future e-bikes

[jbond]

but without exception battery manufacturers are saying the best batteries for electric bikes for the foreseeable future are exactly what is being used at the moment Lithium Polymer Manganese.

Just trying to understand what batteries are commonly used currently. ISTM we have :-
1) LiMnO4 rectangular cells as seen in typical Phylion rack mount cases
2) LiMnO4, polymer electrolyte, as supplied by Whisper and others
3) Ping LiFePo, shrinkwrapped soft pouches
4) A123 LiFePo, cylindrical cells
5) Headway LiFePo large capacity cylindrical cells
6) Thundersky LiFePo large capacity rectangular cells
7) RC LI polymer from Turnigy and others

Things I'm not sure about.
- The difference between 1) and 2). Are they both polymer?
- The chemistry of the typical RC LiPoly 7). Are they LiMn or LiCo? All the scare stories about fires suggest they're LiCo but I'm somewhat amazed this is still used. Given that almost all other industries have rejected it.

 

[tillson]

Your 14ah batteries are existing tech how are prices falling,they have gone up from £515 to £540 at one of your dealers, since i last looked a few months ago.

These batteries contain desiccated Panda. As Pandas become fewer in number, this essential ebike battery ingredient becomes ever more expensive. This in turn, forces, retailers to increase the price of their batteries.

It was the research into Li-ion batteries during the early 1950s by Cambodian midgets that lead to the decline in the Panda population. They were using way too much Panda in their battery chemistry.

 

[funkylyn]

PANDA ???????
WHAT IS PANDA ???????

.......oops.....or are you joking ..............you naughty man you

 

[fishingpaul]

These batteries contain desiccated Panda. As Pandas become fewer in number, this essential ebike battery ingredient becomes ever more expensive. This in turn, forces, retailers to increase the price of their batteries.

It was the research into Li-ion batteries during the early 1950s by Cambodian midgets that lead to the decline in the Panda population. They were using way too much Panda in their battery chemistry.

My own theory was as the wispers get louder the prices tend to go up,i thought the shortage of female lions would be more important than the pandas population,guess any excuse will do though.

 

[flecc]

Things I'm not sure about.
- The difference between 1) and 2). Are they both polymer?
- The chemistry of the typical RC LiPoly 7). Are they LiMn or LiCo? All the scare stories about fires suggest their LiCo but I'm somewhat amazed this is still used. Given that almost all other industries have rejected it.

I think both polymer. Cobalt is back in use but only as a component of compound cathodes. Although said to be manganese based, I think it's likely the cathodes of the latest generation batteries made by Advanced for example and used by Wisper and eZee are compound cathodes. This is the sort of thing that can crop up in lithium polymer battery cathodes now:

nickel manganese cobalt complex oxide powder polymer

with even more complex ones appearing, chrome appearing in some as well.
.

 

[Wisper Bikes]

Your 14ah batteries are existing tech how are prices falling,they have gone up from £515 to £540 at one of your dealers, since i last looked a few months ago.

Hi Paul you of course are correct this was because of exchange rates relevant at at the time the price list was made up, however there will be an adjustment in the near future.

All the best

David

 

[Wisper Bikes]

I think both polymer. Cobalt is back in use but only as a component of compound cathodes. Although said to be manganese based, I think it's likely the cathodes of the latest generation batteries made by Advanced for example and used by Wisper and eZee are compound cathodes. This is the sort of thing that can crop up in lithium polymer battery cathodes now:

nickel manganese cobalt complex oxide powder polymer

with even more complex ones appearing, chrome appearing in some as well.
.

As always spot on Flecc, thanks for your input!

It is so very tempting for manufacturers (us included) to run the batteries down as far as possible without damaging the cells so we can extend the range of our bikes. However now we have been able to safely increase the Ah available from our batteries we have decided to reduce the amount they can be discharged by, by 1V which will extend their working lives quite significantly without loosing range and keeping that "just charged" power for longer.

All the best

David

 

[Wisper Bikes]

These batteries contain desiccated Panda. As Pandas become fewer in number, this essential ebike battery ingredient becomes ever more expensive. This in turn, forces, retailers to increase the price of their batteries.

It was the research into Li-ion batteries during the early 1950s by Cambodian midgets that lead to the decline in the Panda population. They were using way too much Panda in their battery chemistry.

Absolute garbage Paul!

We stopped using both Pandas and Cambodian midgets in our batteries nearly 3 weeks ago now, we find Black Rhinos and Tigers have a higher energy density.

Regards

David

Apparently, the use of rare metals such as cobalt in battery manufacturer is not sustainable and is very expensive hence the current drive towards Sulphur, Carbon and even Oxygen to replace such materials. Although I must admit to having no idea how this works!

 

[jbond]

It is so very tempting for manufacturers (us included) to run the batteries down as far as possible without damaging the cells so we can extend the range of our bikes. However now we have been able to safely increase the Ah available from our batteries we have decided to reduce the amount they can be discharged by, by 1V which will extend their working lives quite significantly without loosing range and keeping that "just charged" power for longer.

Interesting. All the curves I've seen for Lion batteries show a pretty flat voltage against capacity used before a steep drop off just before capacity is all used up. Once you're into the drop off area, I wouldn't have thought a low voltage cut off of 32v instead of 31v (or 32.5/31.5 or whatever) is going to make much difference since the battery is already >95% discharged. But then the devil is in the details.

I've wondered if a switch from LiMn to LiFePo needs a change in controller LVC. The LiFePo (12 vs 10s) has a slightly higher normal voltage, but again once you're into the drop off region, I didn't think it mattered that the LiMn setting on the controller was now being used for the LiFePo.

 

[flecc]

All the curves I've seen for Lion batteries show a pretty flat voltage against capacity used before a steep drop off just before capacity is all used up.

I think those curves must be at quite moderate discharge rates. In practice I've found in e-bike use with powerful motors under working conditions that the voltage dips quite markedly as capacity falls. On present experience this seems to be more marked when a battery is in the second half of life, from about 150/200 charges onwards.
.

 

[Wisper Bikes]

We have been studying a new type of Li Mn cell currently used by the Chinese and US military. We have tested and rated these new cells in real e-bike test conditions at 1C discharge instead of the usual .2C discharge.

When tested at 2C and not .2C the difference in predicted life cycles in these and our existing batteries was significant, we considered that a raise of 1V from 29.5 to 31.5 was worth making.

The new batteries have a new way of connecting the cells, in each of the ten cell packs there are multiple layers, it is the way they are layered is giving so much better results. That is all they will tell us at the moment.

These batteries can handle a continuous 3C. At 1C they have a predicted cycle life of over 1000 with only a 20% drop. We believe these new cells will last at least twice as long as most normal Li Po cells rated to 500 cycles at .2C.

The other benefit of these new 15.5Ah batteries is they have tested at over 16.5Ah whereas in our experience most 15.5Ah cells in e-bike test conditions, give about 90%-95% capacity i.e. 14Ah.

We are still testing and will make a decision soon whether to install these new super Li Mn batteries in our 2012 bikes.

 

[funkylyn]

Hi David.....

Fingers crossed that they turn out to be as good as they sound.
Can you confirm that they would be interchangeable with current batteries on your previous bikes ?
Lynda

 

[Wisper Bikes]

Hi Lynda

I hope so too, I will keep the Forum up to date with progress.

To answer your question, although the battery shape will be different we have committed to keeping improvements and upgrades interchangeable with existing models wherever possible. With respect to batteries this will certainly be the case. When our stock of even the old side connection batteries has run out we will be replacing the cells with the latest available on the newest Wispers.

Best regards

David

 

[funkylyn]

Hi Lynda

I hope so too, I will keep the Forum up to date with progress.

To answer your question, although the battery shape will be different we have committed to keeping improvements and upgrades interchangeable with existing models wherever possible. With respect to batteries this will certainly be the case. When our stock of even the old side connection batteries has run out we will be replacing the cells with the latest available on the newest Wispers.

Best regards

David

You're a star

Just as a matter of interest......approx. how much are your car/boat chargers ?

cant wait to get back to UK and try your bikes

Lynda

 

[Wisper Bikes]

Hi Lynda, they are £86.81 inc VAT.

Looking forward to hearing about your trial.

All the best

David

 

[Scatty]

Hi Lynda, they are £86.81 inc VAT.

Would you not be able to use a normal invertor instead they start from as little as 25 quid

 

[funkylyn]

Hi Scatty......yes I could but dont you lose some power due to the extra distance between the 'objects' ?
I always understood that it was better to plug directly into the power source.
My idea, whilst motorhoming, is to use some sort of 'power pack' to be an extra power source whilst not on EHU.
However, if I decided on the kalkoff/raleigh then I would HAVE to use an invertor as I think wisper are the only make who do specific 12v chargers.