lifep04 from HK

[nechaus]

Have many of you used lifep04 from hobby king?
what are the cells like - cycle life? actual c rate? and anything else to mention..

 

[ElectricEd]

I recently bought some Zippy 30c LiFePO4 packs from HobbyKing. One had a cell that was about 1 volt below the rest, however doing a couple of cycles of discharges and recharges followed by a balancing, it came good. This was all done using a Turnigy Mega 400w V2 Charger, which is a really neat unit that shows what is going on for each group of cells in the series. It's been about 3 or 4 weeks now and it is still holding well.

On a different subject, if using Internet Explorer, once you register with Hobbyking, they have some sort of deal with Google that tracks your browsing. You'll start to get Hobbyking ads popping up on various sites that you go to. It really gave me the screaming willies as I reckon that it is an invasion of privacy and a bit too Orwellian. :x I HOPE THAT YOU SEE THIS HOBBYKING!


To get around this go to Tools|Manage add-ons|Tracking Protection. I have found the Abine tracking protection to work quite well.

 

[nechaus]

I still cant decide what lifep04 cells to buy

could go with the HK lifep04 (apparently 20c)
test out the a123 pouch cells... bit risky
or go with some high performance headways ( not the regular blue ones)

budget is around 1k to 1.5k for as many watts as i can get..

not gonna risk using my lipos on my commuter... nothing more embarrassing than a a small lipo fire or smoke at work or anywhere
I will most likely be charging @ work as my commute is going to be about 25km each way.. and some big ass hills

 

[bane77087]

I was just looking at those again myself. 30c out of lifepo4 sounds pretty good. But as usual no disclosed cycle figures from hobbyking. The live chat with a representative wasn't the right place to ask.

You are now chatting with : Cheryl (Customer Service)
Cheryl: Thank you for contacting the HobbyKing Support Team. How may I help you?
You: hello
You: I am curious about the cycle ratings on ZIPPY Flightmax 8400mAh 3S2P 30C LiFePo4 Pack
Cheryl: Unfortunately that we customer service representative are not trained with the technical aspects, if you require further assistance or recommendation, kindly seek for advise email us at support@hobbyking.zendesk.com, our staff with RC experience will assist you there.
You: ok ty
Cheryl: You're welcome! Have a great day!

I'm going to send an email to that address asking about the cycle life

EDIT: I got a email response 5 days later

Andrea, Feb 24 13:37 (HKT):

Hi Chad ,

Thanks for contacting the HobbyKing Support Team.

Thanks for your email and sorry for late reply. Thanks for your interest. We are afraid we do not have this kind of date sheet you required at this moment, but I will submit a request to check with related department.

You will be contacted again if we have any updates. Thanks for your support.

Thanks for emailing support.
If you have any other questions, please let me know.
Regards.
Andrea
HobbyKing Support Team
Dont forget to follow us on Twitter and Facebook for discounts and promotions!
www.facebook.com/hobbykinglive
www.twitter.com/hobbykinglive

 

[ElectricEd]

You are pretty safe if the cells are LiFePO4. In these batteries the oxygen is tightly bound with other molecules. In lithium polymer, the oxygen is loosely bound which makes it easy for a run away thermal reaction to occur. Hence the problems that Apple and Dell had with their laptops a few years ago.
Lipo is slightly more energy dense than LiFePO4, hence its use by RC modelers that need to really push the boundaries of weight and performance. Because of the inherent safety of LiFePO4, it's probably a much better option if riding on the road.
Imagine the cost if you came off and the bike slid under an expensive car and the battery was punctured.

I have yet to confirm from experience, but LiFePO4 is supposed to last longer than Lipo by about 50%.
As with anything, you get what you pay for. Buying genuine A123 cells will ensure that you get top performance but they are expensive. With the cheaper packs like Ping, Zippy and Turnigy, you are taking a bit of a gamble, but you usually come out OK. From what I've seen with long term ebikers, they break up their older packs to pick out the best cells and squeeze a bit of extra life that way.

 

[neptronix]

Those lifepo4 packs are lithium polymer, due to their pouch format
The other non-lifepo4 stuff that hobbyking sells is lithium cobalt, in polymer form.

Just wanted to be a douche & clear that up.

As for the lifepo4, here is my opinion... as with any hobbyking product, read the reviews from users, and if there are none, assume the worst.
These appear to have a worse dud rate than the traditional li-co stuff. That is all i know.
But the failure mode is of course, not a pyrotechnics show.

 

[mistercrash]

I bought 4 for RC use once, then a couple months later I bought another two and a few weeks after another 2. The first 4 and the next two all puffed because of deep discharge to about 2.5V per cell. I had the LVC set at 2.7 but we brought the trucks back to us despite the LVC kicking in instead of walking to get it. So the cells might have gone down to 2.5V. They don't seem to like that despite the fact they're LiFePO4 and I was told that this chemistry is very tough and has no problems with deep discharge and very fast charge. The last two were just sitting at storage voltage for a month and puffed for no reason. I never bothered getting more HK LiFePO4 packs. Maybe others will have more luck if you pamper them and don't let them sit for too long.

 

[LegendLength]

Lipo is slightly more energy dense than LiFePO4, hence its use by RC modelers that need to really push the boundaries of weight and performance.

I don't want to sound like an ass but I've got to take some exception to this. LiPo is about 30% denser than LiFe and the cost is nearly exactly half for LiPo (per watt hour). For example here is a comparison for HobbyKing Zippys:

Zippy 30C LiFePo4
Capacity: 69.3 Wh
Weight: 0.642 kg
Price: 79.88 USD
Density: 107.94 Wh / kg
Price / Capacity: 1.15 USD / Wh

Zippy 30C LiPo
Capacity: 92.5 Wh
Weight: 0.650 kg
Price: 54.85 USD
Density: 142.30 Wh / kg
Price / Capacity: 0.59 USD / Wh

Relative Denisity (LiFe : LiPo): 1.32 (i.e. LiPo is 32% denser than LiFe)
Relative Price per Wh (Life : Lipo): 0.51 (i.e. LiPo is 50% cheaper than LiFe)

As usual use whichever chemistry tickles your fancy. LiPo clearly has strong advantages over LiFe (price, weight), and some strong disadvantages (safety, cycle life).

 

[ElectricEd]

LiPo is about 30% denser than LiFe and the cost is nearly exactly half for LiPo (per watt hour).

Interesting, I hadn't realised that the difference in energy density was that much these days. When I first was doing my research before getting into ebiking it was around 10% as reported by Wikipedia at the time.
As for price, I don't mind the crash as much as I hate the idea of a crash & burn so am happy to pay extra.
It was the experience with my laptop that really turned me off Lipos. I'm about to go to my third battery in 3 years. With Lipos, they degrade over time as there is a base degradation rate that cannot be reduced, you can only increase it depending on how roughly you treat them. With such a short life, the longer life of the LiFePO4s effectively removes the economic advantage that Lipos may appear to have.

 

[amberwolf]

Those lifepo4 packs are lithium polymer, due to their pouch format
The other non-lifepo4 stuff that hobbyking sells is lithium cobalt, in polymer form.

Um, it doesn't matter what physical format they're in, pouch or not, they'd still be lithium polymer (LiPo), just like pretty much all flavors of Lithium-chemistry rechargeable batteries that we use.

Just sayin'.

 

[neptronix]

Those lifepo4 packs are lithium polymer, due to their pouch format
The other non-lifepo4 stuff that hobbyking sells is lithium cobalt, in polymer form.

Um, it doesn't matter what physical format they're in, pouch or not, they'd still be lithium polymer (LiPo), just like pretty much all flavors of Lithium-chemistry rechargeable batteries that we use.

Just sayin'.

I think maybe you didn't understand what i was replying to, i was just clarifying that lipo is the physical format, li-co is the chemistry, thus a pouch cell, even if the chemistry is lifepo4, is lipo as well.

It is an important distinction to make.

 

[neptronix]

Interesting, I hadn't realised that the difference in energy density was that much these days. When I first was doing my research before getting into ebiking it was around 10% as reported by Wikipedia at the time.
As for price, I don't mind the crash as much as I hate the idea of a crash & burn so am happy to pay extra.
It was the experience with my laptop that really turned me off Lipos. I'm about to go to my third battery in 3 years. With Lipos, they degrade over time as there is a base degradation rate that cannot be reduced, you can only increase it depending on how roughly you treat them. With such a short life, the longer life of the LiFePO4s effectively removes the economic advantage that Lipos may appear to have.

What you're talking about depends entirely on the chemistry.

+ Your lifepo4 packs *are* in lipo format.

+ lifepo4 cells vary widely in their wHr/KG, from ~90wHr/KG ( 'power' headway cylindricals ) to ~130wHr/KG ( A123 20AH lipo pouch ). The hobbyking lifepo4 you've got is on the lower end of that spectrum.

+ Your laptop battery was obviously poorly designed for the application. Cells for laptops vary widely in their cycle life and calendar life.. going on 4 years here with my original Dell battery.. Girlfriend's macbook ( li-co, lipo pouch style ) battery is still running and that laptop is circa late 2008, and she beats the hell out of it too.

+ Lipos degrade according to however what chemistry they have will degrade, hobbyking li-co does degrade fairly quickly, but there are plenty of non-lifepo4 chemistries that will survive for 10 years; look at the 8 ( or is it 10? ) year battery warranty on the Nissan Leaf's Li-Mn lipo setup.. Another example is the Dow Kokam Lipo ( NMC chemistry i believe ), which is rated for a few thousand cycles, just like any lifepo4, and has an abnormally long calendar life as well.

There are also plenty of crap cells in cylindrical format out there, some just as explosive as hobbyking's pouch li-co.. there is also plenty of crap lifepo4 out there too.

So yeah, you can't paint batteries with a broad brush at all.

 

[nechaus]

You guys know what im talking about...
I use regular lipo for my non communter bikes..
But this new build has to be reliable and as least dangerous as possible.

 

[rojitor]

Hi nechaus, i have those: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10311 i like them, the first batch had bad reports because they tended to inflate as balloons, as a matter of fact i sent two bricks back to china, right now they do not inflate and have a good c rate 30c discharge 5c charge. If you really need a safe pack i recommend them, nevertheless i must say ping are cheaper and zippy are lighter. Your choice.

 

[LI-ghtcycle]

Sounds again like a "you get what you pay for" situation, if you want solid performance, you really can't beat the A123 packs in LiFeP04 that cell_man sells.

Custom shaped packs, with BMS, in either the large format 20C pouch cells, or M1 cylindrical cells start at about $400 depending on what you need.

Sure Hobby King can sell you stuff cheap, and you can get lucky like I did (none of my LiPo packs came with bad cells) but you can see plenty of people who have a pack or two with a damaged or ruined cell in even the higher end packs.

Also, I have discovered, if you under-stress the packs, you can get lower performance too, so it's really about how much performance you need out of a pack in the first place, and then what's going to work best for you really depends on a lot of factors.

Personally, if you want rock solid performance on a LiFeP04 pack that you can just use and not worry about it, you want A 123.

That being said, I have a "daily rider" using Turnigy Nano Tech packs that has never stranded me, even when I was dumb and didn't bring a charger with me on a long trip and used down to a total discharge of 80% (this is the maximum I ever discharge my packs for longevity) and had very little power to use, I still got home on a 40 mile trip in the winter cold with too little power left to comfortably climb the big hill in town, but the batteries never failed me.

I'm going back to A123 on my next pack just because I want that rock solid performance especially in the colder weather, and nothing seems to be able to top the A123 20AH Prismatics for that IMHO.

Nothing wrong at all with LiPo, but both chemistries have their good and bad qualities, depends on what you value most.

I still have dreams of building a 50+ MPH exhibition bike running 130C Turnigy Nano Techs some day, but for a year round commuter, A123 seems to be a no brainer to me. :wink:

 

[ElectricEd]

+ Your laptop battery was obviously poorly designed for the application. Cells for laptops vary widely in their cycle life and calendar life.. going on 4 years here with my original Dell battery.. Girlfriend's macbook ( li-co, lipo pouch style ) battery is still running and that laptop is circa late 2008, and she beats the hell out of it too.


So yeah, you can't paint batteries with a broad brush at all.

My laptop is a Toshiba Tecra, top of the line when I bought it. It must be that Toshiba put crappy cells into their laptops if what you say is the case. I had exactly the same experience with 2 models of Toshiba Satellites prior to that since 2000. The only batteries that I have found to last more than a few years are nickel metal hydride.

On another matter, "Nothing wrong at all with LiPo" well, we'll have to differ there. I have a particular aversion to burning.

 

[LegendLength]

On another matter, "Nothing wrong at all with LiPo" well, we'll have to differ there.

I think he also differed with the text immediately after that quote:

Nothing wrong at all with LiPo, but both chemistries have their good and bad qualities

 

[neptronix]

On another matter, "Nothing wrong at all with LiPo" well, we'll have to differ there. I have a particular aversion to burning.

Might want to throw away / sell those lithium polymer lifepo4 packs then and get yourself some nice, big, heavy headways.

 

[ElectricEd]

On another matter, "Nothing wrong at all with LiPo" well, we'll have to differ there. I have a particular aversion to burning.

Might want to throw away / sell those lithium polymer lifepo4 packs then and get yourself some nice, big, heavy headways.

lithium polymer lifepo4 packs ??
Sounds like you are describing a hybrid battery to me. Are you trying to confuse? I don't give a hoot about the container type, its the actual chemistry inside that matters.

I didn't buy the Zippy LiFePO4 packs for an ebike, just as battery packs for weigh scales that are used where I work. The staff there are able to destroy things usually in the most spectacular way so I'd be really risking it to give them Lipos.
As I mentioned earlier "As with anything, you get what you pay for. Buying genuine A123 cells will ensure that you get top performance but they are expensive."
The only trouble with the A123s is that they don't fit into the space that's available in the scales.

 

[neptronix]

You havent read a word of what i've been saying have you..
You continue to refer to lipo as lithium cobalt cells..
Your lifepo4 is in lithium polymer packs; they are lipo.

It is important to make the distinction.

 

[el_walto]

Everyone calls RC packs lipo, but the chemistry in the packs is generally LiCo. Aka, the dangerous stuff.

I've been really happy with my cell_man pack so far. I've also been pretty happy with my ping battery packs. Neither of them are super light, or super small.

 

[full-throttle]

You havent read a word of what i've been saying have you..
You continue to refer to lipo as lithium cobalt cells..
Your lifepo4 is in lithium polymer packs; they are lipo.

It is important to make the distinction.

Why don't you just refer to them as cylindrical and prismatic?

Much less confusing

 

[neptronix]

You havent read a word of what i've been saying have you..
You continue to refer to lipo as lithium cobalt cells..
Your lifepo4 is in lithium polymer packs; they are lipo.

It is important to make the distinction.

Why don't you just refer to them as cylindrical and prismatic?

Much less confusing

That would work just as well.

Only point i'm trying to get across here is that 'lipo' refers to the format, not the chemistry.

Is that not clear?

 

[ElectricEd]

You havent read a word of what i've been saying have you..
You continue to refer to lipo as lithium cobalt cells..
Your lifepo4 is in lithium polymer packs; they are lipo.

It is important to make the distinction.

It's because what you are saying does not make sense as I have always understood lithium cobalt cells to be called Lipo because when they are made part of the process is to wrap the extruded lithium with a polymer layer containing the other electrode. Look through the posts on ES. I think you'll find that whenever anyone is referring to Lipo they are talking about lithium cobalt. Whenever the are taking about lifepo4 they mean LiFePO4. You are the first person that I have seen to make that distinction.
Either that or I have been operating for the last 4 years under a misapprehension. Can anyone else confirm or deny that please?

 

[neptronix]

I'm not the first person to make the distinction. Liveforphysics is also trying to drill this point home as well.

You have indeed been mislead; it is an informal term for a type of battery that was mostly unique to one chemistry for quite a long time.

li-co comes in cylindrical and pouch format, and it's characteristics are 100% determined by the chemistry, not the format.

NMC is referred to as lithium polymer when the manufacturer doesn't want to state the chemistry, so they talk about the format of the cell. They could also say 'lithium ion', which is even more vague and applies to everything from lifepo4 to lico, etc.

Li-Mn is also referred to as lithium polymer when it is in the pouch form.

A simple google search turns this up..

https://www.google.com/search?sourceid=chrome&ie=UTF-8&q=dow+kokam+lithium+polymer

Here is dow kokam constantly referring to their batteries as lithium polymer, but they are not lico.

https://www.google.com/search?sourc....,cf.osb&fp=4bd463be09dc681c&biw=1018&bih=789

LG's lithium polymer batteries are not lico either.

Ping battery has this to say:

http://www.pingbattery.com/servlet/StoreFront

Another key benefit of our LiFePo4 technology is its flexibility, both in terms of battery application and cell design. It can be used in wound cylindrical, wound prismatic and polymer battery construction types and manufactured to fit smaller applications.

another article.. if you are not totally bored yet

http://www.mpoweruk.com/cell_construction.htm

p.s. i stand corrected about the prismatic cells, those are oddballs ( pictured above on the mpoweruk link ), funny enough they are sometimes referred to as pouches.. guess i learned something here too