Ping LiFePO4 batteries vs Ebikes.ca nicad (72 v)

[Sid]

I'm looking to build a 72v 530X (not sure which one I want yet) and I'm not sure what battery I'd want. I'm torn between batteries and I was wondering if I could get some help. I ride about 20 miles every day and my ezip motor is just not cutting it for what I'd like it to do (but hey, at least I have the steel bike now!)

6 24v 8AH nicads from ebikes.ca, because of the 5c rate (I want to throw as many amps at it as I safely can) and because I could evenly distribute the weight. Unfortunatly, I'm not sure on the life of these because ebikes.ca only says "when treated right they have been known to last for many years" and I'm not entirely sure of what they mean when treated right (Special charger, or just a regular nicd/nimh charger? Low amp draw?) Unfortunatly this configuration would require me to wire some of them in parallel, which I've read is bad for NiCads, but charging them seperately is possible if it were to dramatically extend their lives.

Edit: Then again, the longest I'd ride without charging would be ten miles or so (with stoplights and hills to be accounted for), would 8ah of nicad get me that at 72 v?


2 36v 15 ah LiFePO4's from ping because It's significantly smaller (I might even be able to make them work with the battery rack on the ezip), and because ping gives an actual life cycle, but I'm not sure if the 2 c rate is enough for what I would want.

For a bike like I'm trying to build (electric motorcycle that I can pedal home if need be) which would you suggest? Bear in mind, I live in kansas, so I have about only major hill on my commute. Also, weight isn't an issue, as I only weigh 140 and the bicycle is totally steel and unsuspended.

 

[patrickza]

Are you sure you want to go without suspension on a high speed bike?

 

[Ypedal]

For 20 miles, how about 10ah worth of Headway or PSI cells ! :wink:

 

[Sid]

The rodes I take run through the upper-class areas of town, so they are all very well taken care of, so I don't think it will be an issue. I may consider big apple tires, But considering the weight of the kit I'd like, I definitely want a bike to support it.

 

[dnmun]

without knowing the motor and controller, it is not possible to evaluate. have you looked at other projects and have an idea of whether it is gonna be motorcycle or a bike? will you need to put it on the bus bike rack or ever need to pick it up and carry it up stairs? how fast and how much weight will you pull in a trailer?

 

[Sid]

without knowing the motor and controller, it is not possible to evaluate.

It's gonna be a x5303 most likely, with a 72v 35 amp controller

have you looked at other projects and have an idea of whether it is gonna be motorcycle or a bike?

It's gonna be a bicycle frame

will you need to put it on the bus bike rack or ever need to pick it up and carry it up stairs?

Nope, bicycles in wichita are almost unheard of. A bike rack on a bus would make most people here go into an seizure.

how fast and how much weight will you pull in a trailer?

I'm not planning on having a trailer at all. I'll have my backpack on most days with my laptop, but that's it. I may pull a kiddy trailer, but that will be ~1 mile round trip to the nearest kroger.

 

[kriskros]

bike and me about 190lbs.... 36v,12amp ping v2,infineon 36v20amp and CA...bafang motor[slow wind....factory error]...with some pedaling have gone 42 miles.... slight rolling terrain.. average speed about 15mph if thats any help

 

[gerhardt]

Hi Sid,
Have you considered the two speed 400 series hub motor instead of the 500 series? I use the two speed 400 series with a 72V-35A controller. My top speed is 35 mph. My Safety E-Trike weighs 100 lbs. and I weigh 200 lbs. The trike is designed to carry an additional 100 lbs of cargo. My max current is 38 amps at 72 volts. The 72V-20A controller fails on hills. The 400 series hub motor will save you weight and money. Does any one have any experience on the maximum current possible with the Crystalyte 400 series hub motor? I attached a photo of the Safety E-Trike.

 

[Sid]

No experience on max current x5's, but some experience with crotch rockets, which I'm guessing is somewhat transferable. I plan to have a cruising speed of about ~30 mph, but having a higher max speed than I intend to go is always nice, which is why I'd like an x5.

 

[pwbset]

The 72V-20A controller fails on hills.

Not if you add some solder to the shunt!

Does any one have any experience on the maximum current possible with the Crystalyte 400 series hub motor?

All last summer I dumped 2kw+ sustained into a 4011 for 15min straight each morning climbing 1,600ft vertical over 3.5mi. They can take a ton of abuse.

 

[gerhardt]

Hi pwbset,
Thanks for you reply. I assume you are operationg your 400 series hub motor at 72 volts. Over 2kw means that your were using at least 28 amps with the 20 amp controller. I would also see a peak of 28 amps with the 20 amp controller. A capacitor exploded in my 20 amp Crystalyte controller. I will probably stay with the 35 amp controller since I want a problem free design for 50,000 miles and 10 years life.

Thats great news about the durability of the 400 series hub motor. Once I find it's limits I will probably program a controller to limit the amp draw based on temperature and power consumed for the past 5 minutes. I am also interested in upgrades to the 400 series hub motor to lower weight, better magnets, better bearings, higher temperature wire, higher torque for hill climbing and higher efficiency. There is a possibility that I may go from 72 volts to 108 volts to give more torque at lower speeds. I am currently using a 404/408 two speed hub motor in a 20 inch front wheel. I use a Redline BMX steel fork with dual torque arms.

Don Gerhardt