Zippy Flightmax / Turnigy lipo testing

[mwkeefer]

So I ordered myself 6 of the 6s 5000 MAH 20C Turnigy's. Got them in less than a week, WOW! Shipping at $69 kinda hurt, but even so, still a great price. Of the 2 I have charged so far, they are showing an Internal resistance of 1.3 to 1.6

Now the bad news.

1 Came with a slight puff on an end cell, and one came with a cell at 1.0 volts.

What should I do? Charge and see what happens? Send em back?

Good news and bad news. I got my replacement pack in. I chose to send only the one with the 1.0 volt cell as it really didn't seem all that puffy and I intend to wrap them very tightly. The bad news it cost me $20 to send back and took about 2 months to make the round trip. But hey that's better than getting nothing. Sure would be sweet if they would allow us to send returns to the US warehouse.

Drewjet,

That's freaking brilliant! I honestly hadn't thought of it before. We send it to the USA warehouse, they wait a week until they have enough to send a pallete and they ship it back slow at low cost to them. We get faster refund, they get more sales since the decrease the return cost and turn around time for replacement (once received they can ship from HK new package) - even better would be if they would stock the US warehouse with 5S and 6S packs.

Ive actually got a contact at HK now... waiting for my suggestions on custom sized packs for us eBikers (I had to convince them there was a market) but... I was thinking of asking for a 10,12 and 15S pack in 5AH. These would be better since they would be matched and we wouldnt' get a single 6S pack with a odd spike in impedance.

The real problem I see is not in getting the larger series packs, or getting them in larger capacities (they can do it, waiting for specs on cell size and weight they would use for the packs to see if it serves our purposes) but in the returns part of things. This will take alot of encouragement from the entire community - strong encouragement... but with the proper leverage (a big market who is not willing to wait weeks and spend way more money to return a defective product)... there may be another point of leverage - if youve noted - the comp paypal fees.... paypal is their primary US payment processor, so in essence we could use paypal as a leverage point by complaining that their returns for credit on damaged property is not reasonable. Paypal would more than likely react by refunding us for the merchandise in question... the amount in question, that would exert much leverage since Paypal can stop them from taking US payments.

If you can't tell I've been thinking about many of our issues with HK andf ways to resolve them which would benefit us and HK - still I never thought of them allowing us to return to the US warehouse.

When I reply to the rep asking for my product recommendations - I will broach the topic of returns and possibility of allowing us to return the defective units to the USA warehouse (and for other countries they maintain a warehouse in, I will suggest the same).... lets see how they feel about it before actually contemplating action.

One thing we should as a community (ES) do.... we need to create a new thread where people can report exactly what packs they have purchased, total price for the packs, s&h paid and method and finally how many of those they received were bad. I would like to do this in some form of voting style thread so we could tally the total number and type of packs which we as an online community have purchased to date. I can guesstimate but then there are people like me, methods, hyena, liveforphysics and recumpence - sorry if I left you out - who are buying about 5-20x the average ebikers purchase) - knowing these figures would put us in a much better negotiating position (even just from the point of making a convincing argument) I would include or encourage RC vendors and dealers who purchase these packs to add tehir quantities to the list... the only think I would ask is for honesty... if I approach HK with a # based argument, I must have a reasonable approximation of an accurate count.

If someone else wants to do this... it doesn't need to be me, truthfully I'm really busy but I would do it to help us all!

-Mike

 

[hurricaniac]

Mike,
Thanks so much for your detailed reply. Here's some more info about the pack and what I was thinking would be a workable charging scheme:

It's a 49.2V 12s3p pack (2 banks [in series] of 3 parallelled 6s1P Turnigy 5000mah 20C packs (the $59.95 ones) using 2 of Gary G.'s LVC boards -- a total of 6 Turnigy packs) so wouldn't this give the pack a total of 49.2V 15Ah when charged to 4.1v/cell?

Given this knowledge - we need to look at the C rate:
5AH @ 20C (I think you mean the 20C/30C packs - slightly different, lower internal resistance)
That means in continuous discharge they can provide 100A (they will get warm at this level, hot even) and peaks for a few seconds of 30X5A 150A.

These packs recommend a charge rate of 1C so.. that is 1 x Capacity or 5AH however you seem to be wanting to charge all 6 6S packs so - the question is...Will you be charging them all at once? .

Yes, the whole 48V pack at once -- so at 48V 20A input, I was calculating that the 48V 15ah battery would be charging at 1.3C, a bit higher than mfr's recommendations, hence the lamp cord thing.

Consider lamp cord is rated for use with 100-150w lamps at 110v so (110 / 100) = 1.1A , this is not the limit but really I wouldn't use lamp cord... id use at a minimum 10 guage harness of less than 20'... if you need to run a charge cable from an outlet to the eBike or charging station - please use a 20A rated outdoor extension cord of 20' - the drop will be less and the wires are insulated better to prevent shorting or overheating

Sounds like I should go with lower resistance wire or mod the internal shunt (if I can figure out what/where it is!). The power supply is probably CVCC, but I don't know for sure...I thought about 2 X 24V Meanwell PSUs, but it just seemed like more connections to manage.

Does the original setup with this additional info sound any safer?
-Bruce

Here's my battery scheme (altho Gary's boards don't exactly connect this way):

 

[will_newton]

Mike, I'd rather be able to buy a 6s or 5s 10ah pack than a 12s 5ah pack. there are a crapload more 6s than 12 s chargers out there. series wiring take less connectors than parallel wiring.

anyone can stack more cells together with tape, but cutting the cell count by half is a big deal.

 

[mwkeefer]

Mike, I'd rather be able to buy a 6s or 5s 10ah pack than a 12s 5ah pack. there are a crapload more 6s than 12 s chargers out there. series wiring take less connectors than parallel wiring.

anyone can stack more cells together with tape, but cutting the cell count by half is a big deal.

Will,

While I understand your reasoning... I have found that if I order 6 5S packs, one of the packs always has an odd cell which has far higher impedance than any of the rest in the other packs. That said, I've never gotten a 6S pack with an odd cell (high impedance).

Since they do this matching inhouse, we would get a better product if we got larger packs in series.

That said, there are tons of 10S chargers out there (I think) and there are quickly coming more and more options for 10-12S not to mention bulk charging / balancing options which are very useful.

I would personally rather have a 10S and a 5S pack in series for each 1/2 of a 15S2P pack... in Parallel charging modes, you would recombine 2 x 5S into 1x10S and finally charge as 10S3P. Personally I would just modify a 48v supply or combine 2 36v supplies modified to charge until the first cell hit 4.15. When out of balance, I would charge as 15S till the first cell hits 4.13v and then I would pull it down into parallel mode and charge 3P10S @ 10A balance charge.

The 5 and 6S packs will not go away, they are actually used by RC crowd in 3D choppers, large airplanes and 1/5th scale electric RC cars so I don't think that will ever become an issue and if your preference is to order 5 and 6s packs (my first pack was 10x 3S packs because I thought this would be easier... pack didn't last long) I don't think you will ever find an issue, they will likely be lower cost too.

Since Gary has a balancer / BMS for up to 24 channels and I am sure there are other solutions (not that they are great yet) for BMS but... this will evolve... and trust me - buying 60.00 worth of CC/CV power supplys for 10-11A @ 62v for charging a 15s pack will be not only cheaper but deliver a true 1C charge to a 10AH pack (or more if you do it right).

I use a 48v modified to put out 5.5A (since even my worst turnigy will deliver 5500mah before hitting my 3.3-3.2v LVC) for a carry along charger and it's only 1 piece which fits nice in a trunk bag (small) or pannier bags and will charge the pack from empty (3.3v per cell) to 4.15 in about 2 hours - perfect for portable charging... the dual supply charger is for home and shop charging and is variable from 15-5A right now. So I can rough charge a 15S 2P pack in roughly 44minutes at maximum ability.

Since my iCharger just bit the dust... I don't have any way of balancing other than manual... lucky for me only 2 cells in the pack seem to charge faster (lower resistance?) than the others so I charge them bulk till they hit 4.15 (the 2 faster charging cells)... then I use a manual discharge board (made of an LM317 with output voltage configured for 3.3v) to drive 10 LED lights which have 100ma each consumption at 3.3v - I also put a swiitch on each LED so I can adjust the current drawn from the cell it's attached to (via the balance taps)... Roughly this gives me from 80ma to 1A of current draw to drop the two high cells down and restart the charging process - as I've posted before this is how it seems that the iCharger worked anyway... I'm just doing it by hand until a better solution arrives (in the mail).

I have also contacted Junsi (iCharger engineer) in an attempt to request they design us a charge manging balancer for up to 20S packs and able to handle various charge currents (based on the FETs used) with seperate alarm outputs for Cell Level LVC, HVC and also Pack level HVC, LVC in addition to Difference at Cell level. I have requested a 0-5v output which will allow the balancer, bms to control any power supply (any suitable) to vary the output current without having to shunt inside the balancer thereby causing excessive heat.

At the same time, I'm working on integrating CellLog8s with a bulk charger to control the charge session... one of the things I discovered today is I can use the data stream from the cell logs to get the cell voltages and then I can calculate the difference... but these are also capable of alarming on the difference getting to far... I can use this to signal an interrupt in a master controller MCU and then engage the drain on a cell level - this is much as other (Gary's, Fechters) boards work with a few differences... basically I would be mimicing the iCharger functional charging algorythim.

For the rest of us trying to keep the packs as evenly balanced as possible... our best bet is larger series packs from the vendor since they will be better matched cell by cell.

-Mike

PS: This is just my personal opinion, I am happy to be corrected or have anyone add somthing I forgot.

 

[methods]

Does anyone see any red flags in using the following cheap bulk charger setup for a 12s3p Lipo 15ah (Using six Turnigy 6s1P 5000mah 20C packs)?

- 48V 20A server power supply with 20' of 17ga lamp cord to limit current
- CellLog8s to trigger a HVC device ("Improved simple auto disconnector for battery charging/testing" -- a DIY circuit in RC Groups: http://www.rcgroups.com/forums/showthread.php?t=1131817)

Thanks for any fire alarms you can pull in advance,
Bruce

(My wife made me write this after seeing lipo fires on youtube)

Charging a 12S 3P pack at 20A is no problem.
I charge my 12S 2P packs at 50V 30A
The old days of charging at 1C are over.

That whole thing about current limiting lamp cord... You can forget that.... Unless you really do want red alarms.
Running 20A continuous thru 17G wire is not a wise plan.

Why would you want to limit the charge current anyway?
The packs are rated for 3C charging right out of the box.
I charge mine at 3C and they do not even get warm.

Just make sure they are balanced and no single cell goes over 4.2V
48V is a little low for charge voltage IMHO - I would do 49.2 at a minimum (4.1V)

-methods

 

[Hyena]

Nice work Mike, if you can get HK to start making these packs I know alot of us would be cheering.
It's not exactly reinventing the wheel for them either, so shouldn't be hard to do.

Back a few pages to comments about the size different between turnigys and zippys, I noticed yesterday when a shipment of zippys arrived that they're quite a bit narrower than the turnigys. Length and height is the same but they're width is narrower a full cell. (ie a 4S turnigy is roughly the same dimensions as a 5S zippy)

Also, I've been playing with my PVC pipe and knocked up this 12S2P pack for a friend last night. I cut wedges in one corner, heated up the PVC and bent it over to make a bit of a bottom in one end so there was no chance the batteries could fall out, It's a bit rough but will stop the cells being punctured. The other end is held in using good ole duct tape, although this is more just to cover up the hole and wiring and hold the BM6s in place - the packs and wiring are jammed in tight so nothing is coming lose.

I've been thinking about it and I reckon the neatest way to make end caps for these will be out of epoxy resin, atleast for one end anyway. Cut the pipe to length, sit it flush on a piece of clay or something and then tip in enough resin to fill say the bottom 5mm of the pipe.

 

[Arlo1]

whished I could find this rain gutter in Nanaimo or even on our island for that matter!
How much to cut 4 and ship the to v9r5v4 Canada?

 

[methods]

My 8 new packs came in.

Now I have (32) 6S 5000mah packs

Do I have you beat yet Luke?

I think I have enough to power my Ford Th!nk NEV

-methods

 

[Arlo1]

My 8 new packs came in.

Now I have (32) 6S 5000mah packs

I think I have enough to power my Ford Th!nk NEV

-methods

Or your house!

 

[Hyena]

What a lipo whore

ALSO, Zippy 25C 6S packs are back in stock again and still on sale. 200 in stock, I might get a few on santa's behalf... :lol:

 

[methods]

My price on those is $56.36

-methods

 

[GGoodrum]

I've been doing a fair bit of testing, in the last week, or so, and have found a couple of "issues" that need to be addressed. First of all, I found that although the Battery Medic 6s balancers have 10 ohm shunts, which means they should be capable of 400 mA of balance current, in use the max I'm seeing is around 200 mA. The reason is that they "pulse" the shunts at about a 50% duty cycle. It looks like about one second on and one second off. The little graphic symbol stays on, though. That's why these things don't get very warm, even without a fan. This puts a crimp in my plan for doing shunt boosters for these.

The other big problem I have is the MW supplies' lack of true CC limiting. The throttling logic, which gets triggered whenever a cell's HVC opto is on, does a perfect job of keeping the voltage for any cell from going over 4.15V, but with the untamed Meanwell trying to cram 20A into the cell, the throttling logic has to cut this back to about 1-2A in order to keep the voltage down, way before the cell is full. With a 48V Vicor supply, with true CC limiting, the throttling logic works perfectly. Anyway, Richard and I are looking at some options for improving the throttling function, to make it work better with higher charge currents (15-30A...), but I think we need to figure out how to populate the CC section of the Meanwells, to make them a viable option.

The good news is that with an improved HVC/throttling function, I've been able to simplify the balancer circuits, to cut the required number of parts per channel. I plan to verify this in the next couple of days, and then get some new boards made.

-- Gary

 

[mwkeefer]

LIPO WHORES - all of you!

Hyena - nice box, all I can get here locally is the stuff that actually looks like aluminum downspout in 3x4 largest size at home depot = (... the ridges suck for me... I will find that damn PVC somewhere.

Gary - Excellent news on the balancers / bms boards... I am also working on the meanwells... in terms of populating the CC regulation portion with somthing we can control externally to reduce the output current and allow the balancers to work properly... The plan is to keep a FET in the "resistor" spot and use this to feed current limiting side of the circuit (the error amplifier)... there are other ways available to limit the output current on these... I found half a dozen reference examples over the web where people have modified power supplies based on the IC in the meanwells.. (TL494)

One thing... have you calibrated a meanwell to pack capacity... meaning have you tweaked the shunts on a meanwell to deliver a packs actual current or C rate ie: 5 or 10A maximum?

When I did this with a pair of 24v that I modified and ran in series to charge 62.25 @ 10A they seemed to taper quite evenly once all cells reached the 4v mark.. just an idea it won't fast charge but it may properly charge if setup this way... I would imagine charging a pack in bulk at 1/2C or 5A into a 10AH pack (ie: 48v 7A unit modified to deliver 62.5v max of 5A) should follow a better curve for you.

A side note... if I balance my packs once at lvc resting manually... (I charge lower cells at 1/2A via balance taps until all resting voltages are with .010 v) I can charge them on the meanwell 24s which flow full current (15 or so A for 1.5C) and I can get 4-5 cycles with the 3.3v lvc before they go beyond 10mv out of balance after charge and rest... How far out of balance are the packs your trying to use with your meanwells?

Oh yea: HAPPY TURKEY DAY everyone!

-Mike

 

[liveforphysics]

My 8 new packs came in.

Now I have (32) 6S 5000mah packs

Do I have you beat yet Luke?

I think I have enough to power my Ford Th!nk NEV

-methods

You tie me.

Guess that means it's past-due to make an order You know I can't let you win at anything, anytime.

I think it's time to fit that NEV with a giant brushless motor. Something custom wound with the phase leads comming out in 3 sets of 3, so you can run 3 of your Methtrollers on it. Burst 450amps at 100v into that thing and see if you can get the tires to spin on it.

Maybe just replacing extremely gay SLA's with LiPo will be enough to get it to do burnouts in the wet. It's gotta shave off 200-300lbs off the rear axle of that thing.

 

[mwkeefer]

hurricaniac,

Sorry.. missed ya there, yep it looks like you got it from the diagram.

Don't worry about 1.3C on the Turnigy LiPo... they will be fine, use the same guage wire for the primary charge leads as you use for the controller or 10 awg whichever is greater (use 10g minimum) and leter rip.

Wanting so desperatly to wag my finger at methods for being irresponsible telling people he charges at 3C - I pulled a bunch of test cycles (with proper protection) and guess what - no kaboom, no increase in internal resistance the cells never got warm and the cycles finished uber fast - 30min from 3.3v fast - charging 5AH at 15A (14.9 actual) including full (C/20) CV phase.

Basically I'm telling you 1.3C is no issue 2C would probably be safe... 3C seems safe from my limited testing and though I've seen lots of stuff methods has blown up ... I don't recall a lipo from charging at 3C being one of the crispy critters (I could be wrong, it happens alot).

Nice graphic btw!

-Mike

 

[methods]

You know those packs are rated to charge at 2C right on the site
2C charging is absolutely safe for healthy packs

As far as telling people that I charge at 3C, I am not too worried....
Who else has a 50V 30A supply on hand :wink:

3C is Gangster Status and any nOoB who follows me blinding is sure to end up with empty pockets and burnt fingers.
I am here to push the limits, not to shepard the weak thrugh the valley of darkness

When I first came to this board I was charging at 1C with a busted Lipo charger (RC nerd Status)
I was positive that a Lipo must never be charged over 1C (thanks to brow beating from ultra conservative RC geeks)

Fechter tuned me in to the fact that I could use any old power supply and I could charge at accelerated C rates.

Now I am free!

-methods

 

[mwkeefer]

You know those packs are rated to charge at 2C right on the site
2C charging is absolutely safe for healthy packs

I never noted that... they actually post 2C as max rate - cool!

I assume lower RI = higher C discharge rate and better ability to take fast (2c/3c) charge rates without damage or heat build up?

As far as telling people that I charge at 3C, I am not too worried....
Who else has a 50V 30A supply on hand :wink:

I can think of a few, me included :wink: (paralleled meanwells for 30A)

3C is Gangster Status and any nOoB who follows me blinding is sure to end up with empty pockets and burnt fingers.
I am here to push the limits, not to shepard the weak thrugh the valley of darkness

When I first came to this board I was charging at 1C with a busted Lipo charger (RC nerd Status)
I was positive that a Lipo must never be charged over 1C (thanks to brow beating from ultra conservative RC geeks)

Wow... Me and a few dozen others went from newbie to Gangsta status in span of 2-3 weeks (maybe Im not as dumb as I thought I was, nevermind I forgot "thinking's not my strong suit")

Keep pushing the limits (deviant - now i get it) - we all appreciate it (our fingers and pockets too), leave the meek to everyone (anyone) else.

Fechter tuned me in to the fact that I could use any old power supply and I could charge at accelerated C rates.

Now I am free!

And then you took the time to vet and test that charging process and were kind enough to freely and openly shared your results with all of us..

So on this appropriate day to be... reflective, Thanks to you and Fechter (and Gary and everyone else who has worked so hard to figure this out) for pushing the limits together! (anyone hijacks that and goes into a gaye joke will be seriously thrashed!)

Happy thanksgiving everyone!

-Mike

 

[Hyena]

When I first started with lipo I bought a cheap B6 charger and it blew up after a few months of use. I the learned the ways of ghetto charging from methods and nearly a year later I'm not looking back. So yeah, thanks to Methods, Gary, Fechter et.al for spreading the knowledge and making this gear accessable to us

I pity all the suckers with their 2C lifep04 and 6 hour chargers!
"ooooow lipo is so dangerous, get away from me"
Guns are dangerous too, but that's fine ladies, keep playing with your bows and arrows

BTW, just placed an order for another 4 25C zippys and a few other lipo nick nacks
I noticed HK are also selling another turnigy branded lipo monitor for $10, similar to the BM6 but with a larger illuminated LED display. It looks like a neater package over the BM6 but the display will probably suck a bit more power from the pack if you tend to leave it connected when not in use.
I grabbed one out of interest, I'll report on the accuracy when it arrives

http://www.hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=7367&aff=81978

 

[Arlo1]

When I first started with lipo I bought a cheap B6 charger and it blew up after a few months of use. I the learned the ways of ghetto charging from methods and nearly a year later I'm not looking back. So yeah, thanks to Methods, Gary, Fechter et.al for spreading the knowledge and making this gear accessable to us

I pity all the suckers with their 2C lifep04 and 6 hour chargers!
"ooooow lipo is so dangerous, get away from me"
Guns are dangerous too, but that's fine ladies, keep playing with your bows and arrows ]

:lol:

 

[mwkeefer]

I have to agree with everyone... LiFePo4 may have it's "Safety" chemistry advantages but... 20AH @ 1/2C or less? 4-8 hr for a 10AH pack (depending on charger)... forget that;

i Can bulk load my 2P15S using a pair of S-350-24 meanwells (only one having a modified voltage limit - the other is stock) from empty to full in just about 40 minutes... That will buy me about 22miles of hard riding or 35-40 if I take it easy and pedal along.

Need I say more?

-Mike

 

[swbluto]

I have to agree with everyone... LiFePo4 may have it's "Safety" chemistry advantages but... 20AH @ 1/2C or less? 4-8 hr for a 10AH pack (depending on charger)... forget that;

i Can bulk load my 2P15S using a pair of S-350-24 meanwells (only one having a modified voltage limit - the other is stock) from empty to full in just about 40 minutes... That will buy me about 22miles of hard riding or 35-40 if I take it easy and pedal along.

Need I say more?

-Mike

I love how this thread is turning into a LiFePO4 bash. Note, the chemistry itself isn't limited to low charge rates, it is specific brands (which I'm sure many are insinuating ping). One specific advantage that lifepo4 has on lipoly is its high charge cycle life, which may make it more economical than lipoly in the long run if it is used often enough. For performance vehicles that don't get daily use to relatively deep discharges, LiPo may be a clear winner.

As a specific example of a lifepo4 chemistry that doesn't suck, try a123. Try the next generation. Even try the newest turnigy lifepo4. This sentiment of "Get roughly similar energy capacity lifepo4 at the same rough cost of lipo and then it's worth it" makes me laugh given the longevity and safety advantages. I guess it's quite serious if you're only concerned about your capacity *now* and for the near-term, but it's not a good cost-effectiveness analysis in my opinion if you're thinking of the long-term (Unless you have high confidence energy storage technology will vastly improve in the relatively short term, which may be a pretty good guess.)

 

[Hyena]

I love how this thread is turning into a LiFePO4 bash.

It's not a lifepo4 bash, I think it's just that guys who prefer lifepo4 also prefer men...

anyone hijacks that and goes into a gaye joke will be seriously thrashed!

Sorry...

 

[methods]

(Unless you have high confidence energy storage technology will vastly improve in the relatively short term, which may be a pretty good guess.)

Yes

I paid about $100 only a year ago for the packs I now get for $50
2 years ago I paid more like $250 for "Name Brand" stuff like Thunderpower V2

Hell... I paid $109 each for three 4S 2200mah TP Extreme V2 packs only just two short years ago

Making a 5 year investment in any battery technology right now is a fools move in my opinion
By the time this stuff wears out it will be old news.

But..... Then.... I dont look at this hobby as an "economical form of transportation"
I look at this hobby as a training ground for the real Electric Revolution that is right around the corner.....

The only thing stopping me from converting my car is the price of Batteries.

-methods

 

[momo]

I look at this hobby as a training ground for the real Electric Revolution that is right around the corner.....

The only thing stopping me from converting my car is the price of Batteries.


I'm right with you Methods. Just yesterday a thought of converting my 89 s-10 blazer into electric came though my mind. The thought of the batteries alone very upsetting. Having a 20 year old car for 14years is pretty good though.

 

[number1cruncher]

I found this 3x4" vinyl gutter at Home Depot tonight. $11 for 10ft. Seems to be like what Hyena has, but ribbed.
View attachment 1

Fits two 6Ss side by side with a little room above.