Long Range EBikes - Can it be done

[chopper_elec]

Hey all,
I've been over the moon lately after my first "ebike" experience and I am wanting to eventually put a lot more effort and money into this interest/hobby.

I am using anchor boats at the moment and I am planning long term to go on some long distances rides, around 100km including the loop run back home. My bike is a chopper bicycle and I have a modified kids trailer with lots of space.

At the moment I am just using SLA 12v 12ah batteries in a 48v arrangement but long term i'd like to replace this with a 20ah lifepo4 battery.

I'm interested in your stories of the longer distance riding you've been able to achieve where you were mainly using the electric motor.

 

[Hillhater]

....I am using anchor boats at the moment but I am planning long term to go on some long distances rides,.

wot ??

 

[SamTexas]

I'm interested in your stories of the longer distance riding you've been able to achieve where you were mainly using the electric motor.

Not really a story, just some thing I do for fun. I have one ebike with a 14s16p recycled laptop batteries. 26Ah, 1,347Wh. 10Ah is in the triangle and 16Ah on the rear rack. Total battery weight is 23 lbs. With a one to one power assist (half power from me, half from the motor) the range is 130 miles (208 km) at 20mph average. About 90 km if I let the motor do all the work, at the same 20mph average speed.

 

[chopper_elec]

....I am using anchor boats at the moment but I am planning long term to go on some long distances rides,.

wot ??

its one of those days sorry

I'm using slas at the moment but want to keep the weight down and increase capacity considerably.

 

[full-throttle]

Not sure what your question really is.. if your aim is to ride 100km then you should prob state how many wh/km you are using. Dividing the 2 will give you the capacity of the pack. Does it make any sense?

Range is affected by how fast you go, how much you pedal, how much time the motor is in peak efficiency zone, ambient temperature (batteries don't like cold), aerodynamics, weight, tyres, road surface.. etc.. Pack capacity will also reduce with age.

 

[amberwolf]

Long Range EBikes - Can it be done

For starters you might wanna look up Kingfish and Justin_LE.

 

[dogman dan]

Boat anchors, doorstops, lead bricks.

Sure long range can be done, but doing long range at faster, say above 25 mph speeds is what gets tough. The faster you go, the more battery it takes to go far. At some point, carrying it becomes the real problem. Various solutions exist, carry more battery and be able to charge it fast for example.

100k, 60 miles is a pretty long ride, but not extremely long. I did few rides any much longer myself because I'd be numb enough in the butt to want off by 60 miles, and could generally reach another town in 60 miles. I always meant to do a 100 mile day, but never did. I think 70 miles was my longest day. I really liked about 50 miles, because I could ride faster on the capacity I had. ( two pings, 30 pounds of battery)

If you strictly ride slightly less than 20 mph, you will get 30 mile from one 36v 20 ah, or 48v 15 ah lithium battery. About 650 watthours. So two of those, or a charge halfway if there is a town, and you are good for 100k. Personally, I found aiming for 18mph worked well, since I'd constantly let speed creep up. Helps if it's very scenic, if you must ride that slow.

Long range while still using the lead would be harder. Lead doesn't like faster charging, but if the pack is huge charging at 5 amps would be possible. You'd have to stop to charge more often than with 30 pounds of lithium.

 

[chopper_elec]

Thanks for the heads up. Seems it would be more reasonable to get a lighter pack for the bike itself, maybe a 48v 15ah lifepo4 battery which should still allow me to do a decent range and then invest in a bigger 48v 20ah battery in the future for those longer distances for use in the back of the trailer.

Finding a 48v 15ah battery that would sit neatly in the frame is definitely the hardest part. The latest prices i've got from a 48v 15ah battery were around $450-$500 I believe. Is there anyone in Australia that may be able to source out premade lifepo4 batteries in the specs/dimensions I was looking for?

 

[Kingfish]

My present Commuter pack is configured as 15S6P LiPo and that can take me about 50 miles/80 km if I take it easy on the throttle and the weather is good. To get that last 20 km though I’d have to bone up with panniers or drape the saddle bags to add another 15S2P. That’s cruising > 25 mph/40 kph. Batteries weight would be roughly 30.4 lbs./18.8 kg. If I had to make that as a commute each day it would push against my comfort level. However as a weekend day trip it would be an easy ride, terrain pending.

Pack a lunch, have fun!
~KF

 

[dogman dan]

Yes, that's often the catch 22. With typical pouch cell lifepo4 packs such as pingbattery sells, even a 48v 15 ah won't fit in all bikes triangles. But it will fit in many that have a more traditional, higher top bar frame. A 48v 20 would not fit in most bike triangles. Including some kind of box, you need about 6 inches by 13 inches of space, to orient the pack in the frame so it's as narrow as possible. Then you have about 4.5 to 5 inches of width which is easy to pedal around. You can fit tighter hole if you orient the pack the other way, and have a 6 inch wide box.

I highly recomend that you pony up the money for a 48v 15 ah or 36v 20 ah lifepo4 pack, if your motor will use a 20-25 amp controller. You'll love the difference from lead, the lightness is nice, and being able to dicharge 100% without actually damaging the battery horribly is very nice, but what's really nice is having decent speed the entire ride. With the lead, you like the bike wheeling out of the gararge a lot, but then 2 miles later it's just not the same bike as the voltage drops and drops and drops.

It IS a lot of money, but compared to the cost per mile of driving cars, you just can't spend your money much better than on some lithium for the ebike. The $500 or more for a good lifepo4 pack seems really expensive, but if you do the math it's pennies per mile vs driving cars at fifty cents USD or more per mile. I got 7000 miles from my first pingbattery. Every day I rode to work a 30 mile round trip put 12 bucks in my pocket to spend on more ebikes.

 

[whatever]

I ride 10km regularly, takes about 3.5ahr, some hills and very little pedalling ( 48v system) . Lithium cobalt pack.
So on that basis 100km would require 35ahr.
My longest ride was 60km I took two packs with me and changed over part way through the ride, one pack was 10ahr the other one was 15ahr, some decent hills involved in that ride, so some pedal assist on hills and just motor power alone on flatter sections.
100km is achievable but bike will be heavy due to the battery weight, wouldn't be practical to use sealed lead acid batteries they would be way way way to heavy.
I think that two packs of a123 20ah 48v would do the job, but its going to be alot of weight on the bike.

 

[arkmundi]

Yea, reading all the above and thinking about it as I have, 40ah of LiFePO4 would do it for ya' buddy. I'd go for the A123 AMP20 pack build as I and others have described it. But Ping would work, or Cellman or Headway. I'd be interested in the followup, as in how many miles you were able to clock after redoing the power pack.

 

[chopper_elec]

I love this forum thanks so much. I get so excited when there is a new reply notification yay

I'm thinking about running the following:

48V 15-20ah Battery

I've been getting around 30km out of my SLA 12ah batteries. Not sure if I may be pushing them too much but they are only temporary for another month or two.

I do take off nice and slow with the use of pedal assist (even though the single speed gearing isn't great for take off and my legs can't turn fast enough to do more than 39km an hour).

The ride that I love doing is around 60-70km there and back so I think I might aim for that.

I would love to try the trailer idea one day, another 15kg weight in the back of it would give me an extra 30km I thought I got funny looks now, just wait for the trailer haha

It seems with my riding patterns I should be able to get 40-60km out of the 15-20ah battery I reckon.

 

[liveforphysics]

I carry 50Ah at 28s (about 5kWh) on deathbike, with the option of removing the rear module easily which leaves it at 25Ah of 28s.

That's equal to ~5 of the 48v 20Ah ping packs. Riding at low speeds >100miles would be possible, but I generally can drain it in 50-80miles of my normal pace (45-85mph).

 

[Willow]

.......... I generally can drain it in 50-80miles of my normal pace (45-85mph).

your a madman.

 

[whatever]

can anyone explain the relationship between a batteries volts and ahr ( capacity) and how they are converted to kwh??
for eg. how many kwh would a 48v 20ahr a123 pack be? I've never understood kwh

 

[amberwolf]

W = A * V

 

[dogman dan]

So using that formula, the battery voltage, x amps = watts. So that would give you the watts of, for example a 20 amp controller. 48v x 20 amps, 860 watts possible if the controller is full throttle.

For watthours, it's simply amp hours in the same formula instead of amps. So a 48v 20 amp hour battery has the potential for 860 watthours. If you discharge it at one watt, it would run 860 hours. If you ran it at 100 w, it would run 8.6 hours.

The water analogy often helps visualize it. watthours or amp hours is like the amount of water in a bucket. Watts and amps are like how fast you can empty the bucket through a hole in it. 20 amp hole takes longer to empty than a 100 amp hole.