French firm Gouach is pitching an Infinite Battery with replaceable cells
arstechnica.com
arstechnica.com
We've been testing our batteries for 3+ years on an existing free-floating mobility fleet with our friends from Pony in France, they've been sustaining heat, cold, rain, snow, shocks, people throwing them in rivers, etc, and we've been able to improve them incrementally!
Today we're very proud of our product: it matches the performances of the best brands, it offers connectivity, and we plan to open-source the protocol and make it hackable, so you anyone can use it on any bike!
For now we've reverse-engineered and reimplemented major protocols (Bosch, Bafang, Brose, etc)
Happy to take any question you might have, and if you're interested, you can order a battery here :) https://gouach.com/products/infinite-battery-complete-kit?va...
(BTW: we've been trying to reach out to Louis Rossman to talk about what we do on his Right to Repair podcast, but couldn't reach him, perhaps he's here, or someone could ping him to know if he'd be interested? we love what he does and he was a source of inspiration for us!)
Oh: and of course, since this is HN, I have to mention that we coded our firmware in Rust!
> Implementing Geolocalisation [sic] on Batteries
It should be fairly easy to integrate them into Apple's and Google's FindMy networks, as they are BLE-enabled. Maybe that's your plan? This is the kind of improvement an open source firmware would enable (though if you document the internals well enough, we could also bring our own microcontrollers or custom firmware).
Anyway, I am itching to buy one, but I do not own an e-bike yet (just a few old "La Poste" batteries I would like to salvage the cells of). I will be in the market of an e-bike next year, and would love it if your battery was an option offered by bike shops with new bike purchases.
For example at least here in the US lithium ion tool batteries come with lots of different connector shapes just to lock users into a brand and are not repairable. Manufacturers charge a lot for the batteries, often more than the tools, and if (when) they go bad they just have to be thrown out. Manufacturers even occasionally "upgrade" their battery designs so that they're not backwards compatible to force purchase of new batteries for newer tools. A universal repairable tool battery would likely be a big hit!
Another use case might be USB power packs. These are all sealed and not repairable. They go bad after awhile and the whole thing is waste when it's most likely just a single cell failing.
Thanks for coming here.
I have a question - how does the device aid in identifying in which cells have gone bad, and then do the necessary rebalancing to match the load level of the cells in the string?
Also, cell replacement is a concern in EVs that placing in a cell of different make and age to the existing ones will mean that cell will have a different charge curve to the others, making very easy for the pack to go 'out of sync' again. How do you address this issue?
You also mentioned that you spent a huge amount of time on making sure the contacts stay in place during the shaking that comes with riding a bike - which is super important as jumpy contacts could cause DC arcing which is a fire hazard.
How would you ease the concern that such a thing absolutely cannot happen?
For second-life cells, you indeed have to match the cells, we don't necessarily expect people to do that themselves, but we will partner with battery recyclers to get second-life cells, test and match them, and sell back those packs at a lower price as an additional revenue stream for the recycling industry!
Our battery would be perfect for this kind of use-case
For the shaking of contacts, rest assured that: our batteries get tested by third-party authorities like any other batteries, and go through intense stress-test (check https://www.instagram.com/p/C-c_NEbtE4N/ for an example)
And as a second proof, our batteries have been in use in a free-floating mobility startup, Pony, for around 3+ years, they have been subjected to all kind of heat, cold, rain, snow, people kicking bikes, people throwing bikes in the river, etc, and they are working great!
One of the biggest compatibility challenges, Vallette said, was finding a way to work with Bosch's mid-drive motors. The communications between a Bosch motor and battery are encrypted; after "a serious effort," Gouach's app and battery should work with them, Vallette said.
Bosch old batteries don’t work with their own new controller anymore. Not saying it will never happen but Bosch can’t do that every week either.
They're geographically and organisation-wise so far from each other, they're basically two different companies.
Is that so? Every time I have brought my bike into a Bosch dealer, they ask if I want firmware updates. One of them was a significant change (changing the "sport" mode to a mix of "tour" and "turbo" depending on torque and speed).
There are in fact, a few devices out there that did precisely this and successfully hosed reverse engineers (ask me how i know).
Don’t ever depend on reverse engineered protocols for anything you care about. This game of cat and mouse only has one end -- the manufacturer is at a significant advantage.
I tip my hat to this team for successfully reverse engineering, a encrypted protocol. But if they really think they can sell something based on that, I rescind that hat tip because that is fucking insane. There are just so many ways that the manufacturer could fuck with them. And the reverse logistics of shipping back a large battery for all those pissed-off customers who just want a refund are going to cost a lot of dollars.
I personally would not put a cent into this company unless they agreed to only ship products for devices that already support completely normal interoperability. This business of reverse engineering and attempting to sell based on that is going to be a money drain that kills them (thus ending all customer support). I am willing to bet that they have not even priced out ($$$) the cost of a return to them, nor estimated what percent of customers will need it when the encryption changes or something else doesn’t work.
- Depth of Discharge - how often you go from full to low battery? Going twice from 80->30 (which accounts to a single cycle) is much better than single 100->0 cycle
- Thermal management - what are cell temperatures when battery is being charged? Maybe it is charged in direct sunlight? This will kill battery pretty fast. At what temperatures are the cells when driving the ebike?
- Ebike/scooter probably being charged to 100% more often than necessary.
- Did you leave your battery at winter completely discharged or fully charged in your garage? Bad.
TLDR: Info I gathered about reading how to take care of Lithium NMC batteries which are so widespread.
On the user side folks may not be keeping them optimally charged.
What I can't guess is how this translates into expectations for the components of an e-bike. There must still be a limit to how much size and weight a rider is willing to tolerate.
On the other hand, maybe a high quality battery would last a long time and not need service, but the market isn't ready to believe it.
That's where the e-bike is crossing barriers a bit. People will ride them much further, and getting the e-drivetrain repaired can be a real time and money sink. So you want it to be reliable, more reliable than the rest of your bike even.
According to different sources, the average kilometers travelled by motorists are under 25k km/year (including Europe & US).
You'd be surprised by how many amateur cyclists ride more than that each year.
You wouldn't.
As an 8k km/yr cyclist with a lot of cycling friends, I can tell you that 12.5k/yr is extremely high for an amateur. Sure, there are some, but a truly tiny proportion.
8k/year eats bikes, BTW. I used to wear out rims regularly before I switched to disks and chains/sprockets didn't even last a year (on a fixed gear bike).
> Even avid cyclists could never hit the kilometres travelled by your average car user in a year.
And you tell it yourself:
> Sure, there are some
So, if OP really thinks that no cyclist can ride more than what an average motorists drive a year, then even "but a truly tiny proportion" would appear as a surprise to them.
Also, just looking at my Strava right now, amongst the 30 friends that I follow (I'm picky on my follows), more than a third are on their way to ride more than 25k this year. The most advanced is going to reach 23k by the end of the day based on his current numbers and habbits.
How, where and when you ride your bike will be a huge factor in how much wear it gets. For instance, my commuter' chain usually get less than half the mileage that my road bike' chain get because city is dirty, I ride no matter the weather, don't clean the chain after each ride and keep putting strong torque since I constantly have to stop and start. Same goes for brake pads: when I commute I hardly do 200m without having to brake, whereas I can go for 20km without having to touch my brakes on my road bike.
I said an avid cyclist, which is quite undefined so fair enough. What I meant was an enthusiast still, not a sport rider or someone you could consider an amateur athlete (many road riders).
Road riding gets you a lot of KMs and hours in the saddle too, like you said in quite a specific wear pattern. I ride for hours on my MTB and my commuter but would never come close to the hours and KMs of road riding, and I will be replacing my MTB sprocket and brake pads much sooner than my commuter.
I think we're more or less on the same page though, and since all cities and cultures are a bit different we could be talking past eachother without specifics at which point my general comments go out the window anyway.
That's partly why when people talk to me about "how many km do you ride each year?" I respond in hours on the saddle.
In France for example the average yearly distance travelled by car is closer to 12000km not 25000. More achievable but still a lot.
25000km/year is ultracycling territory for amateur cyclist. Yes some people do it, a lot definitely not and I don't think many of them have a full time job.
Sorry!
And if I had written 25000, I would have been afraid of people telling me that it should be 25,000 or 25 000
Basically as long as it pass safety regulations, manufacturers will aim to make the lightest (and cheapest) parts. That's why they use plastic in low-end bikes and carbon/titanium in high-end ones.
You could put motorbike brakes on a bike, and a set of pads would last you a lifetime. But with so much weight there, the bike would feel unbalanced and hard to handle. So you'll need to put weight elsewhere to find balance. And soon enough, you'll have a bike weighting 50kg. Nobody would want to come near this monstrosity. People legitimately want a bike that they can power with their legs and handle easily when they are not riding.
Keep in mind that a single car tire is heavier than a whole road bike. It necessarily results in less atoms, and faster wearing.
That's why I talked about "parts", not "frames".
Cheap pedals and cheap brake levers? Plastic.
> The lighter materials cost more, not less
Plastic is lighter and cheaper than steel and aluminium.
Carbon is lighter than steel and aluminium but much more expensive.
Basically all high-end pedals include some kind of titanium or carbon
I don't care a hoot about my car, I wash it once a year whether it needs it or not.
It's the same for a commuting bike. My road bike on the other hand gets washed, tyres pumped, transmission cleaned and lubricated on every ride.
I think most club riders would be just the same.
It's not just vanity, dirty transmission is more tiring to pedal when you're trying to keep up with a group and when you're coming down hill at 50mph you want to know your brakes will work.
And look at the average railway station bike parking.
Bikes have it rough. They have crappy suspension, usually are used on roadways that are much worse than the ones that cars ride on, they have to regularly deal with impact and g-forces that you rarely see in cars outside of actual accidents and people drop them all the time. I've been working on bikes all my life and if there is a form of bike damage that I have not seen yet it would amaze me.
Yeah there definitely seems to be a polarised dichotomy here.
Bikes are either very pampered or have a squeaky chain and gears that don't index properly with nothing in between!
I admire that, I used to wash my truck once a year too, until I ran out of time.
This is true for bikes, and after decades of marketing and fearmongering, basically the inverse is true for cars.
I'm saying this as a european non car-owner who's never been to the US, but my impression of car brain from over here is that anything that approaches light-weight is seen as a "death trap" by a majority of US drivers, especially because the rest of car users drive cars that literally have the size of WWI tanks.
Glorified shopping cart.
Might as well buy a hatchback.
Having the motor means people don't care about things like slow rolling tyres, heavy finishing kit or the weight of the transmission to handle the extra torque.
That in turn means you need heavier brakes to stop.
Luckily not every bike has to be the same and we can pick and choose as needed. I'd rather have a lighter bike and have to service it once a year (if that) but that's just me.
In fact, when I add up the time and money spent taking care of the periodic maintenance of my car, which involves driving it to the mechanic's, it's way more than what I would consider to be remotely acceptable for maintaining my bike.
I think it's the BMS, Batteries in cars usually get used between 20/80% and have active cooling and heating while ebikes don't.
Cells aside, cars have very good suspensions, and their batteries have been designed with very pricey component to eliminate shocks and vibrations.
On e-bikes, most batteries will have to sustain those, and we've seen a LOT of commercial batteries who were out of order for a simple $5 electronics component which was broken, and which couldn't be replaced because the battery was not made to be repaired (soldiering, glue, etc)
I don't do e-bikes but I've had E-vespas and e-scooters and replacing a cell isn't really something I've had in mind. I've had lots of failures, none of them were from the battery. They all died too, before the battery.
The next step of the lifecycle is recycling, and that's done by professionals who do have arc welders, so they don't require such convenience
Our repairable battery is actually quite convenient even for recyclers: many studies have shown that if you can get pristine cells, without all the casing / electronics / plastic parts as you're recycling the cells, you get back a much more pure recycled lithium at the end of the process!
why an app? Why not a simple light or error code on device?
Just speculating, but I guess there are a lot of reasons why a bluetooth app makes sense
If one product has an app, and the next one doesn’t, people will choose the one that does.
I don't want to increase the cost and complexity, and reduce the runtime of the thing with an onboard tiny LCD and an array of buttons to navigate menus. The interface could be available over a Bluetooth app, or or a self-hosted webpage, or make it show up as USB mass storage or a USB virtual serial port, or an actual RS232 or RS485 or TTL serial port, or I can grab it off a storage device with an EEPROM clip, or hook up my Tag-connect cable and a bus pirate and get I2C or SPI or whatever unnecessarily custom UART protocol you want to invent, or I can buy your dedicated HMI device with the LCD and buttons connected by a custom cable (don't want to buy yet another, I already have too many kicking around from decades of work with random industrial VFDs and PLCs and stuff), or I can hook up my MSO to some test pads and read the signals directly... But not everyone has all those tools and cables.
Like it or not, the standard has become a Bluetooth app. I wish the standard was a self-hosted webpage, so I could connect my laptop to a buried RJ45 connector, set a static IP to point my NIC at the right subnet (or the device could embed a router to assign my laptop a compatible IP over DHCP, but most don't), or I could turn on an integrated wifi adapter in the device, ignore and revert the protestations of my device and OS that the connection was unsuccessful because it can't ping connectivitycheck.android.com or captive.apple.com or msftconnecttest.com or whatever through the battery pack SSID. But by the time your user manual tells the user to go to their network adapter properties and set their IP address to 10.10.0.2 (on their iPad, LOL) you've lost most people long ago.
Like it or not, the standard has become Bluetooth and an app, and not without compelling if frustrating reasons.
Maybe a small screen on the device would work, since it has replaceable cells you do need to know more details about which cells are weak.
- it gives much more detailed and fine-grained informations
- it allows user (optionally) to register for automated safety alerts
- but more importantly, it allows users to override themselves the communication protocol of the battery, to adapt it to any bike
For now we've hardcoded Bosch, Bafang, Brose and a few others (more coming), and we plan to open-source the communication protocol soon so that anyone can upload their own WASM code on the battery to talk to any controller!
What if all the software and hardware systems of the bike were open source, not just the battery.
Many consumers just don't want to worry about battery health. Reportedly, battery degradation anxiety is driving down used EV prices in the US.
There are not multiple battery providers. You can only get batteries through gogoro and they dictate the price (it govt fixed for X amount of year and then who knows what happensl. Till recently you couldn't charge the scooter/batteries at home (even now it's made impractical)
You in effect are renting your vehicle
It's only successful in Taiwan due to slick marketing and intense nationalism
Additionally, we've seen more and more customers wary of the environmental and social cost (children mines, etc) linked to lithium batteries, and who are looking for more durable solutions
But the so called 'USB' 18650 torch I got has a custom magnetic charger, yuk!
The last 3 hand-held vacuum cleaners are 4x18650, but have all been welded, and non replaceable.
Bike battery is already flagging, but newer replacement design has different connector.
Having a universal bike battery like this sounds perfect!
Even better if they make it into a generic power bank design; 48V would be perfect for connecting to solar panel for charge, then use it on the bike, lawnmower, laptop, maybe a small 230V inverter add-on.
Or a smaller 8/12 bank for pushing back against power tool company 'lets change the battery standard' every 2 years so that we can sell the same tools again.
Nice to see some attempt to fight this locked-down throw-away manufacturing obsession. Well done!
The form factor might be (mostly) standardized, but the cells themselves are not. There's a huge amount of variation between them, and using a cell improperly can quickly lead to some very nasty fires.
This means user-replaceable bare cells go right out the window, and you're left having to build a custom protection circuit for the cells you want to use - which means you essentially end up with custom batteries.
The solution might be a standardized way for the cell to communicate its health and capabilities to the device using it - but good luck getting the industry to adopt it. It provides no immediate benefit to the consumer while making the product more expensive, so they'll only do that when the government forces them to.
Great idea, I would love to see them offer solar chargers as well.
I was thinking of designing an open source UPS at some point, I guess I could architect it around this battery (though LiFePo would make more sense). I will have a look at the docs when they are out, I hope there's a communication/diagnosis bus, though Bluetooth would work as well.
if you want the same kind of style diy-er box-for-batteries I suggest the Trampa offerings. Similar focus on safety and novice level DIYer capability but much larger capacities and arrangements.
Our product also comes with a high-end connected Battery Management System (the "brain" of the battery), and with a sturdy and fire-resistant aluminum casing!
There's the Ligo 10X (https://ebikes.ca/product-info/grin-products/ligo10x-battery...) which makes 99Wh battery packs that can be connected together, but otherwise it just seems like rules lawyering.
There really needs to be standardization of battery packs for ebikes instead of proprietary ones, so that one could rent a battery at their destination.
Privileged enough to fly somewhere specifically to ride bicycles? C'mon, I think you can find a good enough bike to rent when you get there.
I've also done it the other way, my main bike has S&S coupling so I could bring it aboard the Eurostar. For touring I prefer my own bike, because I have the racks set up for my panniers, but when I do that, I prefer travelling by ferry/train.
You totally have the option to fly with a regular muscular powered bike.
I would rather have the whole battery be replacable. And when you want to replace, you trade-in your old one for a discount on the new one.
E-bikes tend to be quite heavy, and many of them have designs that are very much not optimized for weight.
> I would rather have the whole battery be replacable.
They are. And the replacements are single-source and are very expensive.
As a single item they are pretty well priced for the power they offer.
The RadKick 7 (which RadPower calls a "lightweight bike" weighs 55 lbs.
Racing bikes like the $10K Trek Domaine Carbon weighs less than 30 lbs, but has a much slimmer (and lower capacity) battery pack than what Gouach seems to be targeting.
The Domane I was talking about is the SLR carbon series, it ranges from 28.3 lbs for the SLR6 ($9K) to 26.1 lbs for the SLR 9 ($17K)
The Domane+ ALR is the Aluminum framed series and is heavier, but their specs page says it's 31.73 lbs for the ALR 5 (ML frame size).
https://www.trekbikes.com/ca/en_CA/bikes/electric-bikes/elec...
https://www.trekbikes.com/ca/en_CA/bikes/road-bikes/performa...
The battery itself is 3.3kg, so quite comparable to other models, keep in mind it comes with a sturdy aluminum casing.
What we mean by "replacing" is that you can change the cells of the battery yourself (or by asking at your local bike shop), so you don't need to trade-in the whole battery! This makes you gain time and a lot of money!
Would this be possible in 12V ?
Can we also put LiFePO4 instead of Li-ion ?
Subscribe to our newsletter if you want to be informed :) https://gouach.com
480 watts == 10 amps @ 48V == 15 amps @ 32V
An electrically commutated motor (brushless DC) in an e-bike will almost certainly have a speed controllee, if you want more range you simply have to go slower ;)
I’m much more familiar with three-phase AC induction motors from my day job and the speed on those are (most commonly) controlled by adjusting the frequency with a variable frequency drive while maintaining the same voltage instead of directly controlling the voltage like on a DC motor.
I see a niche application but personally hope they get it to market and make it compatible with Shimano. My double sized battery is a frankenbattery: pcb from original with custom printed case fitting onto the original attachment device using the batteries from two original batteries. Measured and balanced of course. Safety is "meh" I guess because DIY. I'd like to replace it with something more properly designed.
Edit: here’s the publication if you’re curious: https://www.sciencedirect.com/science/article/pii/S240589632...
Edit-edit: wow I got two citations!!! Never thought anyone would read my paper, that’s amazing.
If the packs are not perfectly balanced, the batteries just short into each other and explode, and BMS can’t do anything because there isn’t any per-cell switch (cost).
It’s not just a matter of balancing voltage either, the cell profiles (voltage vs SOC) have to be the same otherwise you end up with 1 cell doing all the work. Simply put, when you mix and match cells of different brands, models, or even ages, they don’t integrate evenly. This results in a few or even just 1 cell doing a majority of the work during both charge and discharge, maybe 10x higher than its safety rating, guaranteed fire…
Also end-user is expected to do the math and input the battery’s total current rating into the motor controller? Yeah, nah, a hundred kids will think it’s cool to set this too high and set themselves and people around them on fire.
Plus, once you sent your battery, they either discard it which is not ideal for the environment, or try to remanufacture it, which is very dangerous when it's done on a battery which wasn't designed for it, like ours
I am not enough of an expert to know if all this could work, but its got to be better than replacing an entire pack at a time to be worth trying
Most people aren't aware of how dangerous it is to try to "revive" a cell that got too low so this technology definitely comes with significant risks for user error.
So yes, the net current is supposed to be okay, but it’s not, and rather than responding individually to all the other comments I may as well mention that no amount of temperature monitoring will fix this. Temperature sensors don’t detect internal cell stresses that cause spontaneous failures.
We are also looking for bike-shop owners who want to train on our batteries (it can be learned in one hour or so) to get a new revenue stream by offering to repair and assemble our batteries!
As long as the controller is made sufficiently conservative, there is no fundamental problem: you limit the current according to the cell that heats the fastest and shut down once one cell is near depletion.
Maybe they have even gone a more aggressive route and build a balancing circuit that can route significant current around a low-capacity cell. Or maybe just charging logic to keep as many cells as possible in the 20-80 regime if they will be limited by low-capacity members anyway. There are so many options here.
If HN had profile pictures, mine would be a Clippy.
I don't have a good profile of e-bike owner behavior about maintaining their own equipment, but what I can say is fewer than 1/5 of e-bikes will stop on red at a 3-way intersection near me (when cars are stopped in the parallel lane, and pedestrians are crossing).
We also see a lot of riding on sidewalks, at speed, to bypass red lights and traffic on a major street here.
That said, the e-bike riders are often wearing helmets as they plow through pedestrians, so maybe their recklessness only extends to the safety of others, and they'll be conscientious about not lighting a lithium battery fire between their own legs.