New potential ebike battery product development

[tonytieger]

Tony from Voltphreaks here. We've sold many of our single cell 2 amp lifepo4 chargers here.

Our company primarily makes 12V car starter batteries for the high end racing market, to save weight. This market obviously has different requirements than the ebike market. I'm currently using two of our 12V batteries on my ebike (an Electrec), but obviously an eBike doesn't need 1200 cranking amps.

We're wondering if there would be any interest in influencing the design of an eBike battery that we're thinking of selling. It would be similar to what's currently out there, except more expensive unfortunately. Would have under and over voltage protection, and over-temperature protection. Protection would be via active cutoff of the pack, preventing damage. 60A continuous, 150A peak discharge. A 48V, 15Ah battery would cost over $1000. So feel free to PM/reply here with any feedback, as ideally we want to make something that people can actually use and welcome any feedback from this forum, as people here are much more knowledgable and experienced with eBikes than us!

- Tony

 

[Doctorbass]

Tony from Voltphreaks here. We've sold many of our single cell 2 amp lifepo4 chargers here.

Our company primarily makes 12V car starter batteries for the high end racing market, to save weight. This market obviously has different requirements than the ebike market. I'm currently using two of our 12V batteries on my ebike (an Electrec), but obviously an eBike doesn't need 1200 cranking amps.

We're wondering if there would be any interest in influencing the design of an eBike battery that we're thinking of selling. It would be similar to what's currently out there, except more expensive unfortunately. Would have under and over voltage protection, and over-temperature protection. Protection would be via active cutoff of the pack, preventing damage. 60A continuous, 150A peak discharge. A 48V, 15Ah battery would cost over $1000. So feel free to PM/reply here with any feedback, as ideally we want to make something that people can actually use and welcome any feedback from this forum, as people here are much more knowledgable and experienced with eBikes than us!

- Tony

I have just a question Tony,

The battery you build seems using A123 cells (they are the best!), but what kind of BMS circuit do you use to carry 1200 CCA and to be able to cut it on over or under voltage detection??.. that would need a large mosfet array!!

but only 4 cells in serie had been able to boost my car last winter at -20 degree C !

I built mine with 4s4p here last year:..http://www.youtube.com/watch?v=JgJ-BHUXQeQ

As for the help, i'm sure people here will accept to pârticipate to that project... we already developped or worked on many BMS and ebikes circuit projects!


Doc

 

[tonytieger]

Yes 1200A isn't suitable for MOSFET use! We're using a custom relay, it's actually pretty expensive. But this wouldn't be needed for the ebike pack fortunately!

- Tony

 

[dogman dan]

A triangle shaped pack complete with a hard shell case would be appealing to a lot of folks that want to carry the pack there. Others would really like a split pack to go in panniers on the rear rack. Parallel and series connectability too. And unfortunately, with even the best cells, somewhat easy cell replacement would be better than a pack that is all spot welded. Maybe at least, spot welded cells to make each 15 ah 3.4v cell, but then use a wire to connect each of the 16 cells. That way you could buy a replacement cell and only have to connect a wire to install it. That kind of setup would make funny shapes easier to make too.

 

[lfairban]

Lower Price would be great!

Actually $1K for a 48V/15Ah would be close to the current market value for Lithium batteries.

Not all ebikes can use a 48V battery. Most of the ones sold right now specify 36V, and overvolting tolerance varies. My 8yo bike and the low end zips use 24V/10-12Ah. If someone would make a $100 12V/10Ah drop in replacement for the SLAs (2x per bike), lots of people would convert when the original batteries wore out. But that is 40% below the price you specified. No one this side of China has 24V/10Ah as low as $300. I think a lot of people would buy a nanophosphat that size for $350 or a 36V/10Ah for $500.

Thanks, and good luck.

 

[boostjuice]

-A triangle shaped pack complete with a hard shell case
-split pack to go in panniers on the rear rack and distribute weight evenly L>R . Parallel and series connectability too.
-threaded ends on cells to aid in cell replacement.

X2 yes yes yes!!

 

[youreaspeedemon]

Tony from Voltphreaks here.
I'm currently using two of our 12V batteries on my ebike (an Electrec),
We're wondering if there would be any interest in influencing the design of an eBike battery that we're thinking of selling.
- Tony

If you build it they will come! I mean buy it (myself included) it has to have high C rating from your website that obviously should not be an issue
no bms interference with Amp spikes 80A-100A or so and 60A continuous, lvc cutout and over charging protection
the ability to charge it in a short period of time, including cell balancing of course
smaller packs in series to build a larger pack would be ideal for a lot of people

Don't forget about higher voltages as well, there are a lot of folks out there looking for 72V and 96V packs, I have an X5 and would love to get some solid lifepo4's to the tune of 96V. Series connection of smaller modules say 12V or 24V packs allowing a setup up to 96V would allow people to place the batteries in ideal locations for weight distribution. If your 12V VPH700 14Ah batteries were $200-250 I would buy 8. As mentioned above $1000 seems to be about right for current market for a 48V pack, but why place a product in the current market, build a superior product with a lower price and you would make tons of money and force the lifepo4 revolution that all of us have been waiting for.

 

[MitchJi]

We're wondering if there would be any interest in influencing the design of an eBike battery that we're thinking of selling. It would be similar to what's currently out there, except more expensive unfortunately. Would have under and over voltage protection, and over-temperature protection. Protection would be via active cutoff of the pack, preventing damage. 60A continuous, 150A peak discharge. A 48V, 15Ah battery would cost over $1000. So feel free to PM/reply here with any feedback, as ideally we want to make something that people can actually use and welcome any feedback from this forum, as people here are much more knowledgable and experienced with eBikes than us!

- Tony

Hi Tony,

I think you need more Voltage and Ah choices. A 15Ah A123 would have a much higher output than 60A continuous, 150A peak discharge? What chemistry or what cells do you plan to use? For A123 or similar quality cells the price sounds reasonable.