Ion cells? *cough* V12 *cough* Is it the Begode firmware or BMS or whatever that can't handle such cells? Do all such cells blow up when the power draw is too high, so they don't really work for such a wheel?

I think it is more complex than that. I don't know for sure, but this is why I think this (here goes)

How some riders seem to use their GW/sisterbrands are going to the very edge to the limit both speed and how they push (aggressive) their wheel and often use higher amps to charge the wheels/batteries too. It seems to me from the talk that they have not put as much effort into making sure thing do not get out of hand. I am not talking one model but how we have seen models since i joined the EUC community.

The development of GW/sisterbrands seems to me to just add a bit more of everything in the same path they used before. But checks and control point to keep it safe was not in focus at all. So adding a different battery type well it is a start but it takes a bit more to innovate. 

If they took a moment to explain what they done and why then I would be less skeptical, but that has never been the strong point of GW either. 

If the V12 only relied on "better" quality of cells then I would expect we would see battery issues here too. For the record some V11 have had battery packs failing, but that seems to be a faulty bms, but it never lead to a fire from what i know of so far. So Inmotion have had some issues but it do not lead to wheel fires. Yes we have heard of a very few fires on V10f but they got narrowed down to water intrusion of the battery, and a rework or self fix got setup by Inmotion. 

So the way I see this is all about design philosophy and how that is portraited into the product. I am not secret about I prefer the Inmotion way better. But i also welcome thoughts to using a mostly safer battery chemistry, but it will most likely come with drawbacks. At least from now. 

[Planemo]

2 hours ago, Ben Kim said:

What I don’t understand is supply chain issues aside, why they won’t go back to 18650 wheels. They got it mostly right back in 2018-2019, but now it appears to be a case of manufacturers trying to fix something that was never broken to begin with. 

I think you answered it in your own question - 'supply chain issues'. The 18650GA's (and genuine, proper Grade A ones, not some shitty back door ones) have been a nightmare to get hold of for ages, and those you can/could get went sky high on price. The EUC companies simply felt they didn't have any option but to source alternatives.

Shame because as you say the original 1230Wh MSX was and still could be a great lightweight, fast wheel. Sanyo/Panasonic 18650GA's were largely bulletproof and strong as an ox. I'm just super happy that my Sherman has them  may be the last of the great wheels that did!

[RagingGrandpa]

7 hours ago, supercurio said:

"Current limit: 240A"

Sounds like a peak current for motor phases... I've seen 210 in logfiles but never 240... it makes me wonder if this is "more," or "the same as before."

Does anyone know: Has "current limit" been a specification listed for any previous EUC?

[Flying W]

A long time ago, about 10yrs ago now, I had an LFP pack on my dual sport to save weight. It would spin the hell out of my starter but only for a short time. If I had any difficulty starting (clocked pilot jet, wrong jets for altitude etc) the battery would die before ya knew it. 

I loved that battery though, it was only 1lb 2oz vs the stock lead acid that was over 11lbs. 

I would still want more than 1020wh in my wheel though and info wish my RS had a 6p 18650 setup vs the 4p we have now. Voltage drop is huge! 

I get great range cruising in the low 20mph range but my work commute just drinks the battery. My RS is the high torque and riding in the mid 30mph range to work just eats the battery. Round trip is almost 12 miles and I get home in the mid 70% range. If I did the same ride going slow I'd be around 90%.

This hobby always feels like chasing a unicorn that eats 4 leaf clovers, I want the torque, with minimal voltage drop and Sherman cruising speeds....for less money 

[supercurio]

12 minutes ago, RagingGrandpa said:

"Current limit: 240A"

Sounds like a peak current for motor phases... I've seen 210 in logfiles but never 240... it makes me wonder if this is "more," or "the same as before."

Does anyone know: Has "current limit" been a specification listed for any previous EUC?

I also heard about 230A limits on their current board from a trusted source, but not specifying what kind of current is talked about, so: unclear.

Playing with that some time ago, I also noticed that Sherman also gets over-powered around this phase current.

And although the packs can't provide this in a sustained way, maybe it could be battery current when including the capacitor as buffer?
Not sure.

Another noticeable change is the use of 10% battery for beeps instead of a specific voltage, indicating that this will indeed not use voltage as a proxy for state of charge (would match with the LFP theory)

Edited December 7, 2021 by supercurio

[Eucner]

It is nice to have a risk level option. Now you can choose between burning and non-burning Begode wheel. So only blame yourself if your wheel catches fire .

[EMA]

waiting to know exactly what kind of battery they use, could be a nice off road/fast charging wheel 

[Paradox]

Alien rides posted this.

https://alienrides.com/collections/electric-unicycles/products/begode-rs-resolute-electric-unicycle

 

Notice the description of the battery.

 "The battery is at the heart of the electric unicycle and provides power to the motors. For most batteries there is risk of fire if damage, puncture or thermal runaway occurs. For the new Resolute batteries, dangerous fires are avoided. The RS Resolute will NOT use lithium ion technology, instead a new proprietary technology will be used, the details of which will be released in the future."

[yoos]

15 minutes ago, Paradox said:

The RS Resolute will NOT use lithium ion technology, instead a new proprietary technology will be used, the details of which will be released in the future.

If they imply Begode has a proprietary battery technology this sounds ridiculous  The battery industry and science is so big that Begode has neither the resources nor expertise to develop anything remotely original.

[supercurio]

Quote

The RS Resolute will NOT use lithium ion technology, instead a new proprietary technology will be used, the details of which will be released in the future."

 

Here you can tell that @Alien Rides people are hanging out too much with silicon valley disruptive technology founders and whatnot.

Silly keywords to hype it up.
But also Begode, very transparently didn't share any information, including to the distributors leaving everyone speculate.

Edited December 8, 2021 by supercurio

[Jim_x01]

According to the Begode video with a hole in the battery - it is DEFINITELY LiFePo4 cells. These guys on YouTube telling this is LiPo just don't know what they're talking about - they just don't have any technical knowledge about these battery types but they needed to name them somehow to talk about them, so they've chosen to name them "LiPo".

I've assembled the same LiFePo4 type of battery for my motorboat as a second "house" battery, 105Ah. So when I did it I studied the market a lot for any types of safe-for-a-boat and high-enough-capacity cells, and came to these LiFePo4. You don't want a fire on a boat in the middle of the ocean, even more than with EUC.:) And if you search videos of how they burn - it is EXACTLY the same as on this Begode video - they just give up a lot of smoke, but without any significant fire. There are a lot of different types of these cells on AliExpress in all different shapes and capacities. No wonder Begode has chosen these too.

And this was my first thought when I saw all the nasty fire-incidents with EUCs - I thought to try to use LiFePo4, and calculate how much capacity of these would fit into EUC. And suddenly I see this thread which exactly reflects this same thing I was thinking about!..:)

I'm sure this is a good move from Begode - at least those who lives in an apartment and is concerned about fire hazard now could relax and buy this model. Some sacrifice in capacity, but a good win in power draw from the cells, charging speed, and most important - fire safety. Just storing the EUC in some non-flammable box in the apartment would be absolutely enough with this type of batteries. In contrast to how I currently prepare to store my first EUC outside my house (RS-HT, still on the way from China):

There will be two EUCs there (my wife wants one too), so I even think to lay down some ceramic tiles inside of that box, to be sure that 1mm aluminium walls of this box would not melt in lithium fire and some close-by wood would not start burning too... So with the LiFePo4 cells - I would not even bother about that, it's much more safe with them...

[Tawpie]

7 hours ago, Jim_x01 said:

how I currently prepare to store my first EUC

I really like the looks of your box! You obviously have excellent fabrication skills, nicely done.

One thing about LiFePo that should be mentioned... assuming they are the same chemistry A123 tried to introduce about 15 years ago, a really interesting characteristic of the A123 product was exceptionally high discharge rates and (for the time) insanely high charge rates. Seems I recall 50C discharge and 30C charge. A123 didn't make it in the US and was sold to a Chinese company—if these are the cells Begode is using and (big and) they can design the power delivery system properly, really high thrust could be had without damaging the battery.

And if you can design a safe charging circuit (and plug into a capable mains supply!), it is possible to be wicked fast at recharge. The small capacity isn't such a buzz kill if you fully recharge in minutes.

But that's a ton of ifs, ands and there are buts in there as well. Nevertheless, LiFePo is an interesting chemistry. I worked on a project where we fooled around with A123 batteries for a hand held hot air tool—they were really nice cells but I couldn't help but worry about trying to charge them at 30C... it seemed to be asking for trouble. I always thought they failed because there wasn't a solid use case for them, but an EUC might actually provide that opportunity. If you do the design properly.

Edited December 12, 2021 by Tawpie

[Jim_x01]

48 minutes ago, Tawpie said:

I really like the looks of your box! You obviously have excellent fabrication skills, nicely done.

I'd be happy to accept this, but to be honest I've actually just bought this metal case in a store.  This is one installed by workers in back of their tracks and used for tools - it's sealed by rubber around the door with proper water-channels. It's perfect in dimensions for two EUCs. Maybe would be useful for others too, there are smaller sizes of these boxes to fit just one EUC...

But still yes, I have some fabrication skills and a workshop with a big milling machine and other tools in my house... So I plan to install some pressure-relief into this box, 'cause if it would get lithium fire inside when being air-tightly closed - it would become a big heavily-explosive bomb. I need to fabricate some sealed flanges with aluminium foil that would pop from small pressure and open a hole in this box for the air going out... And of course I'm going to disassemble the new RS as soon as I receive it and do a full waterproofing, with fully enclosing batteries and all electronics by submerging in flexible potting compound (already ordered it here: https://www.amazon.com/dp/B07R18FJN6?psc=1&ref=ppx_yo2_dt_b_product_details). We have really heavy rains here in NZ..:)

[yoos]

While it is great to have a non-flaming battery, as an apartment-dweller I am still concerned about lethality of the smoke. You would need a fume cupboard to make it properly safe. On a related note: does LiFePo also prevent a thermal runaway scenario in the case of a short? I would like to understand whether the shift to LiFePo just replaces "spontaneous combustion with explosions and toxic smoke" by "spontaneous toxic smoke" or is there also a drastic reduction of the chances of anything "spontaneous" happening? ("spontaneous" in the sense of a delayed catastrophe caused by earlier riding/charging/crashing events but actuated later, when the EUC is resting) 

[Jim_x01]

1 hour ago, yoos said:

I would like to understand whether the shift to LiFePo just replaces "spontaneous combustion with explosions and toxic smoke" by "spontaneous toxic smoke" or is there also a drastic reduction of the chances of anything "spontaneous" happening?

The "toxic smoke" will still happen, you'll just get no powerful fire that burns even under water (like usual lithium cells do). Just a lot of smoke, plus some heat inside the LiFePo4 cells... but not even close to these powerful "thermite bombs" that EUCs turn into after thermal runaway of currently used lithium cells... So, all your neighbors will still be dead from a toxic smoke, but your apartment and the whole building will be perfectly not burned out. It's already 50% better than with usual lithium battery...

Even NiMh battery will give you a thermal runaway if you short it. Just not so violent as current lithium cells. And the LiFePo4 battery will be not too much worse fire-wise than the NiMh shorted in this video...

 

Edited December 12, 2021 by Jim_x01

[Chriull]

1 hour ago, Jim_x01 said:

So, all your neighbors will still be dead from a toxic smoke

Would be interesting how toxic such smoke really is. I'd guess neighbours will survive it without problems

2 hours ago, yoos said:

as an apartment-dweller I am still concerned about lethality of the smoke.

Imho every smoke is (can be) lethal. Firstly just in because of the absence of oxygen. Additionally carbon monoxide from incomplete combustions hinders absorption of oxygen.

Plus soot and particulate matters hindering lung function.

By the amount of plastics/compounds in every household already many acid gases are created by fire. Like hydrocloric acid gas from burning pvc.

According to this paper/article/report on smoke from li ion battery fires- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5577247/#!po=0.724638 - the main additional emission is HF (hydrofluoric acid gas), POF3 just in some seldom cases?

So it could be that li ion smoke has the toxidity like "normal" smoke plus the acidity of "plastics" smoke??

Edited December 12, 2021 by Chriull

[Jim_x01]

Of course I was joking about dead neighbors.

But there is still a good chance to become dead from this smoke plus carbon monoxide if somebody is sleeping and can't react quickly to the smoke... but you could say the same about any house-fire... In most cases you'll still wake up from the fumes or smoke alarm and run away.

The most that I like in these LiFePo4 - is no significant fire hazard. And this would relax me a lot, not requiring to prepare a sealed metal case standing outdoors away from the house, wood and plants, on a gravel ground, with ceramic tiles inside and a pressure-relief... I definitely don't want to have any risk to burn out my expensive house. In case of LiFePo4 I would just install some simple metal case maybe even inside the house with just additional smoke-alarm above it, not closing its door tightly instead of pressure relief.

But I'm still not sure how much range I would need in my use case of EUC. So maybe I would still prefer the current lithium cells because of higher capacity, especially that the safe storage would be already prepared. If I lived in apartment though - I would definitely choose the LiFePo4 (paying with some lost range). Same as I went for my boat - I have enough power stored in 105Ah LiFePo4 house-battery (plus starter lead-acid battery), and absolutely don't care about any fire hazard when fishing far away from land. If I see any smoke - I would have enough time to just throw the battery outboard on some leash without burning myself.

Maybe 1020Wh would be still enough for some use cases? Some not-far commuting maybe?.. And the ability of much higher power draw and much faster charge could compensate the lower capacity a little bit...

Edited December 12, 2021 by Jim_x01

[AtlasP]

While obviously safer batteries are a major value and marketing asset, I'm having trouble determining the intended audience for this particular configuration of size (particularly weight) and range.

• Surely the majority of the core Begode crowd aren't going to buy a 1kwh wheel at this point.
• Those outside the core Begode crowd and concerned about safety already have a range of options by other brands with minimal fire risk, all of which have far greater range-per-weight.

So you're looking for someone who is concerned enough with safety yet who is willing/interested to buy a Begode for some reason who will consider buying a 60+lb wheel that only has 1kwh range. ¯\_ (ツ)_/¯

Perhaps some of you will argue that Begode fans will tell their brand-new-rider-friends-who-are-also-worried-about-the-fire-horror-stories to buy this instead of an InMotion or King Song as an entry-level wheel, but that same Begode crowd is usually the loudest contingent arguing that riders should skip entry-level wheels and buy something high end with massive range and that anything less than 1800Wh is a toy. So again, ¯\_ (ツ)_/¯

 

Edited December 13, 2021 by AtlasP

[Kekafuch]

1 hour ago, AtlasP said:

While obviously safer batteries are a major value and marketing asset, I'm having trouble determining the intended audience for this particular configuration of size (particularly weight) and range.

• Surely the majority of the core Begode crowd aren't going to buy a 1kwh wheel at this point.
• Those outside the core Begode crowd and concerned about safety already have a range of options by other brands with minimal fire risk, all of which have far greater range-per-weight.

So you're looking for someone who is concerned enough with safety yet who is willing/interested to buy a Begode for some reason who will consider buying a 60+lb wheel that only has 1kwh range. ¯\_ (ツ)_/¯

Perhaps some of you will argue that Begode fans will tell their brand-new-rider-friends-who-are-also-worried-about-the-fire-horror-stories to buy this instead of an InMotion or King Song as an entry-level wheel, but that same Begode crowd is usually the loudest contingent arguing that riders should skip entry-level wheels and buy something high end with massive range and that anything less than 1800Wh is a toy. Again, ¯\_ (ツ)_/¯

 

 

hows the discharge graphs? If the power is sustained throughout the entire battery pack, would it then be interesting? 
 

Then here’s another rumour …

 

[Tawpie]

8 hours ago, Jim_x01 said:

Maybe 1020Wh would be still enough for some use cases?

It's desperately small... might give a Begode aficionado an hour's fun? I know the teenie battery on my S18 is a total buzzkill, and I go slow. Tough call on BG's part... but they sort of had to do something. LeaperKim isn't going away. InMotion has stepped outside their comfort zone with a solid offering. KingSong is aggressively moving up the power ladder. Competition—it can be a really great thing!