Lifepo4

[aaannndddyyy]

Hi see there are Li Iron Phosphate (lifepo4) 36volt 10amp batteries on EBay for around 250 pounds with charger plus delivery, eBay UK Shop - PingBattery: 36V LiFePO4 Batteries, 48V 24V Battery, Electric Bike Scooter that’s in the same price bracket as NiMh and li-ion manganese . lithium iron phosphate (LiFePO4) batteries, or nano lithium-ion batteries as they are sometimes called, are the newest generation of rechargeable batteries on the market.
There are three types of lithium ion cells based on different cathode materials. They are lithium cobalt oxide, lithium manganese oxide and lithium iron phosphate types. Although lithium cobalt oxide cell has the advantage of high energy density, it suffers from safety concerns. Lithium manganese oxide cell has been evaluated for the application on high rate due to the better safety characteristics. However, its high temperature performance is the major drawback and experience from a lot of members on this forum a short life cycle. While Lithium iron phosphate cell has the best safety characteristics, long cycle life (up to 2000 cycles). It is very suitable for high discharge rate occasions such as EV.

[flecc]

I'm still a bit nervous about LiFePO4 though, since the bike manufacturers seem very slow in introducing them.

eZee have been trying them out for well over a year now, but still nothing arriving as yet, nor from any other major manufacturer, so I deduce that something isn't quite right yet, since the advantages are overwhelming otherwise as you've said aaannndddyyy.

Only the small Sunrunner outfit has them on bikes so far in the UK, and then only in a tiny size with a low powered motor.
.

[HarryB]

Originally Posted by flecc

eZee have been trying them out for well over a year now, but still nothing arriving as yet, nor from any other major manufacturer, so I deduce that something isn't quite right yet, since the advantages are overwhelming otherwise as you've said aaannndddyyy.

.

Do you think it is to do with finding a supplier or even that they have stocks of the LiMn-ion batteries (or tied into a contract to buy them)? Could be a number of things I suppose. I notice doing a websearch on LiFePO4 comes up with a number of suppliers for batteries specifically for ebikes (from the USA) and six months ago there were none. Perhaps they are just taking off. I suppose there are those like me who need a new battery now and are fed up with the LiMn batteries but don't want to go out and buy a NiMH only to find that technology moves on in a few months. Sorry maybe this thread shouldn't be in the FAQ section as it seems a good topic for general discussion.

[aaannndddyyy]

Hi HarryB. I dont have any problem if you want to quote my post and start a new one in another section of the forum.

[Ian]

It's rather square shape would not fit the Ezee battery case whose internal width is 64mm. And I guess Its smallest dimension of 95mm would be too wide for virtually all behind the seat tube mounts. A pity as otherwise it would be worth a gamble.

Also don't forget import duty and VAT will have to be paid by the purchaser, and I think as the only shipping service offered is UPS expediated there will be no escaping these costs, the consignee being invoiced by UPS before delivery.

[HarryB]

Ian,

They do a version that is 350x85x65mm so I suppose it is not impossible to get one to fit. You are right though the import duty and VAT make it questionable adding about £52 I think.

[Ian]

Originally Posted by HarryB

They do a version that is 350x85x65mm so I suppose it is not impossible to get one to fit. You are right though the import duty and VAT make it questionable adding about £52 I think.

Harry, by a strange coincidence (Or design?) that is almost the exact size required for the Ezee case, and possibly others too. Perhaps if these batteries begin to catch on competition will force prices down. I would be very interested to learn how they perform in the real world.

[aaannndddyyy]

All though this item has finished it dose give a picture of the battery with the dimensions Ian mentioned that will probably fit in the ezee case EBay no 270159880567
type; LiFePO4 E-bike pack
Volt; 36V
Capacity: 10Ah
Dimension: 350x85x65mm(Small in Size)
Weight: 6KG
This LifePO4 unit including the LiFePO4 pack, BMS(battery management system) and a 3A charger.

[IMG][/IMG]

[coops]

I may be wrong, but I get the impression (from some posts on endless-sphere) that, although the A123 'nano-phosphate' and other iron phosphate (LiFePO4) types share a similar name & iron cathode chemistry, there are structural differences between them which might result in differing performance (e.g. current supply or 'C' rating) & lifetime: maybe this partly explains the inconclusive trials?

The A123's are not commercially available, as far as I know, except by dissecting powertools etc. batteries.

At 6kg (does that include charger too, perhaps?) the 36V 10Ah LiFePO4 battery weighs more than a 9Ah NiMH? Higher cost, weight & uncertain performance and
lifetime would make it a non-starter for me. A single, taller and higher capacity battery to fit Ezee bikes would be good, but thats a tall order I guess .

Stuart.

[flecc]

I suspect that it is price that's holding back their introduction, they are expensive,

It's certainly not existing Li-ion stocks, since these are made just to match demand due to their self ageing characteristics, hence them intermittently not being available.

If there's no progress in us getting these for our bikes by the Spring, I'll happily buy one of these inserts and try it, but i won't bother in winter cycling conditions. Masochism isn't one of my strong points!
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