A123 vs. Turnigy (LiPo) vs. Zippy (LiFePo4) vs. you name it

hillyterrain

100 W
Joined
Feb 27, 2013
Messages
132
Location
Bay Area, CA
I'm going mad, I keep reading the forum and settle on a certain technology and then I keep reading and find out why certain people don't use it and jop to the next chemistry and so on ..

The general consent seems to be that A123 is top of the line, but you never know whether or not you actually get genuine cells. Looking at OSN or victpower they state no price on their website, how does one actually purchase genuine A123 cells?


The 6s 20C Turnigy (LiPo) seems to be another favorite, but if one reads too much ES you get the feeling they will burn down your house in the first night. My place is old and all wood, I think if one cell burns the entire place would burn to the ground. Would charging in a metal container in the bathtub make things safer?


Correct me if I'm wrong and please explain to me why one would choose the Turnigy over the Zippy (LiFePo4) or the other way around. But I got the impression balancing is really important for this one and you shouldn't buy packs that are already paralleled and you cannot simply extend the pack after it got some use as you could with the LiPo, is that correct?


What about LiMn? Seems like many commercial ebikes use this one, any cheap build-your-own-kit vendor for those?

Bottom line, where to buy genuine A123 and how to avoid the LiPo to burn down your house / skin while charging and riding?

Thanks so much!!
 
A123 cylindrical cells, and Headway cylindrical cells seem to be the best imo for performance, durability, safety and longevity. Only negative is the smaller capacity needed to parallel more cells together.

All the prismatics puff, even the A123 prismatics.

In the classifieds a guy is selling new Genuine A123 M1 cells for $6 each. You can get used ones around $4 to 6 each. Also there is a site here in the US that sells them, and larger capacity versions. The headways are priced pretty well and are avaliable on a few sites. I have not ordered from here and have no clue how good they are or reputation: http://www.a123rc.com/category-66-b0-A123RC+ElementCell.html
 
LiMn is a great chemistry, but it has a low C-rate. If you can afford a 20-Ah pack, and can fit it on your bike, I think they are pretty good. ebikes.ca has found them to be fairly trouble-free. 3.7V per cell, so you can use LiPo chargers.

I'm waiting for these guys: http://endless-sphere.com/forums/posting.php?mode=edit&f=14&p=708027

Panasonic, NCR 18650 PD, 2900 mAh, $13 (NCR / LiNiCoAl?)
http://www.ebay.com/itm/Panasonic-N...US_Rechargeable_Batteries&hash=item337f4fe988

Samsung, INR 18650 29E, 2900 mAh, $9 (NCR / LiNiCoAl?)
http://www.ebay.com/itm/Samsung-INR...038895677?pt=RC_Modellbau&hash=item1c2e7afa3d
 
hillyterrain said:
I'm going mad, I keep reading the forum and settle on a certain technology and then I keep reading and find out why certain people don't use it and jop to the next chemistry and so on ..
Basically it depends on:
--your budget,
--your limitations in knowledge/abilities/willingness to learn,
--your system requirements for current/capacity/etc.,
--your available vehicle space to place them and weight limits,
--your patience with personally monitoring charge/discharge or buying the right kind of reliable monitoring system to do it for you, or getting something that is not *as* critical to do that for. (it matters with all of them, just a lot more with certain ones).


The general consent seems to be that A123 is top of the line, but you never know whether or not you actually get genuine cells. Looking at OSN or victpower they state no price on their website, how does one actually purchase genuine A123 cells?
Depends on the kind you want--becuase A123 does not sell directly to the public, (and they dont' actually really exist as such anymore, either), you can't actually know *for certain* that any cell you buy as A123 actually will be. Some places, like EM3EV (cell_man here on ES) almost certainly have the real cells, in good quality, and some other places *might* have good ones, whether genuine A123 or not (like OSN)--but it is a crapshoot with most of those places in China, other than EM3EV.

As for a consensus that it's top-of-the-line, well, that entirely depends on your needs. If you don't need super high currents out of it, NMC like LG Chem and EIG would do just as well, and be lighter, too. And at least for EIG, you can buy them directly from the manufacturer, guaranteeing genuineness. (it'll cost ya, though)



My place is old and all wood, I think if one cell burns the entire place would burn to the ground. Would charging in a metal container in the bathtub make things safer?
Any chemistry can catch fire if something goes badly enough wrong during charge or discharge, or the wrong chain of events happens over time. Personally I keep my (repaired/salvaged origin) RC LiPo in my kitchen oven, closed, and it's in vented ammocans on the bikes. Some of what's in the oven is also in it's own ammocans, and it's spaced out as much as I can get it in the small space. Dead cells or unknown stuff is out in the BBQ grille away from the house. Just in case. ;) (I don't honestly think anything will ever happen, but I have four dogs taht can't escape by themselves if it ever did, so not gonna risk it).

Generally, it ought to be ok as long as you pre-test all your packs to weed out anything questionable, use *good* monitoring equipment that you trust, at cell-level, build your pack up so in the event of a fire it will only take out the pack itself, (even better if it only takes out the subpack that starts it, but that makes your main pack even larger to give that spacing, insulation, and firewall material room).

You also need to size your pack so you have a significant percentage more Wh than you actually need, so you never have to worry about running it too far down--and use LVCs at cell level so that nothing



Correct me if I'm wrong and please explain to me why one would choose the Turnigy over the Zippy (LiFePo4) or the other way around.
It sounds as if you are under the impression that Turnigy is one chemistry, and Zippy is LiFePO4--that's not the case. Turnigy and Zippy are just two "brands", as it were.

In case you're actually asking about which one of those brands has better LiFePO4 cells, AFAICT neither has any good ones. You would want Ping, A123, or *maybe* the Sunthing (IIRC) packs for LiFePO4. *Don't* get Vpower/Volgood/etc packs--they do work (usually) but they suck to have to fix whenever tab welds break or cells die and take the string with them, etc. :( (see my threads on repairing them for examples).


But I got the impression balancing is really important for this one and you shouldn't buy packs that are already paralleled and you cannot simply extend the pack after it got some use as you could with the LiPo, is that correct?
Balancing is important for *all* chemistries, though when they are "new" many types may not need balancing--as they age they will, though, as some cells lose capacity before others, or get higher Ri, etc. Some require an external balancing setup, and some like NiMH and NiCd do it via the main charger leads in an internal chemical process (making a lot of heat).

You can always parallel more sub-packs or whole main packs together for more capacity, evne if it is just by their main leads, letting each main pack's BMS take care of balancing or LVC/HVC/etc. Doesnt' matter what kind it is, other than NiCd or NiMH (those you don't really wanna do taht with).

What about LiMn? Seems like many commercial ebikes use this one, any cheap build-your-own-kit vendor for those?
Dunno--no experience on them yet, but they are a good option from what I have read on ES.

NMC is another good option, but as it is somewhat newer it is harder to find cheap sources of reliable cells or packs. EIG and LG Chem are the only two large-format (20-40Ah pouch) cell providers I can think of right now. The EIG pack I have is nice, and even with accidentally going to 0V on the 3s lighting pack I was able to recharge it and use it normally, with no problems, no fire, etc. so far, in nearly a year I guess i has been since then. I would not have even attempted that with RC packs or other LiCo cells. ;) (I'd've scrapped them, and I re-use just about anythign that still has life in it!)



how to avoid the LiPo to burn down your house / skin while charging and riding?
It's not so much avoiding them as using them appropriately, with the right precautions and proper charging and knowledge. ;)


Linked thread in wiki
http://www.endless-sphere.com/w/index.php/Picking_out_a_battery:_what_you_need_to_know
 
amberwolf needs to get paid for all the time and effort he spends on here :D
 
haha...that'd be nice...but I'm only one of hundreds of active members that contribute and help here. :)

(though, sometimes people do donate stuff to my projects, and very occasionally money to the projects or my dogs' food bill :lol:)
 
Yeah, it's all a bit much sometimes but as AW said, it comes down to your money, time, patience and anxiety.

I'm sure there is a table somewhere, but based on bare cell data for various pouch cells, the following might help:
Cell . . . . . . . . . . . . capacity. . . . . Wh/kg . . . . . Wh/l . . . . real world constant C-rate
Turnigy 20C . . . . . . . .5 Ah . . . . . . . 162 . . . . . . . 345. . . . . ~7C
Turnigy 40C. . . . . . . . 5 Ah. . . . . . . .142. . . . . . . .304. . . . . ~15C
Turnigy Nano. . . . . . . 6.6 Ah. . . . . . . .178. . . . . .378. . . . . ~40C?
A123. . . . . . . . . . . . . 20 Ah. . . . . . .130. . . . . . . . 240. . . . . ~20C
EIG. . . . . . . . . . . . . . 20 Ah. . . . . . . 175. . . . . . . 362. . . . . .~5C

I put a link on the A-spec Turnigy NanoTech as there are so many diffrent kinds of nanotech, most of which offer great discharge, but fairly low capacity. Given that 5C is typically good enough for most e-bikes, and you can get that from prettymuch all LiPo, I figured the highest energy density was worth listing.
 
Step one is to analyse your needs. If you need to go 25 mph for 20 miles, and climb 5-10% grades along the way, a 20-25 amp controller is all you need for that.

That means all you need in a battery is 48v 15 ah of 2-3c cells. Go buy a pingbattery, and ride it 10,000 miles or so.

If you need more, then you might want to look harder at lipo, but just invest some money in a fairly safe place to charge and store them. I've made some pretty bad mistakes in my lipo use, but never had a pack actually flame. Put simply, I payed attention, and when I screwed up and had a pack hot enough to melt stuff, I noticed it and did something. No burned down garage because I didn't just lean the bike against the wall and ignore it.
 
With shipping I don't think HK can beat these for the li ion low price.

http://www.batteryspace.com/LiFePO4-Prismatic-Box-Battery-12.8V-20Ah-256Wh-10C-rate-without-PCM.aspx

Super fast shipping and low shipping prices to USA.

We are testing these and others like them.

So far so good. Waiting for a cell to go weak so I can try and blow it up but none are going weak.

This stuff is for real ? You really can buy new li ion for lower prices than HK and they show up with all good cells ?
 
etriker said:
With shipping I don't think HK can beat these for the li ion low price.

http://www.batteryspace.com/LiFePO4-Prismatic-Box-Battery-12.8V-20Ah-256Wh-10C-rate-without-PCM.aspx

Super fast shipping and low shipping prices to USA.

We are testing these and others like them.

So far so good. Waiting for a cell to go weak so I can try and blow it up but none are going weak.

This stuff is for real ? You really can buy new li ion for lower prices than HK and they show up with all good cells ?

Wow, 2C rated discharge! Of course, nobody ever overstates those figures....

Seriously, some folks can and should make do with something like that. But many of us need more than 2C "rated" packs.
 
I'm on the same boat.. I honestly don't get it why people really wanna go 35mph + on a bike except off roading. If this is for fun I totally get it but then again we see people building 100V 20AH LIPO packs hoping to sustain 35+ cruising. Then they spend thousands of dollars buying big @ss motors and custom lacing and in the end it will not be reliable and bulky and super dangerous.

But then again its good they are moving the economy further :D
 
There are thousands of E-bike owners who use 36V and also are happy with 26-MPH, they just don't post on ES. Most of the posters here are builders who want better than average performance, but...there is a very big market for E-bike kits/batteries that just have average performance.
 
for ba reliable source of a123[cylinder and sometimes pouch 20ah] you cant do better than cellman ..any size or configuration:mrgreen:
 
kriskros said:
for ba reliable source of a123[cylinder and sometimes pouch 20ah] you cant do better than cellman ..any size or configuration:mrgreen:
I don't mean to step on your toes kriskros, we all were newbies once (I still am : P). It took me a bit of time to find 'cellman'. It's not uncommon to assume that abbreviations or short terms will be understood, but they sometimes they aren't. Cellman = cell_man = em3ev.com.
 
Wow, so many useful responses, thank you very much!! I would like to donate some to your dog-food-fund, amberwolf :)

The question came up a few time about the use, money willing to spend and willingness to sit next to it while charging.

I have a daily commute of 1.2 miles, 12-17% incline, 750ft total elevation, I can immediately plug in when I get there, I'd rather not pet the battery while it's charging, it's supposed to make my life easier every day and is not a weekend toy for powering through the hills. So a safe plug and play battery with many cycles of lifetime would be awesome, since that might be cheaper in the long run, I'm willing to invest a little more upfront..

It will be powering the 450W GNG mid drive, it comes with a 20Amp 48V controller and that one shuts off at 38V. I posted this before in the non-hub forum where I was recommended the A123 and turnigy but this forum seems to get a lot more traction in regards to chemistry.


Concrete cell / pack and charger / power source recommendation are extremely welcome!!


Thanks again!
 
Given the short ride involved, I'd be leaning towards lipo myself. If you don't need range why carry a big battery. Charge at home. 12s, using two 5000 mha 6s hobby king packs would be plenty of capacity.

You won't have to pet the pack, or sit watching it. Just charge it in a fire resistant place, and don't fall asleep while it charges. Won't take very long to put in that small a charge. It's not that likely to burn your house down. You just don't do stupid stuff like set it on the couch or the carpet to charge it, discharge it too deep, or let it get holes in the pouches by riding around with naked packs taped to the bike. A pack that small fits easily into a fire safe lipo charging bag.

You could do it with a ping pack, 48v 15 ah, but it would be 3-4 times bigger and heavier, and cost more. That option would give you lots of range for other rides. 10 ah could work ok, but I fear that the hill would pull just hard enough on a 2c rated battery for long enough to reduce it's cycle life quite a bit.

Compromise option would be some higher c rate lifepo4. Hobby king sells some, but A123 2.3 ah round cells would be ideal. Even a pack with just 2 cells paralelled, 32 cells total could be big enough for that short ride.
 
Hi Dogman

Good to see your post. How are those pups. You helped push me over again to using a LIPO pack on my build. I like the idea of a fire proof bag. I may also ad a timer like what I have on the bathroom fan that will automatically turn off the power in a reasonable time. I am bad with leaving stuff on so I need to alarm it for certain. Some sort of heat / smoke sensing alarm/shut off next to the pack may be good also. Seems like the chargers need to be much smarter for this to be safe.
 
If you add a timer make sure the charger doesn't stay connected to the pack for long periods of time. People have seen their packs gone to less than 3V because of this. Just saying.

Then again with such a short commute and steep hills all you need is a pack that can give you that discharge rate. LIPO is your best option here (like dogman said) to be honest. I mean with just 2- 6S 5ah bricks you can make it back and forth. If you fancy a better ride go with nanotechs and increase the amperage. You will climb that hill like a GOAT.
 
450W GNG mid drive. Nice ! :)

Closest thing to a concrete cell I know of are these cells.

http://endless-sphere.com/forums/viewtopic.php?f=31&t=36589

I make them into packs like lipo blocks with balance leads and all and charge them with a nice rc charger.

Discharge them on the bike and use lipo alarms.

They work well in parallel with lightweight 18650 cell extender packs too.
 
I agree with etriker also . These cells can be down to practially zero volts and still survive. Been there done that. The konion from Doc are durable too. But you have to build the pack.
 
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