lithium cobalt battery v lifepo4

[stevebills]

I would be interested to know which is lightest and has more power to weight?
and which is best for an electric bike

 

[flecc]

Lithium batteries with cobalt cathodes were abandoned for e-bikes after numerous fires caused by their intrinsically dangerous properties. Batteries with manganese cathodes replaced them.

The cobalt batteries were more efficient and lighter, manganese no heavier but with lower current deliveries, LiFePO4 bulkier and tend to be a bit heavier for a given performance.

We now have batteries with compound cathodes based around manganese which include cobalt in a safe way, mostly li-polymer types.

So it's cobalt if you have fire insurance and don't mind risks.

Manganese or compound polymers for the best all round compromise.

LiFePO4 for the longest life.
.

 

[Oxygen Bicycles]

Lithium Cobalt have a higher power density, can defo get more Wh/kg than LiFePo4, the difference is the Li-Co is the most dangerous type which had a bad past full of explosions. LiFePO4 is on the other hand the safest one but weight more and can get less Wh/kg. LiFePo4 are most suitable for heavier vehicles (cars, mopeds) where weight isn't such an issue.

Tony (Flecc) will probably remember how many Wh/kg each type can achieve, I can't remember so don't want to post misleading figures.

The highest energy density per kg currently have the Li-sulphur cells, these are however still in the lab world and the lifecycle does not promise great results, not yet.

Currently lithium polymer (mix of Li,Mn, Co and few other) cells are the best for ebikes as they offer resonably light weight, good life cycle and safety which is crucial.

All the best

Andrew

 

[Oxygen Bicycles]

Whow, I see Flecc already posted while I was typing, thanks Tony

 

[stevebills]

The original reason I ask the question is because Optibike are going to be using them on there 3rd generation batteries.

In the fast paced, ever changing world of lithium-ion batteries and electric
bikes, one thing is certain: Optibike will continue to bring you the latest
and greatest in battery technology.

The 3rd Generation Lithium-Ion battery from Optibike is no exception.

· *Compact*. The Optibike lithium ion battery is the most energy
dense battery deployed in an electric vehicle today.

· *Durable.* Only Optibike offers a 3 year/30,000 mile warranty for
a lithium ion battery.

· *Powerful.* With 26ah at 36v, the Optibike Lithium Ion battery
system boasts the highest capacity primary battery available in an electric
bike today.

· *Lightweight.* 295% more capacity than the leading LiPO4 battery
of the same size and weight!

Hello Optibikers.

A brand new 26ah 36v battery with a new 3 year/30,000 mile warranty is
$2395. We are still offering the 22ah version for $1995 (with the
same 3 year/30,000 mile warranty)

The new battery is the same size and weight as the version 1 and 2
batteries, so they are compatible with any Li powered Optibike.

Just as a comparison, if we used A123 cells in lieu of Lithium Cobalt
cells, the battery would only have 8.8 ah rather than 26ah. This is
why Optibike uses Lithium Cobalt instead of LiPO4.

 

[NRG]

That extra years warranty sure costs though dosen't it!

 

[flecc]

· *Powerful.* With 26ah at 36v, the Optibike Lithium Ion battery
system boasts the highest capacity primary battery available in an electric
bike today.

This will be one of the latest compound cathodes including cobalt. Thse are getting increasingly complicated as this example shows:

Lithium-ion nickel manganese cobalt complex oxide powder polymer

and I see one research variant has now added chromium to that.

We have to be wary about high capacity claims though, capacity is not a fixed amount, it varies according to rate of current usage. For example, A to B Magazine carried out a series of test usages on a well known e-bike's li-polymer battery. Using the battery at the lowest practical rate of consumption showed it had the claimed 10 Ah capacity. Then with each increase in the rate of power used the capacity dropped, and at the highest rate, using maximum power continuously, it dropped to barely 7 Ah of usable content.

However, since 70% of this Optibike battery is still over 18 Ah, it remains as good as it gets on e-bikes with one battery.
.

 

[stevebills]

That extra years warranty sure costs though dosen't it!

yep it sure is pricey!

 

[tangent]

I am curious to know what is in the cheap RC "LIPO" batteries advertised on ebay and other places. These boast high C rates which I suspect means they are dangerous lithium cobalt. They seem exceptional value and would make great small capacity batteries if just strung together in series, but I am very suspicious of anything just called LIPO.

 

[Oxygen Bicycles]

I am curious to know what is in the cheap RC "LIPO" batteries advertised on ebay and other places. These boast high C rates which I suspect means they are dangerous lithium cobalt. They seem exceptional value and would make great small capacity batteries if just strung together in series, but I am very suspicious of anything just called LIPO.

I would say very risky business to deal with. I would advise anyone who wants to start building it own packs to actually read a proper literature before doing so. Obviously it's always best and most advisable to buy a ready built pack from a reputable company.

All the best

Andrew

 

[jbond]

Battery tech is becoming a serious minefield. And it's made worse by people and suppliers using fairly generic meaningless terms like LiPo or LiOn. They're all LiOn. virtually all of them now use a polymer electrolyte so are LiPo.

We've got:-
- 3 or 4 chemistries. LiCo, LiMn, LiFePo, LiNiCoMn
- In more or less 2 voltages per cell. Meaning that a 36v battery is sometimes 10 and sometimes 12 in series
- In 3 major packages. pouch, hardshell (Prismatic), cylindrical
- In several capacities per cell, from 2.3AHr to 20AHr
- With C ratings that vary from 1C to 30C
- Packaged with or without a BMS of varying max current
- In shrink wrap - duct tape or a hard case

If you're not just buying a manufacturer replacement, I think there are currently these options.

- Ping (or copy). Shrinkwrap pouch LiFePo. Low C (1C-2C). Typically 36v15AHr. Cheap, long lasting, heavy, bulky. Ping, VPower, eBay.

- A123, Headway. Shrinkwrap, Cylindrical cell, High C (5C-30C). Often custom made in anything from 12s2p to 16s4p A123, or 12s1p for Headway. Expensive, powerful, heavy, long lasting. The enthusiasts choice for high power setups or very small capacity, eg 36v2.3AHr. Cellman, BMSBattery, Codd

- LiNiCoMn rack mount case or shrinkwrap. Low C (1C-2C). Cheap, light, half the life of LiFePo (claimed 800 cycles vs 2000 cycles). This is probably the near term future as replacement for generic LiMn. The light weight/bulk of a 36v10Ahr battery for a legal e-bike is very attractive. BMSBattery (maybe), ECityPower

- RC Lipo. Cheap, light, powerful, limited life, dangerous. External BMS. Awkward charging. Good for very high power, very light weight for enthusiasts prepared to do lots of DIY and take lots of care. Turnigy, Hobbyking

 

[NRG]

Good summary JB but RC Lipo life is no worse now than LiFePo with the latest Zippy, Turnigy Etc batteries. and as with all batteries if you limit the LVC and HVC their life extends even further.

 

[EddieK]

lithium tech

Hi Guys,

I'm a fan of testing the various technologies on application.
Although they weigh more we have had better results on a Heinzmann 500w 33A sport using LifePo4 10Ah than using LiCoMn 10Ah.

The Triple Oxide cobalt Sanyo batteries (Ultramotor Metro) have performed well.

The cobalt (& cobalt compound) cathode batteries appear to be performance restricted by a capped LVC and HVC. The extra energy is there but the cells need to be used comfortably within their capacities to achieve their life cycle.

We have found it easier to source LiCoMn batteries with consistent qualities then LifePo which tend me be more hit and miss.

 

[jbond]

Good summary JB but RC Lipo life is no worse now than LiFePo with the latest Zippy, Turnigy Etc batteries. and as with all batteries if you limit the LVC and HVC their life extends even further.

I don't know or have experience of RC Lipo. I don't think I've ever seen claims of cycle life for them. My comments on life are from reading ES and seeing people complain about bad packs and packs going bad. Of course this is all further confused because Zippy and Turnigy now make LiFePo as well as LiCo batteries. You could put together a pair of HobbyKing Online R/C Hobby Store : Turnigy 4500mAh 6S2P 30C LiFePo4 Pack
and have 12s2p, 36v4.5AHr as an A123 30c (claimed) battery but with no BMS. That's going to be the same end performance and life time as other A123 based packs.

 

[pedro magrela]

Battery tech is becoming a serious minefield. And it's made worse by people and suppliers using fairly generic meaningless terms like LiPo or LiOn. They're all LiOn. virtually all of them now use a polymer electrolyte so are LiPo.

We've got:-
- 3 or 4 chemistries. LiCo, LiMn, LiFePo, LiNiCoMn
- In more or less 2 voltages per cell. Meaning that a 36v battery is sometimes 10 and sometimes 12 in series
- In 3 major packages. pouch, hardshell (Prismatic), cylindrical
- In several capacities per cell, from 2.3AHr to 20AHr
- With C ratings that vary from 1C to 30C
- Packaged with or without a BMS of varying max current
- In shrink wrap - duct tape or a hard case

If you're not just buying a manufacturer replacement, I think there are currently these options.

- Ping (or copy). Shrinkwrap pouch LiFePo. Low C (1C-2C). Typically 36v15AHr. Cheap, long lasting, heavy, bulky. Ping, VPower, eBay.

- A123, Headway. Shrinkwrap, Cylindrical cell, High C (5C-30C). Often custom made in anything from 12s2p to 16s4p A123, or 12s1p for Headway. Expensive, powerful, heavy, long lasting. The enthusiasts choice for high power setups or very small capacity, eg 36v2.3AHr. Cellman, BMSBattery, Codd

- LiNiCoMn rack mount case or shrinkwrap. Low C (1C-2C). Cheap, light, half the life of LiFePo (claimed 800 cycles vs 2000 cycles). This is probably the near term future as replacement for generic LiMn. The light weight/bulk of a 36v10Ahr battery for a legal e-bike is very attractive. BMSBattery (maybe), ECityPower

- RC Lipo. Cheap, light, powerful, limited life, dangerous. External BMS. Awkward charging. Good for very high power, very light weight for enthusiasts prepared to do lots of DIY and take lots of care. Turnigy, Hobbyking

this is one of the most useful comments on on of the most obscure subjects, even digging deeply in the internet, I really mean deep to the center of the netted globe, will not give a good perception. But your overview is now 3 years old. Could you update to the May 2014 situation of Lithium batteries on the market for e-bikes?

 

[cwah]

The original reason I ask the question is because Optibike are going to be using them on there 3rd generation batteries.

In the fast paced, ever changing world of lithium-ion batteries and electric
bikes, one thing is certain: Optibike will continue to bring you the latest
and greatest in battery technology.

The 3rd Generation Lithium-Ion battery from Optibike is no exception.

· *Compact*. The Optibike lithium ion battery is the most energy
dense battery deployed in an electric vehicle today.

· *Durable.* Only Optibike offers a 3 year/30,000 mile warranty for
a lithium ion battery.

· *Powerful.* With 26ah at 36v, the Optibike Lithium Ion battery
system boasts the highest capacity primary battery available in an electric
bike today.

· *Lightweight.* 295% more capacity than the leading LiPO4 battery
of the same size and weight!

Hello Optibikers.

A brand new 26ah 36v battery with a new 3 year/30,000 mile warranty is
$2395. We are still offering the 22ah version for $1995 (with the
same 3 year/30,000 mile warranty)

The new battery is the same size and weight as the version 1 and 2
batteries, so they are compatible with any Li powered Optibike.

Just as a comparison, if we used A123 cells in lieu of Lithium Cobalt
cells, the battery would only have 8.8 ah rather than 26ah. This is
why Optibike uses Lithium Cobalt instead of LiPO4.

It's just easy to say the most (place anything) and expect people to believe you lol.

Can you tell us what cell (brand and model) is it using? Currently the latest and best cells in the market are the Panasonic NCR18650 ranges. I don't know any better cell in the market but I'm keen to hear

 

[drsolly]

After doing some research, I decided on Hobbyking Lipo. For safety I use Lipo chargers. I don't know the battery life, but I'm paying £30 for 5AH, 8S (about 30 volts). So replacing 10AH of battery (£60) is going to cost me less than one tankful of petrol.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=26801