A fresh notion? Same Ah, but multi shaped LIFEPO4 pouches?

[cycleops612]

I hope this is ok, but i thought this repost an fyi? for others also (i cant find any other mention of it here & I have not heard of it):

~" I think i have an idea on the matter for custom shaped pouch cell paks, better as a separate post, but briefly, u have to use all the same size cells- right? Yeah, but they dont have to be the same shape. So e.g., by combining square/rectangular/triangular pouches of same capacity and maker, great density and flexibility in the shape of the pak could be achieved. If the pouches contain the exact same quantity of the exact same brew, they are the same."

Further:

The problem worsens with high voltages. 48v is 16 lifepo4 pouches. Woo.

There is the option of smaller cells, like 5ah pouches, in parallel banks, yielding both hi c rates and more flexible shaped paks, but i distrust this.

Give me the simplicity of the biggest cell size for the job, in series to get the required voltage and sufficient c rates for an ebike. Easy BMS, charging and diagnostics. Shaped pouches would help achieve this.

 

[nutnspecial]

I think it would be nearly counterproductive to reliably engineer different shaped cells in that way to match capacity and capacitance/resistance, but like and agree with larger format cells when they can be used/applied.

 

[Toorbough ULL-Zeveigh]

http://www.gmbattery.com/product/showproduct.php?lang=en&id=520

Main applications are;Communications equipment:  mobile phone, PHS phone, Bluetooth cell phones, walkie-talkieInformation equipment:  laptop computers, PDA, portable fax machines, printersAudio-visual equipment:  digital cameras, camcorders, portable DVD, VCDOthers:  electric bicycles, miner's lamp

 

[cycleops612]

the matter has has been on my mind, given this post

& the more it seemed that, ebikes are magic, but where the hell do you put a big lump of a battery, other than between the riders legs, which is fraught, given pedaling.

frame designs have made no concession to this fundamental variation from normal requirements of a pedal bike.

fyi:

look ma, no seatpost

http://www.pedegoelectricbikes.com/shop/ford-super-cruiser/

interesting frame concept, it looks heavy, but not too bad

"WEIGHT
Bicycle Only – 53 lbs (24.1kg), Battery Pack – 9 lbs Total Weight – 62 lbs"

New design to me. Do we really need the seatpost tube with modern materials and methods? It looks springier?

If front frame tubing curved to hug the front wheel, a more usable battery well would form in the frame.

as a lifepo4 pouch pak prospective buyer/upgrader, assuming you can orient them any way? (could someone answer this pls?), the most problematic dimension in the conventional brick shaped paks, is width (between your knees space), which is voltage dependent.

most pouches - 10/20 amp say, are 1 cm thick, so 8cm for 24v, 12cm for 36v etc. add at least 50% for packing? it gets tight, even assuming there is a well for a regular shaped brick.

It may seem the cart before the horse, but 24v has an advantage here. 8 cells is a thinner shape. 24v at 20 amps is good for a 500 watt~ per motor, which is ok for most. I prefer to get my watts from as few, & as large cells as possible.

I know about saddle bag custom batteries, but besides them? Its another issue.

 

[parabellum]

18650 cells? Make shape you want. The economics of making different shapes of cells is just against getting e vehicles wide spread, mass production is the way to go. I personally have more space on my bikes then money to buy "conventional" batteries to fill them.

 

[cycleops612]

18650 cells? Make shape you want. The economics of making different shapes of cells is just against getting e vehicles wide spread, mass production is the way to go. I personally have more space on my bikes then money to buy "conventional" batteries to fill them.

except in my view they suck, which is a long separate argument, but i am confidant the majority in the know will become disillusioned with them also . way overrated, like the 20% of capacity you cant use, for starters (add 20% to their weight and cost when comparing, and they dont look so hot). For me, self destructing if not babied during storage is a deal breaker alone.

But lets not go there here.

Of course (i hope not a repeat), makers can and do similar, simply using smaller pouches & banking them in parallel - a 10 ah pak made from 5ah pouches e.g., but as i said, i intuitively prefer the largest pouches possible, even if it means a lower c-rate (unless i had a big need for fast recharge). 2-3 c is fine for my ebike needs.

In short, we are trying to fit a regular shape units into an irregular shaped well, so if the units were identical in content, but variously shaped, assemblages can more easily be made to fit, or be better located on the bike.

I think it would be exellent marketting for a pouch maker.

 

[cycleops612]

https://howellenergy.en.alibaba.com/product/485477177-214095802/36V_15Ah_lifepo4_battery_pack_with_triangle_shape.html

its a pak (made from 5ah cells)

fyi. 5C is interesting.