Lithium Ferrous Nano Phosphate battery

[stevebills]

why are these not used on ebikes?

A123 patented its Nanophosphate lithium-ion battery technology three years ago. The technology was developed at the Massachusetts Institute of Technology and was first used in DeWalt and Black and Decker power tools.

 

[Cyclezee]

why are these not used on ebikes?

A123 patented its Nanophosphate lithium-ion battery technology three years ago. The technology was developed at the Massachusetts Institute of Technology and was first used in DeWalt and Black and Decker power tools.

Hi Steve,

eZee have one listed for the conversion kit. See page 3 http://www.ezeebike.com/eZee Conversion KIT.pdf .

 

[flecc]

That name is a bit cumbersome, better known by two other names which have appeared regularly in the forum.

The first is the chemical formula name: LiFePO4

The second is Lithium iron phosphate

e-bike manufacturers have been watching it's development for a few years but have hesitated to adopt until they can sure of production consistency in e-bike sizes.

The good news is that it potentially has a longer life than Li-polymer etc, though in practice the three years that seems possible on e-bikes is now being approached by Li-polymer in the best cases.

If large enough they can last very much longer, even ten years, but e-bikes are too limited in what they can carry to have big enough batteries for that.

And it should be remembered that e-bike battery usage is radically different from tool use, the latter much easier to satisfy.
.

 

[jbond]

There seem to be 3 approaches to LiFePo cells and battery packs
1. Ping (and others) pouches. Low C. Cheaper for high capacity. Best WHr to weight/volume ratio for LiFePo
2. Headway. Cylindrical cell. Medium C. 5,10,15,20 AHr per cell Now sold as packs with BMS by BMS Battery.
3. A123. Cylindrical cell. High C. Low capacity per cell (2.3AHr per cell). Only available from specialists like Cellman with BMS. Now turning up in all sorts of things like replacement M/C batteries for racing.

The trade off with LiFePo vs LiMn or the new composite LiNiCoMn is long life vs weight and price. The same AHr of battery is typically twice the weight and 50% more expensive. However they are also robust and seem easy to balance. The High C of A123 cells make them perhaps a better option than RC LiPo where high current is an issue. The low AHr per cell of A123 means you need an awful lot of them. eg 48v-10AHr is 64 cells

This makes me think that there's only two scenarios where A123 really make sense on E-Bikes.

1. DIY builds aiming for very high currents (more than 30A) as an alternative to RC Lipo
2. Very small packs for short scale commuting eg 36v-2.5Ahr or 5AHr. The High C rating means a 12s2p pack can support 25A which is at the high end of vaguely legal hub motor/controllers. A 12s1p (36v2.3AHr) is probably ok for the typical 250W legal set up.

If you expect to do a *lot* of miles, then perhaps the extra life of LiFePo makes sense. I had somebody suggest to me that the pace of change means that if you can get 3 years from the battery with moderate use, it's not really worth it since there'll be new options by then. Even in the year I've been following E-Bike tech, I've seen this happen.

 

[stevebills]

I think its about cost before battery and I dont no what the Nissan leafs battery type is but im sure there is better at a higher price.

 

[flecc]

I think its about cost before battery and I dont no what the Nissan leafs battery type is but im sure there is better at a higher price.

The Nissan Leaf's battery is an LiFePO4 type and the replacement battery costs just over £14,000. Four year warranty life.

Makes our £500 ones look cheap.
.

 

[stevebills]

The Nissan Leaf's battery is an LiFePO4 type and the replacement battery costs just over £14,000. Four year warranty life.

Makes our £500 ones look cheap.
.

£14000 is alot of petrol it equal £3500 a year

 

[flecc]

Indeed, e-cars are only for the wealthy at present.
.

 

[stevebills]

Hi Flecc
it says 8 year or 100k when I looked!
Shortly after Chevrolet announced that the Volt would come with a battery warranty of 8 years, 100,000 miles, Nissan followed suit saying also would offer 8/100 coverage themselves.

 

[stevebills]

The Nissan Leaf's battery is an LiFePO4 type and the replacement battery costs just over £14,000. Four year warranty life.

Makes our £500 ones look cheap.
.

Hi Flecc
it says 8 year or 100k when I looked!
Shortly after Chevrolet announced that the Volt would come with a battery warranty of 8 years, 100,000 miles, Nissan followed suit saying also would offer 8/100 coverage themselves.

 

[Cyclezee]

Hi Flecc
it says 8 year or 100k when I looked!
Shortly after Chevrolet announced that the Volt would come with a battery warranty of 8 years, 100,000 miles, Nissan followed suit saying also would offer 8/100 coverage themselves.

Sorry Steve, could you repeat that please

 

[stevebills]

Sorry Steve, could you repeat that please

Hi Flecc

It says 8 years/100k your wrong!

 

[flecc]

That's the marketing claim, and we all know about those with lithium batteries . The warranty is as I said.

The validity of four years is also being borne out by the rivals being launched around the same time by PSA (Peugeot, Citroen), who are only leasing for four year periods to cover one battery life at similar overall costs, it's not possible to buy them.
.