MIT Startup Seeks Feedback on "Smart" Charger for E-Bikes

cyberpika

cyberpika

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Hello everyone! So excited to join the community! We’re a Denver-based startup founded by MIT alumni, trying to design an affordable & "Smart" charger for ebikes. While e-bike technology has evolved rapidly, chargers remain outdated—often clunky and lacking smart features.

If you have a few minutes, we really appreciate your help to fill out a quick survey here: https://www.cyberpika.com/pages/smart-charger-user-survey

Otherwise, feel free to drop your thoughts in the comments. Some questions are:
  • Are you interested in a feature that can programmatically change the charging percentage (say, 20% to 100%)? why?
  • Are you interested in a feature that can programmatically change the amp and charging speed (say, 2A to 3A)? why?
  • What other "features" do you want to make your charger "smarter"?

Thank you!
The Cyberpika Team
 
  • Are you interested in a feature that can programmatically change the charging percentage (say, 20% to 100%)? why?
    • Yes, make one for 60v systems please.
  • Are you interested in a feature that can programmatically change the amp and charging speed (say, 2A to 3A)? why?
    • Yes, make as high as 5 amps.
  • What other "features" do you want to make your charger "smarter"?
    • Please design with built in discharger circuit that will discharge to 65% and shut off.
 
Hoggdoc said:
  • Are you interested in a feature that can programmatically change the charging percentage (say, 20% to 100%)? why?
    • Yes, make one for 60v systems please.
  • Are you interested in a feature that can programmatically change the amp and charging speed (say, 2A to 3A)? why?
    • Yes, make as high as 5 amps.
  • What other "features" do you want to make your charger "smarter"?
    • Please design with built in discharger circuit that will discharge to 65% and shut off.
Click to expand...
I made some similar comments:

  • For charge level presets, I like 20% (for shipping), 50% (for storage) and 80 or 100% for charge.
  • I like the options to discharge to 20 or 50%, though this will make the device bigger and discharging will take awhile.
  • It should be UL Listed
  • Simple LED display is fine; no smart phone app or fancy display is needed in this case
  • Rate of charge options could be risky. A small pack with 1P configuration (no parallel cells) would not be safe to charge at 5 or 8A, where a 3P pack would not have a problem with this at all.
  • Selectable voltage is a great feature, but will be for advanced users only
One I forgot to put in is to accommodate different jacks on the battery pack. For example, Trek/Electra use one. There's the old fashioned concentric one. Maybe do the most common 3 designs?

Our wish list is going to make for on expensive product though, compared to just a simple digital timer that we could plug our cheap chargers into. ;-)
 
I finally gave up trying to find a discharger and designed my own. It uses two GRIN TECH discharge resistors, a X90 anti spark connector, a volt/amp meter and custom connector for my battery output. My battery is 60v so Grin said I needed to use two of the resistors in series to get about 4.5 amps load. I all works fine except I have to monitor it more than I like because there is no alarm or auto cut off for the system.
 

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Hoggdoc said:
I finally gave up trying to find a discharger and designed my own. It uses two GRIN TECH discharge resistors, a X90 anti spark connector, a volt/amp meter and custom connector for my battery output. My battery is 60v so Grin said I needed to use two of the resistors in series to get about 4.5 amps load. I all works fine except I have to monitor it more than I like because there is no alarm or auto cut off for the system.
Click to expand...
Nice vintage tool box you got there!
 
The ultimate charger would be fully programable with out any stinking APP, yet it could use one for those that want APP controls. Must be able to set charge voltages over a WIDE range fully user adjustable at least up to 100+ volts . It needs to be able to charge as slow as a half amp and go up as high as 25 amps. On higher voltage batteries the amperage will have to be cut back some or you will need the ability to use either 120VAC or 240VAC. Bigger and bigger batteries are coming. Should work with ALL types of Li batteries and the more other types the better BUT LifePO4 and L-ion are a must! Keep it as small, lite and quiet as possible!
 
lol, biggkidd is trolling, but yeah, charging to 80% for battery heatlh would be the most useful feature. Otherwise multiple voltage settings in one charger would be real nice for folks who ride multiple bikes with different voltage battery packs.
 
BiggKidd said:
No not trolling everything I said is currently possible with our tech! Just look at a bench top power supply.
Click to expand...
What's NOT possible is to accomplish all that without subjecting the manufacturer to an acceptable level of liability or at a cost at which it will sell.
 
I don't see why I mean look at a modern bench top power supply. The one I have works from 0.01- 5A and from 0-60 volts. It was cheap to boot and works very well. I've used it for all sorts of crazy stuff. BTW it's also very lite and fairly quiet and not very large either.
 
Hoggdoc said:
I finally gave trying to find a discharger and designed my own. It uses two GRIN TECH discharge resistors, a X90 anti spark connector, a volt/amp meter and custom connector for my battery output. My battery is 60v so Grin said I needed to use two of the resistors in series to get about 4.5 amps load. I all works fine except I have to monitor it more than I like because there is no alarm or auto cut off for the system.
Click to expand...
I think you and I may have discussed this privately, but my own setup, based on the same components, was made more or less fail-safe by adding a 30-minute residential-grade timer into the circuit. Being limited to only 30 minutes, it can't overdo the discharge even if I forget myself and overcrank the knob.

Its far from precise but it keeps my battery from draining to an unsafe level. My single unit draws about 7 amps. I only use it if I have charged to 58.8v just before a ride, and then cancel the ride.

Worth noting: Temperature on this load resistor gets up to around 500 degrees when letting all that power pump into it. Hence the brick. This thing will leave scorch marks on some types of cement. Particularly painted garage floors.

20240219_094009[1].jpg
 
BiggKidd said:
I don't see why I mean look at a modern bench top power supply. The one I have works from 0.01- 5A and from 0-60 volts. It was cheap to boot and works very well. I've used it for all sorts of crazy stuff. BTW it's also very lite and fairly quiet and not very large either.
Click to expand...
Well, in terms of liability, if you had a 36 V battery and you accidentally left the power supply set to 60 V and walked away, you would start a fire in your absence if the BMS in the battery was not very robust.

In terms of cost, even that "cheap" power supply costs a LOT more than these laptop-type power bricks that only do one output scheme.
 
If the user screws the pooch then that's their fault not the tool makers! Just the same as guns don't kill people, people kill not guns.

I can see your point believe me. It's the nanny state we live in with big brother keeping an eye on all, things should have never gotten this far. What ever happened to owning the responsibility for your actions? Not you specifically the general population!
 
The Grin Satiator does multiple voltages and current rates already. And it has a user interface that lets you input whatever voltage and current you want up to the unit's current limit. I have one that will go up to a 96v pack, and 5a. So its capable of pumping out a buttload of power. But its $300+.

A decent quality 60v lab power supply is in the $100 range. Still not cheap. And does not have the kind of reliability that would justify that $100 price. Two of my three lab power supplies have died. One of them almost as soon as I put it into use. The other one after a couple of years.

A voltage+current adjustable Mean Well is about half that and has an MTBF in the ballpark of 200,000 hours. None of my Mean Wells have failed or exhibited any kind of wonkiness..

So what these guys are selling will have to be better than these already long-since-released - and commonly used - products.
 
CrossRoads said:
lol, biggkidd is trolling, but yeah, charging to 80% for battery heatlh would be the most useful feature. Otherwise multiple voltage settings in one charger would be real nice for folks who ride multiple bikes with different voltage battery packs.
Click to expand...
Luna cycles in Southern California has chargers that are capable of charging at 80, 90 and 100%. Some are even adjustable with regards to the amount of amps the chargers putting out
 
Hoggdoc said:
Luna cycles in Southern California has chargers that are capable of charging at 80, 90 and 100%. Some are even adjustable with regards to the amount of amps the chargers putting out
Click to expand...
I had three of those fail on me. The problem was they did not cut off at the required voltage. They were 52v models. One day I came down from my office into my garage and saw the charger still going at 59.5v. For the peanut gallery: 58.8v is 100% charge on a 52v pack.

That sounds horrifying (and it kind of is) but the BMS would have hopefully cut the charge off at around 60v which is 102%, so its not THAT bad. But I was down to my last level of defense with the BMS.

Luna was great about warrantying the chargers, and in one case spent a bunch of time with me trying to diagnose it. But after the third failure I decided this wasn't the right path to go down and thats when I went to the Mean Wells.

Later that same year Eric Hicks of Luna went on record on social media saying his company was going thru hell trying to find a reliable manufacturer for his chargers. That was many years ago so hopefully they settled on a long-term reliable partner. But since I switched I have never had a failure on a charger, and I have a half dozen of them, ranging from 185w to 480w units, some of which are permanently mounted onboard a bike.
 
It sounds to me like what is really needed is an external programmable BMS (charge controller?) to work with a basic adjustable bench power supply.
Just connect it to a current source and add the appropriate battery cable and it’s off to the races.
As the power supply is the most frequent failure this would let you just replace the source and continue using the charge controller.
 
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