Zippy Flightmax / Turnigy lipo testing

[methods]

I am a bad, bad, man...

I just bought 4 more of the 6S 5000mah 20C packs
They are only $60 !!!!!!!!!!! WTF?

I did it completely on the whim... One minute I was downloading wedding songs and the next minute I was entering my PayPal info on Hobby City

I am going to string those into my 24S 2P pack to make a 24S 3P pack

88.8V 15Ah is one hell of a pack.....

I also picked up 23 more 6S JST-XH 12" balance tap extenders for building stuff.

I hit the 4KG mark right on the spot for the best shipping compromise of price and speed.

-methods

[Hyena]

2 days ago I ordered another 3 of the 5S 5ah packs too.
If all 3 work (got a pack with a dud cell last time ) I'll be able to run 20S2P for a 74/84v 10ah pack

Although the plan is still to build a new bike with the new golden motor magic pie hub and 60v 15s pack

If I get another dud I'll scream the house down. I packaged up my last bad pack to return only to get rejected at the post office because under new laws they will no longer ship anything with lithium in it, not even phone batteries
Had I have known they weren't psychic when they asked if I had lithium batteries in the packet I would have lied...
Ah well, I guess I'd then risk it getting bounced at customs. I suppose I'll salvage the working 4 cells to power my lights or something

[Ypedal]

Lipo Sluts !

[mwkeefer]

I have to agree with ypedal (on more than just the lipo sluts comment)... seriously methods my man, do we need to hold an intervention? As I understand it there is a 12 S, I mean 12 Step Program for this problem... you are not alone = )

Sorry for the humor, just finished a day from HE**... I would get into it but it's so damn confusing that I'm not sure I can even recount it (and I lived it).

Update:
No response from Hobby King yet in regards to:
1.) Loose solder joints (easily fixed)
2.) Broken solder tabs (not easily fixed, but fixable)
3.) One further issue which I won't discuss openly until I hear back from them with regards to an engineering issue (nothing that should affect our use of the packs)

I would also like to give some more info about the packs (mine are all 3S 5A 20/30C) design and engineering and ask that if anyone else can measure and report if they have similar findings...

I was looking at the charts of my battery packs individual cell impedances and noticed an odd trend, on 6 of my packs (some are broken right now, some are just not tested yet) the cells have up to a 3 mohm impedance while others (most) have between 0-2 mohm. All the packs live up to the 4mohm claim so there is no problem there. The potential problem is their distribution within the individual packs, for example ... 1 pack I have measures cell 1 as 0 mohm, cell 2 as 3mohm and cell 3 as 1mohm = 4mohm. By putting the cell with the highest internal impedance in the middle position they have eliminated 80-85% of the cooling area. At the same time they sink the added heat of the higher impedance cell into cells 1 and 3 thereby heating them without cause.

If they put the higher impedance cells at the outside of these packs they would have nearly 50% more surface area exposed to dissappate heat. This would result in lower overall pack and individual cell temperatures and as a direct result, longer pack life.

My question is: Can someone else check this with the 5S and 6S packs to see if this is coincidental or more standard of their assembly process?

Thanks in advance!

- Mike

[liveforphysics]

Mike-

You can't take any Ri measurements on LiPo cells seriously until you've got at least 10cycles on them.

They will often read all over the place, then once cycled a few times, Ri and voltages all settle out pretty consistantly, unless you have a bad cell. Never judge a cell until it's been cycled a number of times though. Your higher Ri cells might become your lowest Ri cells.

Capacity always increases as well. I find a 5Ah zippy/hobbycity cell might have 5,500mAh on it's first 1-2 cycles, and by cycle 15, it's getting a full 6Ah, and I'm not using any different HVC/LVC on the testing.

Since you have a 1010b (very nice choice in charger), set that sucker to cycle mode, throw everything in a big clay pot on your back porch (or somewhere else safe) and set it to run 20cycles, and forget about it. In a day or two when it's finished, swap new packs onto it, and set it to 20x cycles again. Remember to disable the auto-time-off thing, so it doesn't time-out before it gets all 20cycles done. I also set it for fairly shallow cycles, like 4.1v-3.3v, it takes less time, and the cells still get broken-in just fine.

Best Wishes,
-Luke

PS: I am also a LiPo slut. I have around 80 LiPo packs, and I'm around the $13,000usd spent at hobbycity point... RC helicopters and planes are worse than a drug habit.

[mwkeefer]

Luke,

Thanks for the info... I had already determined that lipo needed to be properly cycled 5-10 times before they develop stable characteristics. I have cycled in the manor your mentioned (I used my oven then, it is flame proof) each of the 4 3S packs 8 times before first use on eBike.

I would be doing the same with my other cells to make a 10AH pack (I think the added capacity will make all the difference when presented with 35-40A continuous max) but since 3 of my HK cells are beyond repair (2 broken weld tabs, 1 with a problem I dont even want to mention until I hear back from HK) I can't build my 10AH pack (or my 10S 15AH which is my final power configuration for my lightweight and ultra powered (4+ hp) ebike.

Sadest part is, my company was looking to HK as a vendor for lipo packs (large quantities 200-800 packs at a time, and you guys think your lipo sluts... lol) with 3/10 unusable and 5/10 which had to be repaired (solder tabs came off durring shipping I suppose but packaging was not damaged, eh) and they haven't responded to my emails yet... well, for the company purposes I think the packs would be perfect (if 1/2 didn't require resolder on arrival) even without the cycling they deliver their rated power and then some so they fit the bill... I can tell you they only puff when overcharged, no heat, no flame though I wouldn't want to breathe whatever its venting but I did deliberately overcharge (V and A) one pack just to see what would happen, I was surprised at the lack luster nature of the event.

I don't think we can use them as suppliers though based on their recent shipping issues, response delay and quality control but if they atleast make good on the 3 unuseable packs they sent me... I will continue to order their cells for my own personal uses.

Again thanks for all the info, nice to have expert confirmation = )

-Mike

[Hyena]

Sadly I dont think we can expect much out of hobbycity in terms of warranty without alot more expense on our part for return shipping. They claim to replace and resend a lipo pack that's faulty on arrival, but only after you fork out another $30 odd on return shipping to China. I even offered to video testing each cell voltage, and showing the BM6 alarming and showing the dud cell, but they weren't interested. Return it or nothing. And if you've tried to repair it then don't even waste your time on return shipping because they won't take responsibilty.

Reading on other forums a few people have received packs with one more more cells wired with the polarity backwards. They claim to test all their batteries before shipping but clearly this isn't the case. Yeah ok the cheaply made tabs could break during shipping, but there's absolutely no way they've done any sort of checking/ quality control if they're sending out packs with cells wired in backwards.

[liveforphysics]

It seems you guys have terrible luck, or HC goes out of there way to test every pack they send me, and they always have loads of protection in the shipping boxes.

I might just be on a perfered customer list or something, but the few times I've had issues with various RC parts, I've just sent an email, told them what I wasn't happy with, and they said they would send out a new one to me later that day.

About 3 years ago, everything they sold was offered with free replacement and they covered shipping, you just had to tell them something was bad/broken. I think perhaps people abused this system to the point that they have to demand things to be sent back to avoid fraud warentee claims.

[Ypedal]

Next time i order from there i'm making a video of me opening the box and testing each cell on the spot ! ( may or may not help with warranty, but i'm sure if these start to show up on youtube they may take notice !! )

[GGoodrum]

Luke -- You are truly the centerpiece in a bouquet of LiPo sluts... Even Patrick is a "slut-in-training", in comparison.

-- Gary

[nomad85]

Would it be possible for one of the lipo experts to take some photos of the pack building process.

I am pondering a 3s3p setup of 5cell 5000mah packs(15s3p total) and I would probably use the 350 watt iCharger(8 cell version) to charge all the packs in parallel, but its a little difficult to get my mind around the wiring. Details like, can you leave all the balance taps in parallel when charging as well as discharging, and the best way to swap from series setup to parallel still eludes me. Also the cell monitoring(basic) is somewhat hard to envision, so far I am thinking if you have all the cells wired in parallel, you could use one cell monitoring device to keep an eye on them, unless having them all in parallel is a bad idea, then you would need one for each pack and would have to remove it to wire them all in parallel, needless to say seeing it done right would be a great help.
I'm not a lipo newbie, but I have never wired any packs up together like this.

[mwkeefer]

Hey all,

Still no word from Hobby King, but I am patient (sort of) and have enough for rough testing. Liveforphysics, you most likely are on a preferred customer list... I assume you post alot of commentary on their site.

Their problem will be that I did video the unboxing of both orders, the initial readings (even the 0 volt packs) and finally the charge cycles after repair of salvagable cells.

The shipping containers were fine, each 3S pack was wrapped in bubble pouch, in a seperate white box and then the whole package was wrapped with bubble or filler bubbles (can't remember). Additionally there was no visible damage to the boxes outside and I have learned to refuse shipments which have any sign of physical abuse.

I can only conclude that they do NOT test each cell, the ones I got which had snapped weld tabs could not have happened durring shipping but had to occour durring manufacturing. There is another problem I have been hesitant to discuss here but:

On two of the packs durring the initial charge phase (1AMP charge or 1/5th C) within 30 seconds the packs swelled nearly 10%. Needless to say, I did an emergency shutdown and watched the temps both times and they stayed fine but the swelling continued to about 20% where the first bad pack burst it's foil wrapper (center cells of both 3S packs were the biggest issue) and released some pressure gas.

As I said above, I have this whole experience on video as I was working on a "how to build lipo pack for ebike from Turnigy Lipo packs" video for you tube for those who are into the BYOB style ebike (Bring your own battery). Additionally I have the charge logs (I was documenting the entire process, logging with logview).

In short, I don't want to trash HK and I hope the delay in response is due to the technical nature of the complaint I sent them + the overwhelming amount of raw data and video. I still have hope they will correct this situation or I am looking for a new vendor even though these cells (when they work) are awesome!

With regards to charging I am workign on a simple howto low cost charger based on a 500w PC power supply tweaked to provide 12.44v at cutout. These suplies are 17.00 and can handle 38 Amps max load on the 12v rails (dual). This makes a perfect parallel charging power source for 3S configuration and can handle 12S2P or 3P packs at their 1C charge rate (5A) with no problem.

I will post full plans, acceptible supplies and sources, recalibrating to the proper voltage (change 2 resistors and use 1% tolerance to get everything in order and tight.

I have family over tonight and my son so I won't be follow up posting on last nights and todays testing for regen using any battery chemistry (hint: the 1F low ESR cap idea works!).

-Mike

[Hyena]

Nomad this is very similar to what I have, I'm running 15S2P, made from 6 turnigy 5S 5ah packs
I have soldered my parallel packs together to essentially create 3 5S 10ah packs.
The balance taps are also soldered together, so I have 3 sets of discharge wires and 3 of jst balance tap connectors.
So I what I essentially have is a 6 pin anderson plug leaving the pack. For charging I have a 6 pin parallel lead I plug in and on the bike I have a 6 pin series lead. For balance charging I have a parallel lead to connect to all the jst connectors.
THIS PIC shows my old 12S2P pack made from 4 6S packs.

Mike I'm interested to hear the outcome with HK. I actually spoke to someone on the phone and they weren't interested in any amount of evidence other than us sending back the faulty packs. They claim on their website that they test the packs but she confirmed that they don't test at the warehouse and have no facilities to do this. From what I can gather they're buying them in bulk from the factory they're made in and blindly shipping them out. The factory obviously has no quality control at all, and HK don't seem to care that they're on-selling shit products.

Re: your charging ideas, why in lots of 3S ? That'd make charging a bit fiddley ? Have you seen the threads here on using switch mode power supplies ? They're fairly cheap and come with +/- 10 % voltage adjustment. I have a 24v one that I have set at either 21v or 25.2v for charging banks of 5 or 6S packs.
eg. http://cgi.ebay.com.au/ws/eBayISAPI.dll ... 0443223782

[Grinhill]

I'm a big fan of my 6S1P 5Ah Zippy Flightmax pack, has worked really well for me.

But the need for speed is strong. Last Saturday I ordered four 4S Turnigy packs, and I am going to 8S2P.

They arrived today! I also ordered a Turnigy Accucel-8 balance charger.

Am I correct in thinking the only way to connect an 8S pack for balance charging is to make my own Y-connector (two 5-way male into one 9-way female JST-XH connector)? They don't seem to be available ready-made from any RC suppliers.

So I need to buy the bits from Digikey (or Farnell in Australia)?

[mwkeefer]

All,

I have had it with HK. They don't even have the common civility to respond to my emails and when I get someone in live chat they just go dumb and silent on me. I will be posting the unboxing videos in the morning on youtube and also close up pics of how the cells arrived, testing logs from iCharger1010B and the puffer caught on tape (sounds much more interesting than it is).

I also think I know what happened to them, does anyone else remember they had all the appology notices up about how long orders were taking to fill... we all know what happens when peoople fall behind, they speed (if they have a good set of lipos, not these half assed batch) up and cut corners.

My issue is more one of principal, I pay for somthing... I expect to get it. If there is a problem and it is the fault of the supplier I expect them to promptly correct it. In the case of an event like this (50% failure rate) it is clear they didn't take the time to test the packs before shipping and I have had a number of emails and PMs (and other posts I found) of similair issues within the past month timeframe.

All HK needed to do in my book was ship me 3 replacement packs, I accept the other 2 I receive which had to be resoldered but have been through 10 cycles per pack and seem fine. These were prototype anyway so I don't mind but I do mind not getting what I paid for, eventually. For their lack of communication and quality control (regardless of cause) they have lost my companies first order which was to be 200 units of 6S 5000mah 20/30C packs. Retail is about 11K I would have assumed single order qty discount pricing of around 6-7k + s&h. That was just the opener for the first 50 units my company is producing.

I have inquired with many other chinese vendors / suppliers / manufacturers (16 to be exact) of lipo cells / packs and have found 7 willing to ship us 12 - 24 cells (depending on if rated at 5AH or 10AH) express at no charge. This is how it should be, I just figured HobbyKing had such a good rep and honestly the good packs are great but we can't risk our business on them.

I will report back the results of the new vendor packs / cells and if needed will put together a group buy from one of the better companies. A few of these vendors have been used by an associate (who only deals in batteries) for the past 5 years although not for lipo cells (I turned him onto them), and he has had better than good results with them.

I will get the pics and logs up in the am (i need sleep), the video I have to convert from my dv camera but I will get it done tommorow and post the whole unedited (there is a lot of profanity) footage.

-Mike

[liveforphysics]

With regards to charging I am workign on a simple howto low cost charger based on a 500w PC power supply tweaked to provide 12.44v at cutout. These suplies are 17.00 and can handle 38 Amps max load on the 12v rails (dual). This makes a perfect parallel charging power source for 3S configuration and can handle 12S2P or 3P packs at their 1C charge rate (5A) with no problem.

-Mike

I've done a lot of playing with PC power supplies. I've played with some with a sticker claiming anywhere between 2x20amps, 2x18amps, even 2x25amps. None of them could hold a continous draw of 18amps even with both channels getting combined. Yes, none could hold even 1/2 the rated current, and the PSU with the lowest power rating on the sticker was actually able to hold the most current. Maybe you've found some that can actaully do what they claim, but I've never yet found a PC PSU that was even close to doing what it claims it can do. Those Ebay cheapy "meanwell" brand power supplies are available in a wide variety of voltages, and all are simple to adjust by turning the pot to dial in the exact voltage you want. They are also able to deliver every bit of the current they claim. Pretty good value IMO.

[Hyena]

Those Ebay cheapy "meanwell" brand power supplies are available in a wide variety of voltages, and all are simple to adjust by turning the pot to dial in the exact voltage you want. They are also able to deliver every bit of the current they claim

And then some, my meanwell 24v S-145 is rated at 6 amps but puts out a good 9 amps between 21 and 25v

[cmptrgk]

Hello...1st post

It seems the general direction a lot of people are going is with the larger Zippy/Turnigy packs. Given the nature of batteries and the inevitable failures doesnt it make sense to buy the the 3s 5000mah 20c packs in numbers to minimize loss when a cell goes south? My prospective is that i dont have the time (lacking skills as well) to repair packs.

I'd rather drop in a replacemt pack for $30 than disassemble and repair. At $30 a pack you can keep a couple around for just that...

So I am thinking 4x3s series for a 44.4v 5ah cluster with 2p or 3p for range. so $240 for a 44.4v 10ah pack $360 for a 44.4v 15ah (batery cost only).

Is my logic off here? Does this complicate charging/balancing configurations (i have a Turnigy Accucell 8 charger I use for RC Heli bats)?

[methods]

Running a greater number of smaller pack has its drawbacks...-

- Greater number of interconnections which create more inline resistance, more points of failure, more clutter, and more weight.
- Twice as many balance taps to deal with

I have never had one of these packs fail.
The problem is that they *come in* bad.
If a pack comes in good it stays good.

To each his own though. You should try it and let us know how it works out
Any method for getting lipo on your bike is a good method

For me - the bigger the better! If they sold 10AH 12S packs that is what I would buy.

Of course I have never received a bunk pack either so I am an optimist.

-methods

[liveforphysics]

I feel the same way you do Methy. I only wish the packs came in bigger sizes, but kept these killer Wh/$ costs

This is why I'm still working with trying to get a hookup for the Kokam 70Ah cells. Mmm... 70Ah 24s Kokam cell pack... Mmmm.... 6.2kWhrs of goodness.

[CNCAddict]

Hmmm, since you're a preferred customer at hobbycity....maybe you could pull some strings and get them to make us some HUGE cells. Hobbycity basically owns the production facility (from what I understand). So this should be something within the realm of possibility for them.

[liveforphysics]

Good call. They love me there only because they see me as a cash cow, and they love to milk.

I will talk to them about putting together some grown-up sized packs. I think 10s packs at 10Ah or 10s packs at 20Ah would be great building blocks for making easy to build E-bike LiPo packs. Does anyone else have any thoughts on what an optimal large LiPo pack size should be? I only chose 10s above, because my 12s mega-power RC charger sucks compared to my 10s 1010b charger, so I like to make packs that split into 10s groups.

I will fire them off an email and see what they say.

I will also fire off Kokam another email, and see if they have come down off there high-horse yet. Bunch of dicks in Kokams "sales" department. They act just like A123 when you try to buy cells. I'm not going to quit though, I'm sure if I keep at it, I will eventually find some angle that will work.

[mikehains]

liveforphysics,

I'd be keen on 10s 20Ah packs, or even a number of 10Ah packs. For the next project, you understand.

Regards,
MJH

[bearing]

I have a question which is a bit off topic, but may be of general interest. I'm thinking about buying 24 6s 5Ah Turnigy packs for an electric motorcycle build. The weight of 24 packs is too high for air shipping, it has to be split into 10 kg groups. 11 packs is 10 kg, so the pack would have to be split into three groups. Shipping will be about 20% of the battery value. Since custom fees (and I think also taxes) in my country are based on the total value including shipping, in the end shipping cost will add an an even bigger amount to the total. So, shipping is a cost I would like to reduce.

Have anyone of you had Hobbycity ship heavier stuff than their air mail limit, or got a shipping in a cheaper way?

[liveforphysics]

I have a question which is a bit off topic, but may be of general interest. I'm thinking about buying 24 6s 5Ah Turnigy packs for an electric motorcycle build. The weight of 24 packs is too high for air shipping, it has to be split into 10 kg groups. 11 packs is 10 kg, so the pack would have to be split into three groups. Shipping will be about 20% of the battery value. Since custom fees (and I think also taxes) in my country are based on the total value including shipping, in the end shipping cost will add an an even bigger amount to the total. So, shipping is a cost I would like to reduce.

Have anyone of you had Hobbycity ship heavier stuff than their air mail limit, or got a shipping in a cheaper way?

I might be able to help you save some cash with a large LiPo purchase. I can often get special prices from HC, and even special shipping on large orders. I don't know what country you are in, but I could always send it on to you as a gift, with a declared value of $40 or something. However, it could be that the cost of shipping the package twice could out-weigh the cost savings.

I can assure you that HC will use a customs declaration form that will make you smile when it comes to pay dutys. I've had >$2,000usd single orders, and the customs form said "$38usd of hobby toy parts".