Update on LifeP04 batteries

[Kudoscycles]

I have had my a123 packs for around 2 and half years now and keep them fully charged. Lets say I cycle them on average around 4 times a week (some times more sometimes less) which would equals over 500 cycles. My recent battery tests gave an average of 2.04 ah and the initial back tests in 2006 gave 2.12 ah average, so I lost around 5% so far. If I can keep this up I should be able to reach 2000 cycles in another 6 years and will be just reaching the 80% mark by that time. So far they are my longest lasting EV component...heck my longest last EV thing all together.
This has been lifted from the ES forum.


I still would love to use LifeP04 (Lithium Iron Phosphate)on every bike....we have 700 LifeP04 batteries out in use that are now coming up 2 years old,the only failures are in the BMS,we have never replaced a battery because of the cells ageing.
I have noticed that the back up batteries used in these PV solar farms are mainly using LifePo4 as opposed to SLA,despite the higher initial costs,principally because of low maintenance and long life-6 years is the budgeted life.
Lifep04 was originally developed for remote weather station usage,some of the original batteries are still in use 16 years later.
It is cheap,the safest of all the Lithium family,it is not temperature sensitive(ok -20 to +50)...its only negative is its relatively low energy density(its heavier),about 2 kg on a 10Ah battery.
And yet the Lifep04 gets ignored just to save a bit of weight-its you guys who want bikes to be lighter that has caused me to select LiMn04 on our new performance bikes,I cannot get a bike down to around 20kg and use Lifep04....be honest how many of us could usefully save 2kg off our bodies!
KudosDave

 

[jazper53]

Maybe we could create a diet sheet to save our Lifepo4 batteries. Will replacement batteries still be Lifep04?

 

[Kudoscycles]

Maybe we could create a diet sheet to save our Lifepo4 batteries. Will repacement batteries still be lifep04?

Jazper,all replacement batteries will be same as OEM bike....if it had LifeP04 on as standard,it will have LifeP04 as replacement.
KudosDave

 

[jazper53]

Jazper,all replacement batteries will be same as OEM bike....if it had LifeP04 on as standard,it will have LifeP04 as replacement.
KudosDave

Glad to hear it, as my Lifep04 battery has functioned very well, and never lagged in power even on the longer runs

 

[flecc]

....be honest how many of us could usefully save 2kg off our bodies!
KudosDave

At under 64 kilos this morning, not me! I want motorists to still be able to see me!

On the LiFePO4 life, it's important to also consider the number of charges they are capable of, especially for a daily commuter charging every day. Our longest experience of high quality examples of these is of those supplied by Li Ping to members. They seem to correspond to Ping's charge indications, 1000 charges definite, up to 2000 charges in light drain applications on the lower powered e-bikes, both to about one third loss of capacity. And any lithium based cell loses some capacity with age at typical operating temperatures, regardless of it's chemistry

So on the average moderately powerful e-bike, 4 years is likely, but the mentioned lives of 6 to 16 years are not possible for regular e-biking.

Any battery type lasts a very long time with the most gentle use and avoidance of the charging/discharging of the capacity extremes. NiMh and early lithium-ion batteries easily lasted 10 years in satellites for example, simply by providing very much more capacity than was needed. For the weight and bulk reasons mentioned, that is not an option for e-biking, making e-biking one of the toughest of all battery applications.
.

 

[oigoi]

All we need now is for them to be recyclable instead of going into a hole in the ground. There's only so much lithium in the world we need to think about truly sustainable technologies

 

[baldylox]

LifePO4 not an option on the new Arriba/Ibex then? And all down to keeping the weight down or are there other reasons for this also?

 

[flecc]

All we need now is for them to be recyclable instead of going into a hole in the ground. There's only so much lithium in the world we need to think about truly sustainable technologies

There is one existing lithium recycling system, but not in Britain and not very successful. Not only is it an expensive process, it can only recover about 50% of the lithium content at most. The fact that it exists at all is probably due to the need that politicians hope will arise from large scale sales of e-cars, a vain hope I fear.

 

[jackhandy]

LifePO4 not an option on the new Arriba/Ibex then? And all down to keeping the weight down or are there other reasons for this also?

I don't think they would fizzickly fit in the bottle-type can, would they Dave?

Maybe something suitable in a couple of years, though; who knows?

 

[Zebb]

Dave

Would it not be possible to split a 36v LifeP04 pack in two, so the 2 packs are joined with a cable so that.one pack could sit on one part of the frame (water bottle position )the cable follows the frame, by the crank and the other side of the pack sits on the upright of the frame, so the bike is not so top heavy.

Thanks.

 

[muckymits]

The main reason for them being heavier is they are a lower voltage so requires more cells for a pack, would it not be better to run a lower voltage system. Yes I know its means less watthours but there must be some fiddle here?

 

[Kudoscycles]

LifePO4 not an option on the new Arriba/Ibex then? And all down to keeping the weight down or are there other reasons for this also?

Baldylox...the speccing of these ebikes is always a compromise. I spent some efforts with several battery suppliers to get LifePo4 on the new performance bikes but the space in the triangle and wanting to use an off the shelf battery canister would have only allowed 6-7 Ah capacity. I think that is too low a range.
It was feedback off this forum(Eddieo mainly) that said that the best location for both looks and bike balance was the battery on the downtube,add in the extra 2 kg weight and the logical choice was to go away from LifePo4-others have complimented favourably on the appearance and lightweight of these new bikes.
However,conscious that the life expectancy would be lower I was determined that the price should be kept low for replacements (£198.00). I must say that £400-£600 replacement battery costs on Bosch powered bikes,batteries that may last only 2-3 years, doesn't seem to put others buying the likes of KTM,Haibike,AVE,Kalkhoff bikes,so maybe my attempt to extend the life of batteries and keep battery replacement costs low is not of much concern,I am surprised in these tough times.
KudosDave

 

[Zebb]

ok I will try again.
Dave kudos

Is it not possible to have 2 smaller lifepo4 packs linked in the frame to create 36v. one where the
water bottle is, one on the up right. this would stop the top heavy, having them on a rack.
thank you.

 

[jackhandy]

I must say that £400-£600 replacement battery costs on Bosch powered bikes,batteries that may last only 2-3 years, doesn't seem to put others buying the likes of KTM,Haibike,AVE,Kalkhoff bikes,so maybe my attempt to extend the life of batteries and keep battery replacement costs low is not of much concern,I am surprised in these tough times.
KudosDave

I suspect there will be some gnashing & wailing of teeth in a couple of years' time, when those punters actually have to part with that sort of cash, though - Assuming Bosch still supply replacements by then.

 

[cwah]

Agree that these A123 are amazing and have consistently received positive review... even from recycled ones (the ones I purchased from Victpower)
Are you selling A123 too? Because if I remember it correctly, not all Lifepo4 were born equal. Lifepo4 from HobbyKing for example don't have the best reputation...

BmsBattery are now selling 720WH of NiCoMn at 5.5kg, so at 130wh/kg I can get quite a decent pack with BMS included for £200

Same capacity lifepo4 cost the double....


So, when I'm weighting the pro and cons, I'm heading toward NiCoMn I'll change every 2 years... As it's almost 2 times lighter and 2 times cheaper than Lifepo4.

 

[cwah]

Also, I like lifepo4 but they are temperature sensitive. If you charge them at 0C or lower, you'll experience permanent capacity loss. That was a quite annoying point for me with my A123 during winter.

 

[Kudoscycles]

ok I will try again.
Dave kudos

Is it not possible to have 2 smaller lifepo4 packs linked in the frame to create 36v. one where the
water bottle is, one on the up right. this would stop the top heavy, having them on a rack.
thank you.

Zebb,I need to get these new bikes into stock. Once that happens I will look into maybe an oval shape canister that will take say 12 Ah of LifePo4 or 16Ah of LiMno4.
KudosDave

 

[Kudoscycles]

Also, I like lifepo4 but they are temperature sensitive. If you charge them at 0C or lower, you'll experience permanent capacity loss. That was a quite annoying point for me with my A123 during winter.

Cwah.....never experienced that,are you sure that the BMS isn't playing up. The spec says good for minus 20...I am sure other Kudos LifePo4 users must have charged their LifePo4 in the recent cold weather....the cold seems to cause reduced range but that seems typical of all the Lithium batteries.
KudosDave

 

[flecc]

Some types of lithium batteries can operate well under zero degrees C, but they should never be charged at under zero degrees C and preferably charged at more normal temperatures for long life. That's probably why Cwah had his failure.

 

[Zebb]

Zebb,I need to get these new bikes into stock. Once that happens I will look into maybe an oval shape canister that will take say 12 Ah of LifePo4 or 16Ah of LiMno4.
KudosDave[/QUOTE

Thank you.