LiFePO4 batteries

you want packs or cells only ?
Hope you have the $$ to back up your request
P.S. 40C peak

What total voltage and capacity (amp hours) are you looking for?

John H.
Blue XM-2000
Ann Arbor, MI

Me too.

Would love a 48v 20 ah lifepo4. If anyone finds someone selling these, please let me know.

http://www.lifebatt.com/ ??

- David Herron, http://davidherron.com/

>> http://www.lifebatt.com/ ??

Kind of pricey.

John H.
Blue XM-2000
Ann Arbor, MI

Kind of pricey.

Funny you say that... I was thinking the same thing. :)

anybody know anything about this guy on ebay or have any comments on what he's selling? http://tinyurl.com/33dydw

US $449.99
new LiFePO4 Pack designed for 350W to 600W E-bike (36V 12AH)!! Newly Developed Powerful E-bike battery !!! Do not lose the Chance to get the Excellent pack!!! We also can make 48V pack.
Type; LiFePO4 E-bike pack
Volt; 36V
Capacity: 12Ah
Weight: 6KG
This LifePO4 unit including the LiFePO4 pack, BMS(battery management system) and a 3A charger.
Fit machine; 36v 350W to 600W E-bike/ scooter

anybody know anything about this guy on ebay or have any comments on what he's selling?

I wrote the last few people who purchased these packs. I also may have dropped the address of the forum into the message. :-) Here's what a couple of them wrote back:

I'm pretty sure I've come across that forum while doing some of my research for this project. I'm building a solar-powered recumbent trike. Using the E-4 mid-drive motor kit from ElectroPortal. Motor is rated 500W, 750W peak, 24V. I'm not unhappy with the battery pack so far. Managed to blow a 30A fuse my first time out, pushing the bike up a steep hill. Just got a Watt's Up meter and it's telling me that the battery dies after 8.4Ah (or about 200Wh) drawing at a rate of about 150-250 watts. It was advertised as 24V 10Ah. I would have expected to get less than 10Ah with an SLA but what I've read about LiFePO4 lead me to believe that I can expect something much closer to 10Ah.

it's seems to be a decent battery, It gives as advertised 10ah. I peeked a 49amp(watts up) draw albeit most likely only for a fraction of a second as I have a 30 amp breaker and it didn't pop.
I am using it with a goldenmotors 36volt 500watt motor. I've since ordered a 36v 12ah so I think they are a pretty decent battery

http://zeva.com.au/tech/LiFePO4.php

I got a follow up from the first ebay guy.

Update: I ran another test this time using a stationary bike trainer stand. Constant load at 300W and got 9.1 Ah (~230 Wh) out of the battery. Also found that my motor/controller is bleeding about .25 to .5 Ah of charge out of the battery every day that it's connected so that may explain the previous lower number.

"phet- excellent performance to price and expected to drop sharply by spring, will probably be first leading wide scale lith suppplier in the world"

But read this:

http://www.phet.com.tw/Products/pdf/LiFePO4%20Intro%20E1.9.pdf

Note their remark:

"Before using PHET batteries in any application, a approval must be issued by PHET."

And having also followed the continued unavailability of Valence's u-charge batteries as well, it appears that the is a mad rush to corner the market on these batteries and keep available solely to big manufacturers they make their deals with. The last thing they want is poor stiffs like some of us getting hold of these batteries and building our own EV's when there is so much money to be made from a bottom-to-top integrated global monopoly.

Isn't so-called "globalization" wonderful!

The .pdf document also seems to say that PHET not only claims exclusive rights to the manufacture and sale of the batteries that use their materials, but they have a legal claim as to where and how the batteries are used, if used in "electric bikes" "electric scooters", "powered wheelchairs" and "mobility scooters".

Am I mistaken about this?

PJD,
Am I mistaken about this?

I don't really understand how they can enforce it. What's the difference between them and the LiFEPO4 already being sold here?

Below are some initial observations recorded while using Yesa’s 12 amp/hour Lithium Iron Phosphate battery. Purchased directly from China, delivery time to USA was about a week.

The battery dimensions are approximately 6” x 8” x 4.5”.
Weight is under 6 Kg, or around 12 lbs.
Nominal voltage is 38.4, 3.2V x 12 cells in series.

Discharge statistics for Yesa 12 Amp/hour 38.4 volt LiFePO4 battery on an e-bike

Measurements were taken with the Cycleanalyst e-bike battery monitoring computer.
Motor was a Crystalyte 406 brushless hub motor on a 26 inch rear wheel, using a 35 amp controller,
Rider’s weight was 200 lbs.
Wind conditions were light.
The test was terminated after a 14.1 mile ride.
Measurements were taken every 3.5 miles.

Test was made on a new battery after one shallow (3 A/hr) initial cycle.

Resting voltage 36 hours after the first charge was 39.9 volts, or about 3.33V per cell.

After a 3.5 mile ride, mostly downhill, I consumed exactly 1 amp/hour, or 38 watt/hours.
The resting voltage after 10 minutes was 39.7.

After 7 miles, combined uphill and downhill riding I consumed 3.64 A/hr or 134 W/hrs. The resting voltage after 10 minutes was 39.5.
Minimum recorded voltage was 34.2, while maximum current was 38.2A, at 1300 Watts.

After 10.5 miles, combined uphill and downhill riding I consumed 5.1 A/hr or 189 W/hr. The resting voltage after 10 minutes was 39.4.
Minimum recorded voltage remained 34.2, while maximum current was 38.2A.

After 14.1 miles, combined uphill and downhill riding I consumed 7.86 A/hr, or 287 W/hr. The resting voltage after 10 minutes was 38.9.
Minimum recorded voltage was 32.5, while maximum recorded current remained 38.2A.

Total riding time was 43 minutes, at an average speed of 19.8 mph, and often traveling at up to 24 mph on level ground, without pedaling, and as high as 28 mph while assisting the Crystalyte 406 brushless hub motor.

The battery charger provided by Yesa put out the rated 3 amps, with a terminal voltage of 43.8. A built in relay fully disconnects the battery when the charge cycle is complete. The switch-mode type charger also has an integrated cooling fan, which does a fine job. Total charge time was just over 2.5 hours in this example. Total charge accepted was exactly 8 A/hr, or 326 W/hr.

Looking only at amp/hours, you might conclude that the charge efficiency was approximately 98%, (not including conversion losses in the charger itself). When observing watt/hours, a more accurate measure of 88% efficiency is observed, still very respectable.

Cliff K.
Montauk, NY