Best watt hours per dollar in lithium - CALB, headway, tSky?

So i'm looking to build an ultra long distance cruiser eBike using an xtracycle platform, and space / weight is no longer at a premium, but a 100 mile range at 30mph is needed ( 3-4kWhr )

RC Lipo is out of the question. I love RC Lipo, but do not want that much of it hanging around, especially with having to deal with paralleling so many cells etc to get 40-100AH.

I've looked at a few of the big lifepo4 cells, 50-100AH and above, but can't come up with which is best.

Any opinions?

neptronix said:

I love RC Lipo, but do not want that much of it hanging around, especially with having to deal with paralleling so many cells etc to get 40-100AH.

Any opinions?

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Buy my PCBs and solder kits Nah seriously though, if you want watt-hours, try to keep your paralleled cells to a minimum. As Kyle has found out, the more 5Ah cells you have paralleled the more points of failure you will have. I think paralleling 5Ah cells is good up to about 25 Ah, meaning a 4 kWh pack would have to be 160 volts.

I'd say go for A123s if you want the watt hours.

This might help.

https://docs.google.com/spreadsheet/ccc?key=0Al-9VZS5gw_udFQwTTlCdXBFRUo0VVloa3dreVlJeEE

Aside from the 4S Turnigy hardcase packs, which have been quite elusive, the lowest $/Wh I've seen is the Sinopoly's at ~$0.36/Wh or A123 M20's if you can get them for $23.30 or less. Personally I like the large format prismatics for simplicity of construction, but they're not so good on volumetric density or high discharge levels.

thankx x88x, that spreadsheet was helpful. You're very right about the sinopoly cells, and there are new 60AH cells that are a bit lighter and smaller out now. I knew the headways were a little expensive but it didn't occur to me how much more expensive they were 'till i saw the spreadsheet.. damn!

Low C rate, but that can be dealt with on an eBike that will only draw 1C peak. I see how these could be sag-beasts in a car.

The best bang for the buck for large pack is the 7s3p from VictPower: http://endless-sphere.com/forums/viewtopic.php?f=14&t=38901

It is so cheap I was thinking about buying a pack for my bike (but I wouldn't know how to re-strip the cells to use them for my bike :lol: )

This seller is however not very trustworthy

neptronix said:

thankx x88x, that spreadsheet was helpful. You're very right about the sinopoly cells, and there are new 60AH cells that are a bit lighter and smaller out now. I knew the headways were a little expensive but it didn't occur to me how much more expensive they were 'till i saw the spreadsheet.. damn!

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Yup, that'd be the LFP60AHA(B) cells. I almost went with those for my motorcycle...unfortunately they were still too big for the capacity I need. Look like nice cells though. Best density I've seen for sub-100Ah big prismatic cells.

Hi,

cwah said:

The best bang for the buck for large pack is the 7s3p from VictPower....

This seller is however not very trustworthy

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Why do you say VictPower is not trustworthy?

Thanks!

Look at the thread I linked, you can see problem for a lot of buyer and how Victpower "help" them

cwah said:

Look at the thread I linked, you can see problem for a lot of buyer and how Victpower "help" them

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To be fair, I stopped paying attention to that thread a long time ago out of sheer exasperation, but most of the "problems" I saw people have sounded like standard Chinese trading house business practice to me (bargaining prices per individual, different salespeople using same front, little warranty, little technical knowledge of product, etc).

Tempting to say buy several 48v 20 ah pings. I would if the requirement was 100 miles at 20 mph. But it's true, to carry 4kw, you don't want gobs of 5 ah cells parallelled and series connected by solder. You want each 2k or so of 3.7v to be a thing you can bolt in when one needs replacing.

I'd say don't get so hung up on the price that you completely ignore practical considerations, such as how do you replace a bad cell. I'd call 20-40 ah hardshell lifepo4 a pretty practical choice. Perhaps a 60v 20- 40 ah pack on each pannier rack?

I'd also advise to not get so hung up on range at 30 mph, that you build yourself an excessively heavy and cumbersome bike. In the west, you may well ride routes that have zero plugs for 100 miles. But most will have something you can get a charge from somewhere every 50-70 miles. I'd build for 60 mile range at 30, and ride it slower on the rare occasions that you can't catch a charge mid ride. I'd carry 40 ah of 60v as an absolute maximum. Why not 48v? because you'd be better served by using a slower winding motor. Such as the pies you own now. So you'd need more than 48v to hit 30 mph I think.

For sure a good longtail can carry amazing weights. That's why I built one, fantasizing I could get away from work for a month of touring NM and CO in summer. But that doesn't mean the longtail won't ride much more comfy with 50 pounds of battery than it will with 100 pounds of battery.

Plus there is a attitude difference with me from many. When I ride a tour on the weekend, I want to ride 20 mph or even less. I've seen these roads in cars at 30-60 mph many many times. It's amazing how I never saw them at all, till I rode them on a bike at 15-20 mph. At 30 mph, I'm just watching the road surface for debris. That's pointless to me.

On tour, the point is not getting there, it's being there. Had the same problem backpacking. Carrying 50 pounds, all you saw of the wilderness around Silverton and Durango was your boots. The cure was to stop trying to get to the trout lake fast. Stop and look every 100 yards, and don't have get there itis.

Excessively heavy and cumbersome is not as much of a problem here. Lack of range anxiety would be key

Yeah, ping packs are going to cost me $644 per kW-hr. Being made out of 5AH cells is a real downside. Actually pretty much every pre-built pack is gonna be major $ due to the cost of the BMS and charger included.

I am wary of the A123 20AH cells due to their source and history. They are ideal in every way, being around 125-130wHr/KG, high C rate, and decently priced. But i would not expect them to deliver full cycles or lifespan - after all, why are $50-$60USD retail cells being sold at less than half of that? doesn't seem right to me. Then there is the tab welding issue, and i have not seen a really good way to handle that yet.

As for the motor, i am not even going to deal with hubs. A chain driven motor with an overspecced power rating for the speed i am going will be used, to provide the best efficiency from minimal copper heating. When you have an xtracycle or yuba mundo, you can hide said motor behind the panniers in the rearest triangle. Constant upper 80% efficiency should be possible.

Not exactly cheap but what about FFR Trikes Dow Kokam's? They had/have large formats available and most the money appears to stay here in USA. That's how I would probably go for building packs larger than 1kWh.

Ykick said:

Not exactly cheap but what about FFR Trikes Dow Kokam's? They had/have large formats available and most the money appears to stay here in USA. That's how I would probably go for building packs larger than 1kWh.

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Can you actually buy those separately? I'm not seeing anything about getting just the batteries on their website.

Ykick said:

Not exactly cheap but what about FFR Trikes Dow Kokam's? They had/have large formats available and most the money appears to stay here in USA. That's how I would probably go for building packs larger than 1kWh.

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$1000/kW-hr is almost 3 times the price of the lifepo4 i'm looking at. Nice cells, but these do not fit the requirement. You also get the same tab soldering issue as with the 20AH A123's.

They are more ideal for another kind of project.

x88x said:

Ykick said:

Not exactly cheap but what about FFR Trikes Dow Kokam's? They had/have large formats available and most the money appears to stay here in USA. That's how I would probably go for building packs larger than 1kWh.

Click to expand...

Can you actually buy those separately? I'm not seeing anything about getting just the batteries on their website.

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Best check with FFR Trikes but Mar 31 they informed me Michigan warehouse had 16Ah HR in stock ready to ship.

neptronix said:

$1000/kW-hr is almost 3 times the price of the lifepo4 i'm looking at. Nice cells, but these do not fit the requirement. You also get the same tab soldering issue as with the 20AH A123's.

They are more ideal for another kind of project.

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Why solder? I figured more of a clamp termination... But yes, very expensive on surface but once I considered C rate, longevity and supporting US business, these were the last on my list.

Ykick said:

Why solder? I figured more of a clamp termination... But yes, very expensive on surface but once I considered C rate, longevity and supporting US business, these were the last on my list.

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Yeah but are you buying 3-4kW-hr of battery to go 100 miles or over? At that point, a 1C battery is perfectly adequate. I would run the battery at under 0.5C continuous.

Longevity? well, lifepo4 is pretty well known for longevity. Yeah it's heavy and big..

I cannot justify $3,000-4,000 for an electric bike battery. $1,000/KW-Hr is double what big car companies pay for their cells..i i don't care how good the batteries are at that price point.

I understood that Victpower is making their own cell. They are also cheaper than ping and can make your own pack. I've been quote 550usd for a 20s pack from Victpower. About the same price from OSN power. So it's about 0.41$/wh.

Ping is heavier and at 0.50$/wh. You still prefer Ping? What can't we pay for peace in mind :lol:

With a battery that big you'd never need a bms and you'd never need to balance it! Talk about reliability. Charge to 3.45v and discharge to 3v and that battery will last a decade before it starts to fade. Talk about a mad max ebike.

I'm thinking 16s30ah lifepo4 is all you'd ever need. I ran out of juice all of once with my 48v20ah ping and it was when I first got it. I'd ride anywhere with out having to worry.

I'm thinking some TS batteries on the foot pads of the xtracycle would be easy for you to build and wouldn't interfer with the usage of the bike.

The real trick to not worrying about range anxiety is to have an on board charger that is easy to use and safe to use anywhere. TBH, 90% of the places you will travel will have some where to charge.

I'd get one of the meanwell LED power supplies. They have built in current limiting and voltage tuning, AND they are waterproof. Zip tie it to the bottom of your rack and keep the cord in the bag. I wish I could do this with my new bike, but they don't have them in high enough voltages.

I've been very happy with the GBS 40AH cells in my motorcycle. 4000 miles and no degradation, no issues at all.

We have a local source in Boulder, so if you wanted you could pick them up at good prices:
http://www.evolveelectrics.com/Batteries.html

They also have the other major brands of large capacity cells.

Cheers,

Consider 20A thunderskys from elitepowersolutions.com If you have any questions Im your guy.

Auraslip, i think you understand my idea best! I would definitely be able to go without a BMS. If i go 12S - 14S, i could just use the hyperion 1420i and treat it like it was a big lipo pack.

Mad max ultra mileage is what i'm looking for. Tired of having to turn back after 20 miles of joy riding. I want something that i could charge up and never worry about.

Giant pannier batteries will work. 100lb of batteries? That's what an average joe xtracycle/Yuba mundo can do without breaking a sweat or worrying about the frame flexing too much. As a bonus, i could later use said batteries as a solar storage array that would easily fit in an RV.

You're right about a charger. That helps. Are you talking about using the meanwell LED power supply as something you can put in series with some power supplies to make yourself a nice current limited ubercharger, auraslip?

auraslip said:

With a battery that big you'd never need a bms and you'd never need to balance it! Talk about reliability. Charge to 3.45v and discharge to 3v and that battery will last a decade before it starts to fade. Talk about a mad max ebike.

I'm thinking 16s30ah lifepo4 is all you'd ever need. I ran out of juice all of once with my 48v20ah ping and it was when I first got it. I'd ride anywhere with out having to worry.

I'm thinking some TS batteries on the foot pads of the xtracycle would be easy for you to build and wouldn't interfer with the usage of the bike.

The real trick to not worrying about range anxiety is to have an on board charger that is easy to use and safe to use anywhere. TBH, 90% of the places you will travel will have some where to charge.

I'd get one of the meanwell LED power supplies. They have built in current limiting and voltage tuning, AND they are waterproof. Zip tie it to the bottom of your rack and keep the cord in the bag. I wish I could do this with my new bike, but they don't have them in high enough voltages.

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The meanwell LED PSUs are made for outdoor use and can go up to 56v! perfect for 12s lipo and 16s lifepo4

True, but maxing out at 320w-240w is very unfortunate. pretty poky.

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2141878_-1

What about one of these? 22A at 12v.

http://www.jameco.com/Jameco/Products/ProdDS/2141878.pdf

Only adjustable by 3 volts, but i bet you can mod it to go downwards.
Spendy, but throw a few server power supplies in series and you could almost have a breaker trippper..

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2115098_-1

They also make a cheaper 16A/12v version.

If i can find some cheap, small size power supplies to run in series, then these would rock.

It wouldn't be weatherproof, but having 950W or so of charging power hanging around would be nice. Could get 1/3rd of a charge in an hour. hm..

weather proofing is the deal maker for me. on my latest bike with an alloy shell charger in the battery box it gets quite hot. I'm thinking I might have to ventilate it! And that would kinda do away with the waterproof purpose. It'd be a huge PITA to rig up a theft proof, waterproof charger using server power supplies. And also I think they're a bit over kill. I'm only pushing my units at 1/6th of their rated power right now!

The meanwell things are around the price of the alloy shell chargers, and they're probably much high quality and smaller too. Yeah they're slow, but honestly most places I go I go for more than an hour. So if I can put 300 watt hours into the pack I've pretty much put back the amount of power into the pack I've used up getting there. If you absolutely had to have tons of power that was bullet proof, I'd say run 2 of them in parallel.

That's how I'd do it, but then I'm more of a reliability/ease of use based guy. If you want to lug around a 20lb, 1500w alloy shell charger then I can see how it might be useful.

You have a point. I see what you're getting at. 300 watt hours is a lot of range if you slow-train it home at 15-20mph. Where i am moving, there are rest stops where you have water and electrical outlets in various places. Not so much in Colorado. I think there will also be EV charging stations eventually as well. Good time to sit down with a book, iPad/tablet, or something else and chill for a moment.

You're right, i should pick one up due to it's weatherproofiness. I could plan said 100 mile trips around dinner or lunch time at a place that is bike friendly.