Li-ion or LiFePo

[Andy_82]

Hi all,

maybe a silly question but it's not straight forward to me. I'm looking for battery supplier and have heard of LiFePo batteries. Could anyone tell me in what sense it LiFePo battery better than the Li-ion. I heard that LiFePo's do more charging cycles but I was just wondering if there is any difference in the perfomance or weight? These are the questions I could not find the answers for?

One more, does anyone know a really good (reliable)battery supplier?

All comments very welcome,

[flecc]

LiFePO4 (lithium-iron-phosphate) batteries will easily last for 1000 charge cycles and under some loadings will reach up to 3000 cycles. They hold promise of 5000 cycles with further development and are being thought of as potential vehicle lifetime batteries. They are little affected by time. They are at present slightly larger for a given capacity that Li-ion manganese ones, and a little heavier than li-ion polymer.

Li-ion will only last for about 500 charges and many struggle to reach that without serious capacity loss. They also deteriorate with age, whether used or not, so about 2 to 3 years is as much as could be got, often less.

The reason LiFePO4 are not on all bikes at present is that reliable mass production has yet to be achieved at acceptable manufacturing prices.

However, there is one dedicated LiFePO4 supplier, Li Ping, who constructs batteries that members have found completely reliable, and two members have now had them for more than a year with no loss of performance. You will of course need the right charger which Ping also supplies. Here's his website where you can buy from:

Li Ping Store

I believe he also trades through ebay where the prices may be different.

Nobody has had the personal import of these caught by HMRC for duties or VAT, so the price you see is likely to be the total cost.
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[OneWayTraffic]

Just going to jump in here with the suggestion to go over to endless sphere and check the many many threads there about Ping packs. He offers good value, but you will be responsible for properly wiring and installing the pack on your bike, and it would be advisable to procure or fabricate a rigid case for it as well.

One more thing. You can be sure that as soon as the quantities come up, that there will be LiFePO4 available as an option on pretty much most bikes. Unless something better comes along, it's a matter of time is all. You could go Li ion now, and upgrade when it gives out.

[Andy_82]

Hi Flecc,

Many thanks for the comprehensive answer. This is now fully understandable. I just wonder when LiFePo will be affordable to the normal user. I hope it's a matter of one or max two years when we will all have the LiFoPos on our electric bikes.

Once again, thanks for the info

[flecc]

Originally Posted by Andy_82

I just wonder when LiFePo will be affordable to the normal user. I hope it's a matter of one or max two years when we will all have the LiFoPos on our electric bikes.

Difficult to say, but that's likely. There are other possibilities though. Before the current economic mess the industry was forecasting that Li-polymer batteries would substantially drop in price over the next couple of years.

If this eventually happens there are attractions for manufacturers to stick with them, since the replacements give a continuing income flow after the bike sale. It's the old "low price Hoover with bags versus expensive bagless Dyson" argument again, also seen in inkjets where the printers are dirt cheap but the ink is where they make the profits.

Time will tell.
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[Wooky]

Originally Posted by flecc

LiFePO4 (lithium-iron-phosphate) batteries will easily last for 1000 charge cycles and under some loadings will reach up to 3000 cycles. They hold promise of 5000 cycles with further development and are being thought of as potential vehicle lifetime batteries. They are little affected by time. They are at present slightly larger for a given capacity that Li-ion manganese ones, and a little heavier than li-ion polymer.

Are all Li-ion batteries manganese now? I notice Panasonic and Wisper make a point of mentioning it on their labeling whereas my Phylion doesn't (Neither does my Alien), nor on their website. I read somewhere that is was discovered adding Maganese to the positive electrode increased capacity.

Terry

[Bigbee]

I was looking at batteries again as I get confoosed!I read some where that flecc says Wisper use Nickel Manganese Cobalt,but on their site they refer to them as Li-Po?Is this the same?Also in theory are LiFePO4 batteries better than these?

[carpetbagger]

If i wanted one of these for a Powabyke is it just a case of putting it straight into the battery case and connecting the charger/controller or would some additional battery management be required ?

[flecc]

Originally Posted by Wooky

Are all Li-ion batteries manganese now? I notice Panasonic and Wisper make a point of mentioning it on their labeling whereas my Phylion doesn't (Neither does my Alien), nor on their website. I read somewhere that is was discovered adding Maganese to the positive electrode increased capacity.

Terry

Originally Posted by Bigbee

I was looking at batteries again as I get confoosed!I read some where that flecc says Wisper use Nickel Manganese Cobalt,but on their site they refer to them as Li-Po?Is this the same?Also in theory are LiFePO4 batteries better than these?

It's all very confusing due to the abbreviated way batteries are referred to by the suppliers, none of the references complete and accurate.

The Lithium refers to the basic material and ion to the electricity handling method, and these are all lithium-ion

Terms like cobalt, manganese etc refer to the cathode material used, while polymer refers to a type of cell construction that avoids rigid plates.

Therefore a battery can be lithium-ion manganese polymer, each word referring to something different and not contradictory. Of course mouthfuls like this are too cumbersome, so the battery and bike manufacturers use the minimal combination they think most attractive in sales terms. li-polymer generally the current favourite.

Now the background. Originally lithium ion battery cells used rigid plates with a cobalt cathode and these performed really well for current delivery, but with time it was realised that slight manufacturing faults could cause fires to occur, and you may have seen or read of the sudden laptop fires that occurred. These also affected many e-bikes and in at least one case someone's house was burnt down as a result. Clearly something had to be done rapidly about the cobalt cathode which was the source of the trouble although not the direct cause.

There's about a dozen elements which are suitable for this cathode use in ascending order of suitability, with cobalt fairly high up the range, but the only suitable alternative which could be used with the technical knowledge available at the time was manganese which was very safe. Unfortunately it was lower down the range of suitability and couldn't deliver current as well, and led the well known battery failures on the more powerful bikes,

With time the chemistry and construction was improved, making them mostly just about good enough, but clearly more was needed, so some complex cathodes were created, basically a compound blend of the former cobalt with manganese and additional elements which was both safe and better at delivering current, and these are the expensive top grade cells of today that you see in batteries used by Wisper, eZee, Panasonic, BionX etc.

The polymer construction came in parallel with the developments in chemistry, and it's basically a particulate way of constructing the contents that allows soft cell casings and almost any shape of cell to be constructed. The attraction for e-bikes is that these are very much lighter than the former plate cells with rigid cases, which were often made of welded steel.

So going back to the terminology, we can now have this sort of battery:

Lithium-ion nickel manganese cobalt complex oxide powder polymer

with even more complex ones appearing, so I bet you're now pleased the manufacturers do abbreviate!

The latest development of LiFePO4 has the name lithium iron phosphate, note the word "iron" not ion, though these are also ion batteries. Iron is right at the top of suitable cathode materials, but for years it proved very difficult to find a way of using it. That's now been cracked with iron phosphate. Because iron is so suitable these promise to eventually be lifetime batteries, and they will already accept between 1000 and 3000 charges depending on the rates of discharge, in turn depending on the power of the motor used.

As yet the mass production of acceptably priced versions of these for our continuous high discharge use on powerful e-bikes has not been reliable enough, though they are used successfully in more intermittent applications like power tools. They should arrive for us eventually.

For the future there's developments of the anode material in hand. At present they all use carbon anodes which perform well so have not had much attention, but these will be improved upon. And of course there's always the possibility of a completely new type of battery appearing, though none of the other current advanced types are suitable for e-bike use.
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[flecc]

Originally Posted by carpetbagger

If i wanted one of these for a Powabyke is it just a case of putting it straight into the battery case and connecting the charger/controller or would some additional battery management be required ?

With the traditional Powabyke, using their new lithium batteries is just a matter of swapping, but for the Ping LiFePO4 one, you'd have to check the dimensions and make sure you choose one that fitted in the box. The BMS and a new charger is included, but you would have to organise the wiring. Because the Powabyke motor is so powerful, best to choose a 12 Ah version.
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