Zippy Flightmax / Turnigy lipo testing

[mwkeefer]

GC,

What's your pack's AH capacity...

Normally the Turnigy Lipo want a maximum of 2C so a 30AH pack would be good up to 60A charge rate for a moment...

My guess is on the limn the BMS steps in and throttles the regen current with PWM below the required maximum...

60A of regen will lock your wheels up... just FYI, even 10A of regen stops me awful quick from 30mph - 20 would throw me or lock my rear wheel 60 would launch me like cannon fodder.

-Mike

 

[GCinDC]

60 would launch me like cannon fodder.

lol. Yeah, I can't believe the current is 60A. I generate max 8A when using regen at 30mph w/ the 9C, and this is a 24V bionx kit... :lol:

Good to know about 2C though. Thanks.

I got impatient and bought 6 x 2.2Ah Blue Lipo packs, so it'll be 6.6Ah. Did you get your Blue Lipos? Are they Turnigy's with a different wrapper?

 

[amberwolf]

From around 15MPH, I get about 5A regen current on a 2807 9C with Lyen controller default settings, and it slows me quickly but smoothly. I can imagine 10A would slam me to a halt pretty quick, and 60A would probably rip the wheel off. :lol:

 

[liveforphysics]

I gotta ask: what's the max safe charge rate for 30C lipos?

At 5C continous charge from empty to full, the cells stay ambient temp and charge normally.

Something critical with rapid charging of lithium cells is to absolutely ensure the cells are not excessively cold when you charge. Cold temperature charging is something that greatly shortens the life of the cells. Ideally, charging when warm/hot is ideal, but in your case, a bionix motor is never going to draw enough power to warm a LiPo cell.

 

[Hyena]

What Luke is saying kids is that if you're going to use lipo you need to man up and have a 100a controller
Or build a seat out of your lipos. This will not only warm them but if they start to get too hot you'll have an early warning system. When your seat starts to feel hot and puffy it's time to hop off. Else KFA will ensue :lol:

I can imagine 10A would slam me to a halt pretty quick, and 60A would probably rip the wheel off. :lol:

Not necessarily, when I tested the regen on my stock magicpie it would output 10-15 amps of regen current down a steep hill (stayed around 10 until almost stopped) with initial spikes of 20 amps and it never felt overly savage.

 

[GCinDC]

At 5C continous charge from empty to full, the cells stay ambient temp and charge normally.

Wow, 5C? I was reading about the lithium 'plating' over 2C, but then it (battery university) said they shouldn't be discharged more than 1-2C either... lol

Ok then, any concerns about paralleling LiPo with LiMn?

The LiMn gets charged up to 4.2V, so getting the LiPo up to 4.2V will shorten its life. But during a discharge, would the LiMn sag more and need 'charging' by the LiPo?

Why all the questions? Working on a pesky solution to the BionX puzzle. And yeah, it's not for me... it's for the wife. She loves her BionX kit, and she won't ride a tank like me. I found out that to make it up the hills back to home on her 4 mile return commute, she'd ride it in regen mode down the hills to work (like riding a stationary bike!). But come the Fall we'll be hauling two kids in a trailer and a third on the child seat...

Or build a seat out of your lipos.

And in this case, we might have to worry about KFV

 

[liveforphysics]

Wow, 5C? I was reading about the lithium 'plating' over 2C, but then it (battery university) said they shouldn't be discharged more than 1-2C either... lol

Battery University wrote up all those pages on Lithium back when the best LiPo you could buy was 4-5C discharge rated...
That site is useful for info on lead acid, NiCd, and that about tops it off. Even the NiMH info shows energy density numbrs at about 50% of where "modern" RC NiMH is now.

Neat site, but battery tech matured and grew-up, and the info on the site never changed.

Ok then, any concerns about paralleling LiPo with LiMn?

The LiMn gets charged up to 4.2V, so getting the LiPo up to 4.2V will shorten its life. But during a discharge, would the LiMn sag more and need 'charging' by the LiPo?

LiMn doesn't explode or do anything wacky if you charge it all the way up past 10v/cell. However, like LiPo, it also shows a very large life-cycle increase when charged only to 4.1-4.15v. More of a life cycle increase even than LiPo.

 

[Hyena]

Or build a seat out of your lipos.

And in this case, we might have to worry about KFV

KFV ? Are you still talking about a bike for your wife ? :lol:

 

[GCinDC]

KFV ? Are you still talking about a bike for your wife ? :lol:

I knew I shouldn't have gone there... But yeah, I'm talking KFV for the wife.... Considering LFP's tests, maybe it'd just be a warmer... something she'd probably love!

Why, would it be KFD for your wife? :lol: :lol: :lol:

 

[GCinDC]

LiMn doesn't explode or do anything wacky if you charge it all the way up past 10v/cell. However, like LiPo, it also shows a very large life-cycle increase when charged only to 4.1-4.15v. More of a life cycle increase even than LiPo.

That's exactly what I wanted to know. Thanks, Luke!

 

[ZapPat]

Or build a seat out of your lipos. This will not only warm them but if they start to get too hot you'll have an early warning system. When your seat starts to feel hot and puffy it's time to hop off. Else KFA will ensue :lol:

"KFA" could also be called "flame hoop"... and in this case it would not be the result of eating too much salsa the previous day!!

I can imagine 10A would slam me to a halt pretty quick, and 60A would probably rip the wheel off. :lol:

Not necessarily, when I tested the regen on my stock magicpie it would output 10-15 amps of regen current down a steep hill (stayed around 10 until almost stopped) with initial spikes of 20 amps and it never felt overly savage.

An equal amount of regen current and drive current will yield similar torque, just in opposite directions. I guess we expect instant and possibly brutal accelerations on ebikes, but instant and brutal on/off decelerations are a bit more unnerving! We really need some good linear ebrakes on these ebike controllers instead of the all on / all off ones we have now.

Pat

 

[GCinDC]

We really need some good linear ebrakes on these ebike controllers instead of the all on / all off ones we have now.

Do infineon controllers support linear ebraking? This would be nice! Although any electrical/mechanical failures could be ugly...

 

[gtadmin]

We really need some good linear ebrakes on these ebike controllers instead of the all on / all off ones we have now.

Do infineon controllers support linear ebraking? This would be nice! Although any electrical/mechanical failures could be ugly...

http://ebikes.ca/store/store_controllers.php

Edit: It appears that they now don't sell the variable regen models, sorry guys

 

[ZapPat]

We really need some good linear ebrakes on these ebike controllers instead of the all on / all off ones we have now.

Do infineon controllers support linear ebraking? This would be nice! Although any electrical/mechanical failures could be ugly...

http://ebikes.ca/store/store_controllers.php

I meant linear ebraking action via a regular style brake lever, one set up in the same way as a hall throttle works (not all on/off using a microswitch as usual, but instead linear output via an analog hall sensor). ES member wrobinson (Wayne) has already done this using his own controller design... and he says it can brake pretty hard if needed almost all the way down to standstill. This confirms that the ebraking action doesn't have to stop at 4~5kph as it does on infinions/XC116's and similar controllers.

Controlling the ebrakes via the regular throttle suck in my opinion, and might even be a bit dangerous. It's better to keep the brakes/ebrakes on the brake levers only IMHO.

 

[gtadmin]

Yes, I agree, sorry I misunderstood

GT

 

[amberwolf]

I can imagine 10A would slam me to a halt pretty quick, and 60A would probably rip the wheel off. :lol:

Not necessarily, when I tested the regen on my stock magicpie it would output 10-15 amps of regen current down a steep hill (stayed around 10 until almost stopped) with initial spikes of 20 amps and it never felt overly savage.

But what did it draw doing a high-torque acceleration? I'd expect that a similar current during hard wheel-slipping acceleration would also be generated during wheel-skidding braking.

Well, actually, maybe not--since it is upping the voltage on the braking above the level that acceleration would receive, the braking *current* would be lower to give the same power.... This could get confusing. :?

 

[GCinDC]

I love Hobby King, but FYI: I'd have never thought it'd be cheaper to buy domestic...

Placed HobbyPartz order last Friday, June 4, shipped Tuesday, delivered Friday, June 11 in a large box w/ tons of bubble wrap (each pack individually bubble-wrapped, not that I get off on bubble-wrap...)
View attachment 1
- HobbyPartz Price: 6 x 4s 20c 2200mah Blue Lipos @ $18.70 + $4.95 standard shipping = $117

For comparison:
- HobbyKing Price: 6 x 4s 20c 2200mah Turnigy lipos @ $17.95 + $36.79 EMS express shipping = $144.49 (or $28 for air parcel)

No idea how the Blue Lipos perform yet. And granted they're out of stock of the bigger stuff. Actually talked English to someone there too, just to confirm stock...

 

[mwkeefer]

Greg,

The blue lipo were a dissappointment... they give about 4.5AH of capacity when charged to 4.16v and that's driving them down to 3v... Also their under load voltage (load 4C and 7C tested) drop is rather high... now having just received my sacrifical order of 6S Flightmax Lipo from Hong Kong!

YES YOU READ ME RIGHT, I GOT THE SACRIFICAL ORDER THIS AFTERNOON... STILL PENDING MY "LOST ORDER" but it's moving!

So back to the point, they seem to be just true 5AH rated but I think the 20C bit is a stretch, sag would be SICK!

That said, a few in parallel would work for most e-bikes and they are a bit smaller than the Turnigy packs (quite a bit side by side)...

I have discharge logs from my last testing but it was on the Dahon and I succeeded at about 4.2 kw input to that plastic geared motor to melt the phase lines together somehwere... because the resistance is even not choppy I know it's all 3 phases shorted together instead of just 1 - pointing to the wires going into the hub not the windings (they wouldn't have shorted all 3 phases normally).

I've not tested the Zippy Flight max yet (just charged them up this afternoon) but they seem much more akin to the Blue Lipo size and I would venture to guess at this point, the Blue Lipo are rebranded (reshrinked) Zippy Flightmax or equiv... but still not good enough for a single P pack really (imho).

-MIke

 

[evblazer]

For many here 4-7C is junk but I have mostly been running 10-15 amps max so they might not be too bad for a very small assist only pack. I hope one of yah blue lipo folks can find someway to use them longterm and see how they do after a number of cycles.

 

[GGoodrum]

I definitely plan on trying theses, just as soon as the 6s-5000 packs are back in stock. I'm going to make a 24s3p pack for my wife's 5304-equipped bike. This one has a standard 45A controller, so even if these are only 10C packs, that's still plenty of "cushion". A 15Ah configuration would still do 150A, which is 3-times what is needed. Hell, this would probably do fine on my bike, which has a 100A/100V controller and a 5304. Sure it might it might sag slightly more than the Turnigy-based pack that's on there now, but not much. Even at 10C, these will dip a ton less than anything else, including a123s. I think Mike is being a bit too negative. Need to keep perspective.

-- Gary

 

[mwkeefer]

Gary,

I suppose you are right ... I am a bit spoiled but then again looking at size in comparison to the Zippy or Turnigy, I see why the Turnigy out perform the rest... they really are larger, not huge but larger...

I will add I pulled 4.5A out of a single 15S1P pack charged to 4.16 at 1/2C, when I pulled them off all cells were above 3.2v and ranged from 3.2 - 3.4v so just about done... I have the pack level LVC on my Specialized set around 50v with a 2v tolerance so it worked out perfectly to protect this 15S pack (no cell level yet, just testing).

Maximum current was 35A so call it 5C... Dip wasn't great but again this is 5C against a 1P and really I should do a charge and discharge test between 4.2 and 3v just for reflection...

Don't get me wrong, I like the size... I really do, for some of my builds the size factor alone will be an influence - much of the time I build using multiple packs in seperate locations but paralleled together before controller.. it's not optimal for power distribution but it works well for weight balancing... Great for the quick run out to the store, heck on the geared rear (which I just finally damaged) with the Blue Lipo 15S pack (no problems) avg speed (not accounting for stop signs) would be 25mph and it all fit neatly into the requried locations as a 1P 5AH pack with 10mi range (if I don't pedal at all) @ 25A limit (bullet proof).

Oh well... When the 6S come in I too will be ordering them, looking to build up a 24S2P pack in as tight a space as possible and I do like the see through shrink wrap.

-Mike

 

[liveforphysics]

We should make a little conversion factor for the usable/useful $/w-hr difference between the two brands to aid in folks trying to calculate which is the best value/option for a given application.


As an example with some numbers picked just to make the math easy, lets say your application is using perhaps a 50amp controller and a 50v pack (pretty typical stuff?).
Would it make more sense to go with the hobbytown blue packs or the HobbyCity packs?

What about if it's a 25amp controller at 50v?

What about if it's a Methods controller and you're going for maximum performance with 100v and 100amps?


For example, in a given application, if your pack drops from 50v to 44v (just an example) with the blue packs, but only drops from 50v to 48v with the HC packs, and the HC cells gets you 5.2Ah (just an example) and the blue cell gets you 4.5Ah (just an example), then despite both packs perhaps having identical numbers/specs on paper, then this example works out to be a 20% difference in the watt-hours you get to use between the two identically labeled cells. 20% difference is kinda a factor in pack choices and estimating $/watt-hour values between different cells when all labeled as "6s5Ah 20C" (or whatever) packs.




mwkeefer- It's a good think Mdd0127 didn't order those blue 5Ah packs, and then discover they only did 4.5Ah... They would have a Visa fraud case charged against them and a charge reversal, a BBB fraud claim for the over rated "C" rate, a lawsuit for false advertising the 5Ah capacity, and of course reported to shipping companies for not meeting safe lithium battery shipping practices because the bubble wrap on the bottom was popped and no-longer padded on all sides... LOL!

 

[mwkeefer]

Luke,

You only forgot the complaining and posting to every thread with a matching keyword on any forum he can find, including here! - lol

-Mike

 

[Hyena]

It's a good thing Mdd0127 didn't order those blue 5Ah packs

Yeah I reckon, sources indicate that this is is a photo mdd0127!

:lol:

 

[mwkeefer]

Hey ALL!

Great news - my MIA/Limbo package ordered on 5/22/2010 from HobbyKing via EMS finally arrived at my door about 3 minutes ago... shrink tube and 6x 6S 5000mah Zippy Flightmax packs... all seem to test fine and are sitting in parallel on the charger as I type this up...

So it took 20 days or so to get here, but it arrived and now (since I placed a sacrifice order) I have a total of 12 shiny new 6S 5000 mah Zippy Flightmax packs - whoo hoo! Say hello 18S3P pack!

I should add that I placed another order yesterday for a new OSD (time for some video overlays of all the testing I do) and a few misc filler packs (2S, 3S just to make up strange locations for installation) and it actually left the warehouse same day (well for them it may have been a new day, last night) so it seems as if things are indeed running smoothly again!

-Mike