Calb's 40ah cells ?

[mauimart]

I am currently running this exact setup. It might be a bit bulky for a foldable but on my generic mountain bike it's not too bad. I routinely do about 3c as I live on the slope of a significant mountain. The bike has plenty of power for the hills and I've had her up over 45mph on the flats. In general the large prismatic format is easy to deal with if you have the space. Fewer cells means fewer interconnections and simpler management.

Martin

 

[dogman dan]

Might want to add the same bms ping uses. And consider the cost of a charger along with the cost before you decide.

40 ah would give you one heck of a long range. Do you really need that much? I find packing a 15 pound ping gives me at least 25 miles of range.

If you really do need that much range, then go for it.

 

[Alan B]

8S 40AH is about equivalent to 16S 20AH total energy-wise. Lower voltage means higher current to get the same power. Heavier wires, physically larger and heavier motor, controller, etc. It is a tradeoff.

 

[mauimart]

I am currently running this exact setup. It might be a bit bulky for a foldable but on my generic mountain bike it's not too bad. I routinely do about 3c as I live on the slope of a significant mountain. The bike has plenty of power for the hills and I've had her up over 45mph on the flats. In general the large prismatic format is easy to deal with if you have the space. Fewer cells means fewer interconnections and simpler management.

Martin

Hi Martin,

Im glad you posted those pics as they give me far better idea and as it hilly here ( well more gradual slopes - not the alps )
this sounds like a good idea , do you get good range , what sort of kit is that your using ?

You got me thinking it might be a better idea to look for trike of some sort or recumbent , as it pretty obvious i coldnt really stick these in bag .

thanks,

che

che,

I have not formally tested the range yet. I don't think I've gone past 20Ah of discharge. My guess would be around 40 miles on flat terrain. As far as the components go the motor is a Scott PM 1hp and the controller is a Curtis 1204. These are components that were previously used on an Electrathon project. There are more specs on the bike at http://www.evalbum.com/948. Everything there is accurate except that I upgraded to the CALB cells from lead acid wheel chair batteries. The new curb weight is now about 85 lbs down from 105 lbs following the upgrade. Top speed, acceleration, and range have all improved with the LiFePO4 cells. I hope to get some better test numbers once my arduino based computer is done. It will have similar capabilities to a Cycle Analyst with the ability to log data to an SD card. I have attached some additional photos.

I do think these cells are better suited to larger EV's such as those that fall into the scooter, trike, and motorcycle categories; ones that do not rely on pedal assist. Although I do not have too many cycles on them (< 100 at ~50% SOC) they have and continue to perform quite well. My primary goal for this project was for it to be used as a test platform to help assess the performance of the CALB cells that I may later use on a larger scale vehicle: (https://sites.google.com/site/seaburyhallengineering/electric-car) or on my 1st gen Honda Insight.

Martin

 

[dogman dan]

Yes, that's true. 24v 40 ah is still not so huge. It gets a bit tricky to mount similar weight 48v 20 ah packs on a bike, but on a scooter it may be less of a problem. You will have some good range with a pack that size depending on the use, like steep hills. For sure you ought to see 30 miles on flattish ground.

For those of us carrying lifepo4 on a rear rack of a bike, 24v 30 ah, 36v 20 ah, and 48v 15 ah are the practical sizes to carry, (15 pounds) and give us 20-25 mile range. So I thought maybe you wouldn't need the extra expense and extra weight or 24v 40 ah.

 

[sangesf]

I use 2 - 36v 20ah LiFePo4's on a dual motor setup and get anywhere from 80 to 110+ miles depending on all the obvious variables.

So I would figure a 36v 40ah would do close to that on a single motor.