When money is of no concern:Super Quality Batteries

Whats the best battery out there for ebikes. I do not mean reasonable, I mean THE BEST if money was not a factor. I am talking about a battery that might cost anywhere from 2,000 to 20,000 dollars. Does a super high end exist and if so, are you getting diminishing returns for your money?

I want my bike to be able to go at least 100-200 miles (throttle only) per charge @20mph. This is a dream of mine to ride my bike across the country, have enough juice for interstate travel once a day, and have a place to charge during night/partial charges during the day.
So It may not necessarily be capacity and energy density but instead be a faster charging speed for a shorter range battery.

The highest energy density possible & lowest weight/size would be the way to go.
And you'd want 100-150AH worth of it.

As long as it had better than a 0.5C discharge rate, you'd be doing fine. You'd not be pushing 50 amps anyways, definitely 30 or less to maintain 20mph. ( 0.5C on a 100AH battery is 50 amps... )

What you're looking to do is take Tesla Motors' approach and use a super high quantity of a lower C rate battery to get the smallest size and weight.

The 'energy' based Dow Kokam cells may be what you are looking for. I don't think anyone can get their hands on the super high density Panasonic 18650s just yet. Other low C rate NMC options should be explored as well.

neptronix said:

The highest energy density possible & lowest weight/size would be the way to go.
And you'd want 100-150AH worth of it.

As long as it had better than a 0.5C discharge rate, you'd be doing fine. You'd not be pushing 50 amps anyways, definitely 30 or less to maintain 20mph. ( 0.5C on a 100AH battery is 50 amps... )

What you're looking to do is take Tesla Motors' approach and use a super high quantity of a lower C rate battery to get the smallest size and weight.

The 'energy' based Dow Kokam cells may be what you are looking for. I don't think anyone can get their hands on the super high density Panasonic 18650s just yet. Other low C rate NMC options should be explored as well.

Click to expand...

I was actually using the Panasonic NCR18650A 3100mah cells you are talking about for the 102 miles race last Saturday. The weight to watt hours ratio was very impressive. 102 miles for less than 17 LBS with about 1534 watt hours was used out of total capacity of 1927 watt hours.

See the story below:
http://endless-sphere.com/forums/viewtopic.php?f=3&t=35124&hilit=lyen&start=75#p533763

Thanks for chipping in Lyen; i believe those are the last generation cells that the Tesla Roadster used, am i correct?

Where did you get those cells, btw?

If money was no concern, and I wanted to go on long trips, I would do the following:

1. Get one of those "Bob" bike trailers and stuff in it:

2. 48v of GBS 100AH cells with BMS, system monitor from: www.elitepowersolutions.com.

3. This 4KW charger allowing you a full charge in 90min off a J1772 charging station: http://www.bmsbattery.com/alloy-shell/377-alloy-shell-2000w-lifepo4li-ionlead-acid-battery-ev-charger.html

4. The J1772 to 240Vac adapter cable from: www.modularevpower.com

Check out: plugshare.com. California has J1772 charging stations everywhere and more are popping up everyday.

Good luck,

You may want to talk to this guy (although it's not, strictly speaking, a battery):

http://blogs.discovery.com/good_ide...ilding-your-own-personal-nuclear-reactor.html

Cameron

Blueshift said:

Whats the best battery out there for ebikes. I do not mean reasonable, I mean THE BEST if money was not a factor. I am talking about a battery that might cost anywhere from 2,000 to 20,000 dollars. Does a super high end exist and if so, are you getting diminishing returns for your money?

I want my bike to be able to go at least 100-200 miles (throttle only) per charge @20mph. This is a dream of mine to ride my bike across the country, have enough juice for interstate travel once a day, and have a place to charge during night/partial charges during the day.
So It may not necessarily be capacity and energy density but instead be a faster charging speed for a shorter range battery.

Click to expand...

You want LG-chem cells from a Volt, or EIG cells from a Zero.

Wow. 100-200 miles per day - or 5 to 10 hours constant on the bike, or realistically, with breaks, a 7-12 hour day. That's quite a long haul, and that shapes part of my answer...

I think if I was building this bike, even if money was no objective, I would still be using common Lipos, and getting multiple high rate chargers so that I could make a significant difference even for a 15 minute drink and toilet break. And that's my other point - How long do you think you could ride for non stop? On my motorcycle, which was a sports bike, I could do about 2-3 hours tops, without a break. After that, I'd really want to stretch my legs, give my back a rest, and get off the bike for a good half hour or more. Even after months of push and electric bike riding, I find 2-3 hours is still my limit on my racer, though maybe a bit longer on my electric mountain bike, which has a better sitting position.

Why does this shape my answer? Well, if you're going to have to stop 30 minutes every 2 hours anyway, then you could do staggered charges. E.g. size the battery and the charger, so you ride for 2 hours, and draw down to 60%. Stop for 30 minutes and charge back up to 80%. Ride for another 2 hours and drop down to 40%. Charge for another 30 mins and go back to 60% etc. When you finally stop for the night, then top it back to 100%.

The thing I keep thinking is that more batteries = more points of failure + more weight + more aerodynamic drag. Yes, they're minor, but they do all add up and change the riding experience.

I know it's not a real answer to your question, but maybe it's a different way of thinking about solving the same problem.

RC Lipos are good. I picked zippy batteries for this reason - a 4.8AH 15C 6 cell pack weighs the same as a Turnigy 5AH 20C 5 cell pack - pretty good, but there are far better options out there.

What you will want is the lowest weight possible, that's why i recommend putzy NMC type stuff - high energy density at an extreme expense to power. Doesn't matter when you are running 100AH on a mild amp draw, not at all

SAFT makes some crazy cells for when money is of no concern

I already have a high quality battery. Its the same used in the famed Optibike.

I already have this...
36v 60Ah TS cells on a 36v 20a controller on a 20" wheel...
Average range on an average 20 mph is 120 miles..(Without charging or pedaling!)

Think 2 hours of riding.. (Trust me, no fun) thats 40 miles (20Ah) then charge for an hour with a 10a charger or 30 min with a 20a charger... (Currently at 50ah)
Go another 2 hours, thats another 40 miles.. (-20ah = 30Ah) and 80 mile
Down to 30Ah, charge another 30m-1hr. (Currently at 40ah) and you've gone 80miles..
Go another 2 hours (-20ah = 20ah) that's about 40 miles (Youre at 120miles)
Down to 20ah charge for another 30-1hr (Currently at 30Ah)
Go another 2 hours ( -20Ah = 10Ah) that's 160 miles!!
(at this point you don't want to ride anymore, TRUST ME ON THIS!!! - but if you're a glutton for punishment, charge again so that you have 20 Ah left and ride another 2 hours/40 miles.)

So total for the day is 8 hours of riding, 2-4 hours of charging for a total of a 10-12 hour day of battery and riding..
(Or for punishment 10 hours of riding and 2.5-5 hours of charging for a total of 12.5-15 hour day 200 miles)

Charge up overnight and start again..

I did the pure riding (With breaks every 30 miles or so) and no charging only ONCE in a 16 month period for 116 miles total round trip from west palm beach to ft Lauderdale to Miami to ft laudedale to Boca raton and back to west palm beach..
Total time?
Started at 6am, took in the sights (Miami) Starbucks (Miami, Ft l & Boca), brothers house (Boca), etc
Got home 10pm that night.
Won't be doing that again, any time soon.. (Unless, I get a better seat/trike/whatever).

My next long range battery will be 12s(43.2-44.4v) / 5p(66.5Ah) / (Qty:60)13.3ah NMC cells.. (total 2.88-2.95kwh)
That's approximately 35lbs. of battery as opposed to the 60+lbs of Thunderskys!

Should net me about 150 miles... If I wanna go 200 easily, I would go another 2p and have (Average) 43.8v / 93Ah or just a tad over 4Kwh!! For 48lbs of battery.. Still 12 lbs lighter than the TSs.

neptronix said:

Thanks for chipping in Lyen; i believe those are the last generation cells that the Tesla Roadster used, am i correct?

Where did you get those cells, btw?

Click to expand...

Yes, you are good knowing what they are.

I got the cells from my uncle who travels to 日本 from time to time. It was a pain in the butt to solder 168 cells together (7S24P). The weight without the tabs and solder, wires and tape was about the same as a 16 lbs bowling ball.

Great answers gang! There's quite a few ways to go about it I see.

How Safe are the Dow Kokam and Panasonic 18650s?. Do they have to be babied? anything Different from letting the BMS do its thing and checking voltages once in a while?

Blueshift said:

Great answers gang! There's quite a few ways to go about it I see.

How Safe are the Dow Kokam and Panasonic 18650s?. Do they have to be babied? anything Different from letting the BMS do its thing and checking voltages once in a while?

Click to expand...

Supposedly very safe.

With such expensive batteries one could afford to also get a state-of-the-art no worries BMS.

How awesome is Lyen? Basically is a fountain of information for the forum (always delivering photos that matter), gives his time delivering what in my opinion are the best controllers available (I only roll with Lyen's on my three ebikes).

You don't see Lyen creating random useless posts about Rollins or eating pussy

It is guys like Edward that make this the coolest website known to man. Hats off to you sir

Blueshift said:

I want my bike to be able to go at least 100-200 miles (throttle only) per charge @20mph. This is a dream of mine to ride my bike across the country, have enough juice for interstate travel once a day, and have a place to charge during night/partial charges during the day.
So It may not necessarily be capacity and energy density but instead be a faster charging speed for a shorter range battery.

Click to expand...

On second thoughts, perhaps what you really need is a an electric velomobile. Couple it with a trailer and some Lithium NMC batteries and you have a vehicle that you could spend long periods of time in without aches and pains. The velomobile alone would probable cost a minimum of $10,000 and that's before you add stuff like lights, heater/cooler etc.

http://www.lowtechmagazine.com/2010/09/the-velomobile-high-tech-bike-or-low-tech-car.html

Basically, the practicality of a velomobile boils down to infrastructure and driver awareness. If drivers are used to seeing plenty of bicycles etc. and the roads are good you will be quite safe.

the panasonic 3.1ah (greens) have to be the winner, they are about 243wh per kg.

surely that beats ANY other cell (that you can actually hold), welcome to hear about anything else (real) thats even over 200, lipos are around 150..

and you can get them off ebay -think it was an australian seller.

Joseph C. said:

On second thoughts, perhaps what you really need is a an electric velomobile. Couple it with a trailer and some Lithium NMC batteries and you have a vehicle that you could spend long periods of time in without aches and pains. The velomobile alone would probable cost a minimum of $10,000 and that's before you add stuff like lights, heater/cooler etc.

http://www.lowtechmagazine.com/2010/09/the-velomobile-high-tech-bike-or-low-tech-car.html

Basically, the practicality of a velomobile boils down to infrastructure and driver awareness. If drivers are used to seeing plenty of bicycles etc. and the roads are good you will be quite safe.

Click to expand...

What he said
~CrazyJerry

I understand the desire to be sitting low to the ground as a velomobile does, however, I would feel more comfortable in something that i had a better view in, but maybe similar to a velomobile like the drymer.
for 8-12 hours on the road I think that would definitely require a seat with some sort of back support and tilting back a bit to distribute the weight so you dont lose the feeling in your bum lol

Yeah, 8 hours (even total throughout an entire day) on a banana seat ain't the best thing for your back (or butt!)..
Good thing I'm in decent shape..

toolman2 said:

the panasonic 3.1ah (greens) have to be the winner, they are about 243wh per kg.

surely that beats ANY other cell (that you can actually hold), welcome to hear about anything else (real) thats even over 200, lipos are around 150..

and you can get them off ebay -think it was an australian seller.

Click to expand...

What about these?
3.7V x 4.2Ah = 15.54 Wh per cell
One cell is 47gram, so 15.54/47*1000 = 330Wh/kg.
Assuming a very conservative 2C discharge rate, these cells would provide 8.4 Amp per cell. With my 72V 90 Amp (2x45A) setup, I would need at least 10 cells in parallel. Hmm.

Price is not too bad as well: $ 163 for 36 cells = $ 4.528 per cell. For a 20S 10P 42Ah pack, that would be $ 905 with a weight of 10kg (same as my current 20S 3P 13.5Ah Zippy Lipo setup).

What am I missing here? Anyone knows the discharge rate of these cells?

Blueshift said:

Great answers gang! There's quite a few ways to go about it I see.

How Safe are the Dow Kokam and Panasonic 18650s?. Do they have to be babied? anything Different from letting the BMS do its thing and checking voltages once in a while?

Click to expand...

It's lithium cobalt dioxide. Same chemistry as RC lipo, only they replace all the conductive additives that give RC lipo minimal sag and an awesome C-rate with additional energy storage material.

They do fail in spectacular thermal run-away if you do to them the same things that causes RC LiPo to go into runaway.

They will not last 1000cycles of useful life.

When you use them in a remotely high-drain application, even 1C, you lose quite a lot of there energy in the form of voltage sag, which is lame. If you're making a pack for 200miles though, your pack should be large enough for a low powered bicycle to avoid most of this sag loss.

hjns said:

toolman2 said:

the panasonic 3.1ah (greens) have to be the winner, they are about 243wh per kg.

surely that beats ANY other cell (that you can actually hold), welcome to hear about anything else (real) thats even over 200, lipos are around 150..

and you can get them off ebay -think it was an australian seller.

Click to expand...

What about these?
3.7V x 4.2Ah = 15.54 Wh per cell
One cell is 47gram, so 15.54/47*1000 = 330Wh/kg.
Assuming a very conservative 2C discharge rate, these cells would provide 8.4 Amp per cell. With my 72V 90 Amp (2x45A) setup, I would need at least 10 cells in parallel. Hmm.

Price is not too bad as well: $ 163 for 36 cells = $ 4.528 per cell. For a 20S 10P 42Ah pack, that would be $ 905 with a weight of 10kg (same as my current 20S 3P 13.5Ah Zippy Lipo setup).

What am I missing here? Anyone knows the discharge rate of these cells?

Click to expand...

Those are nothing but scam. They buy rejected cells, put them in there own shrink wrap with whatever they like printed on it, and sell them to idiots. We've had folks on here buy a number of those types of cells to test, including myself, and it's always funny to cut away the shrink wrap, have the shiny end caps fall off, and revel some old 18650 that used to be tab welded into an old laptop pack, and you can still see where they ripped off the tab welds with pliars, put the new shiny caps on the ends, and shrink wrapped the random garbage cells with something that says 4000mAh, or 4500mAh, or whatever they think would be fun to print, I'm waiting to see some 10,000mAh shrink wrap on them.