Zippy Flightmax / Turnigy lipo testing

[swbluto]

to me it's the 450 gram limit that is bogus. :?
Would've cost $37.00 to ship my package US priority mail.
I actually think hobbycity may be one of the few companies that make money shipping.
OR
I guess I could've paid over $300 for one 6S 5000mah lipo at my LHS. Sure it would've been a ThunderPower, but at the amps I pull it would have been major overkill.

Somehow $65.00 shipping from hong kong in three days for a rock bottom price battery seems OK. I got 4 for the price of one and it's delivered to my house with no sales tax.

I almost felt guilty about buying from HC vs. visiting my very friendly LHS I've been going to for 20+ years. I even spoke to my local owner about HC. He said he is going to start carrying a line products (plane engines) direct from China and can understand why I shop there for some very specific items.

I may be mistakened (I probably am, I don't have a specific memory of how my product was shipped), but I thought they shipped by Fedex? I don't understand how else you could get the package so quickly. If it was Fedex, than I might understand why the shipping is relatively high.

It wouldn't surprise me if they made money on shipping though. It'd explain how they could keep their nominal prices relatively low.

 

[mwkeefer]

HobbyKing uses the following for shipping:

1.) EMS - Hong Kong Post
2.) USPS
3.) UPS

Over the past months I have ordered 24 or so 3S turnigy packs, 10 6S packs, 12 5S packs and a few of the 30C packs for testing.

All were sent via EMS and took anywhere from 3-7 days to arrive at my location in the USA.

I don't know about USPS or UPS but they do make a % off the EMS shipping. Actually your paying for S&H and they are charging you for the "Handling" but yea... they are taking a bit off the top (if you check actual US EMS pricing for the weight and destination), nearly 50% of the S&H goes to HK.

Hope it helps,

-Mike

 

[ktm_paul]

Just got 8 5aH 5S packs of 20C Turnigy LIPOs from HC (10day delivery by airmail to UK). That makes 12 now - ill rig up a 74V x 15aH pack with them and go for a quick test ride!

Funny thing was - the connectors are now male/female (previous 4 packs were female/female) - bar one which is female/female. Not sure why the did this but I guess that new stock is male/female.

Checked all packs - voltage either 3.85 or 3.86 for EVERY cell. No physical damage bar one cracked red plastic cover on the 4mm gold connectors.

Any idea how to remove those plastic covers? Just pull? Also - where can I buy them (prefer in UK). My 4mm connectors didnt include the red plastic shield with them.

Thanks, Paul.

 

[mwkeefer]

The red plastic shields are likely worthless to you.. I just shrink wrap the to the top of the female side and also to the butt of the male 4mm plug. When assembled it forms electrical connection.

I hope I posted earlier about the Male/Female bit... new stock is coming out (the next 800 or so atleast) with Male plugs on the Ground Discharge plug and Female Plugs on the + Discharge Plug. If you got one that was FEMALE | FEMALE, it was left over from their old stock... keep an eye if you notice any differences in the performance or longevity... I only have 1 new cell (but I have another 15S2P worth of 5S on order.

-Mike

 

[Hyena]

You can buy the plastic covers and male / female plugs from hobbycity too. I bought a bunch when I ordered mine but unfortunately all my packs have both female plugs so I needed to use 2 sets of plugs (they come as one male and one female) to get the 2 male plugs and throw away the females. Oh well.
http://www.hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=9283&Product_Name=HXT_4mm_Gold_Connector_w/_Protector_(10pcs/set)
$2.80 for a 10 pack is a good price, I think I paid around $1 ea when I ordered mine a month or 2 back


My balancer blew up last week so the last 10 charges have been straight from my power supply. I only discharge about 6-7ah from the 10ah pack on my commute to work but so far the furthest the cells have gone out of balance is 0.03v

On a vaguely related note, that 15 amp power supply I posted about earlier arrived today. I fired it up and found its putting out about 17a which is what I expected given my previous one puts out 9 amps while only rated as 6. The only problem is the voltage adjustment doesnt go low enough, the range is 22-30v (previous psu was 20-28v) so I can't use it as a intended for a 5S charger fast charger. Pooey
Time to open it up and see if I can add some extra resistance to the v adj pot to get the voltage down.

 

[ktm_paul]

The red plastic shields are likely worthless to you.. I just shrink wrap the to the top of the female side and also to the butt of the male 4mm plug. When assembled it forms electrical connection.

I hope I posted earlier about the Male/Female bit... new stock is coming out (the next 800 or so atleast) with Male plugs on the Ground Discharge plug and Female Plugs on the + Discharge Plug. If you got one that was FEMALE | FEMALE, it was left over from their old stock... keep an eye if you notice any differences in the performance or longevity... I only have 1 new cell (but I have another 15S2P worth of 5S on order.

-Mike

thanks - do you have a picture example of finished product?

oh - and is there a good way to get the plastic shields off?

 

[Hyena]

Just a quick follow up for those playing with power supplies like THESE. I pulled out the v adj pot and found it to be 800ohms. Ratting through my box of parts I found an old dead multimeter that had a 1400ohm pot in it. Bingo. I soldered it in and now have a voltage range of 19-30v. On this particular unit 1070ohms gives 20.7v which I use to charge my 5S packs. Great success!
If I ever go back to 6S packs I might solder up a switch with a few fixed resistors in it so I can simply switch from 5S to 6S voltages.


Re: the plastic shields, I don't think they're meant to come off. Cutting them would be the best way to remove them

 

[Hyena]

One of my 5S packs died yesterday
Out of the 9 turnigy packs I've bought, that's 3 now that were faulty in one way or another. NOT very good odds! One arrived with a cell DOA, one arrived fine but 2 weeks later having not been used or charged it'd puffed slightly. The 3rd one I've cycled about 20 times, charging to only 4.16v/cell and typically only pulling 6-8ah from a 10ah pack. Yesterday riding to work I noticed I suddenly lost acceleration, then looked down at the wattsup meter to see pack voltage was 42v (15S pack, LVC should be 45) I dont have a BMS or LVC because this is my test rig I've ended up riding to work a few days a week and because I usually only use 5ah getting to work I'm not stressing the batteries so it's not been an issue. I'd only used 4.5ah from a 10ah pack at this stage.

Anyway, I checked the dud pack and found the cell voltages all around 2-2.5v. Bugger. All the cells in the other packs were reading 3.9v. The second I hooked up the charger they all jumped back up to >3v/cell and seemed to recover completely charging back up to 4.16v/cell and holding the charge for the rest of the day. I thought maybe one of the charge wires to that pack came off the night before (I charge my 5S packs in 6P ) but apparently not. I rode home and again got to around 4.5ah and it suddenly died. I gave it a good charge last night with all cells balanced to within 0.02v and being a glutton for punishment, rode it to work again. I kept a close eye on the BM6 and all cell voltages read well most of the trip but again it suddenly died right around 4.5ah. It looks like my 5000mah pack has become a 2200mah pack!

 

[mwkeefer]

Hyena,

That sucks... considering all the issues you have had surrounding the Turnigy Lipos, balancers, and using these power supplies to charge 5S6P at once... Too many variables to really assert that the LiPo is the issue.

I had a few doa cells and two I have fudged in the time since my first order (both on accident, both fully recovered) but my primary pack (15S2P - Charged as 6S5P) has served me well and is now on cycle 45/50 (I have to open the charge logs to tell for sure but the last I checked over the weekend past I was at 42... I think I have done 5 cycles since but not 100% sure.) my life at the 42 mark (I measured and discharged all the packs) is minimal 11.8 AH from a 10AH pack which I charge to 4.17v and cutout between 3.3 and 3.2. Dont ask me how (except that maybe because I'm charging at a bit below 1/2c on average) but I assume it's the iCharger working correctly = )

For the person asking about a good way to get them off... you can:
a.) Use a pair of tin snips and shear them up the butt or...
b.) Do as I did and just cut the ends off! - All my sub packs have short leads of approx 1", only my discharge output leads have 4" still.

Another termination option (for those who are not faint of heart) is to open the packs and actually use a soldergun to heat and remove the 10G and replace with a 4MM gold female connector. This works well to eliminate cable mess and confusion or miswires and Kentucky Fried Finger. I just stole the idea from the flight max hard case LiPos... Once you remove the 4" 10G wires and put the gold connectors on... shrink wrap it up and poke holes for the + and - tabs.

This is a design I played with for a while and like very much but for most it is impractical.

-Mike

 

[methods]

I really am surprised to hear all these stories.
I have purchased (24) 5000mah 6S packs and not a single problem.
I have also purchased countless smaller RC packs.

I have thousands of miles on many of my packs - hard miles charged at 2C with no balancer and and just a 100V power supply.

One thing I will say: If the BM6 is attached while discharging / charging and you are within earshot there should never be reason to step outside of LVC/HVC.
If you find yourself with a 2.5V cell then it is a procedural issue, not a battery issue. (unless of course - it comes like that out of the box)

-methods

 

[Hyena]

I'm totally blaming the cells and not my ghetto set up :lol:

Yeah I'm running a risk with no BMS and largely looking at the total pack voltage to gauge when I'm empty (which I've only drained once) but the fact that 5 of the 6 packs I'm using are fine and it's only the one thats crapping out early tells me it's a faulty pack and not what I'm doing. I'm not doing anything different to you methods (no balancer of late and charging from a power supply). Re: the BM6, I only have one at this stage which I now have connected to the suspect pack and all voltages *were* ok until they suddenly died very prematurely. They basically dropped from 3v to 2.5v on 1/4 throttle in the time it took me to get across and intersection and stop. The recovered to 3.1v by the time I got to work and tested them.

I'm pretty easy on my charging and discharging too. Discharge is 4C max, usually around 3C and when I charge in 6P it's only around 0.3C. It's not fair methods, you abuse the shit out of your batteries and ride around with cable tied on V brakes, and I get all the failures :lol:

 

[mikehains]

My Turnigy 8 x 5S 5000mA (as 10S4P pack) are brilliant !

I have them permanently paralleled (after lurking forever, and PM'ing people for help) and charge them "Pirate" (on a Meanwell RSP-1000-48). I run a fuel gauge when using them, to monitor balance and remaining charge. I use BM6 when charging.

I don't run them anywhere near 3.0 volts when discharging. I seriously over-purchased with the pack. Way more power than I needed.

All results I've had with them have been A+

 

[mikehains]

I've posted videos of the Turnigy's in action: http://www.endless-sphere.com/forums/viewtopic.php?f=12&t=12875

 

[mwkeefer]

Hyena,

There is the issue...

> They basically dropped from 3v to 2.5v on 1/4 throttle

I assume that's after the 4.5ah lifespan?

What are the individual cell voltages of the entire suspect pack at end of life?

Why are you using throttle with a cell @ 3.0v? These fall off the map that low (in my experience). If youve been sucking them down below 3v (you may have been) then you have essentially pulled the old SLA Deep Cycle treatment. As I posted, I've done this twice because I couldn't hear the BM6 going crazy but both times well past the 5000mah rated capacity (first time was about 5200, second and last time was 5630mah discharged from a 5AH pack) but even then I only saw 2.7 - 2.9. Even at that voltage, those packs were brought up for an hour each outside the house in a fireproof enclosure at .5a or so (1/10th C)... then I left them 24 hours and measured their hold... they seemed fine, discharged at 5A to 3.2V cutout and charged back up at 1/2C then resumed normal operations with them.

Point I am getting to is when you see 3.2v at a cell level, it's time to back down... Once you solve the bad pack issue and replace it, you should pick up a few more BM6 units and monitor all packs when in charge/discharge mode. I would set the lvc at 3.3v per cell for the BM6 and just ride through the beeping... drop from 3.3 - 3.2/3.1 and CUT OUT!!!! I would never intentionally run these below 3.1v per cell and normally my packs never see lower than 3.3 (actually I normally never go past 3.7v but that's a matter of capacity and load more than the cutout).

A note on the BM6 units... they are not SET IT AND FORGET IT units, I have found HVC variances of as much as .25v across them (signifigant when we want 4.2v cutout not 4.45v!)... Always check the BM6 monitor to ensure the displayed voltage is accurate with either a good charger or a high end DVM - go to radio shack with the BM6's and a lipo pack and test the pack with the RS DVM and write down the voltages then check each BM6, recording the variances... This will help with the LVC since you can scale it but... for HVC it seems if you have a buggered BM6, send it in. Of the 18 I now have and use durring discharge 1 unit has been off on the HVC side and 2 were off on 1 or more cells on the LVC.

-Mike

 

[Hyena]

Yeah I'm going to set my BM6(s) at 3.2, as you say they drop off pretty fast towards the end once the voltage starts falling. I never bothered changing it from the factory set 3v as prior to this I'd never gone close to it.

Well, I found the problem...
I have 2 spare 5S packs, so I removed the old dead one from my 15S2P pack, crimped on some andersons and duct taped it back into the long 'tube' battery pack I'm currently using (2 wide, 3 long for a long thing pack that runs along the top bar of the bike)
Charge 'er up, ride home get to 4.8 ah and bang, BM6 starts screaching again. And then I realised, it's only since I reconfigured the packs and terminated on an 8 pin anderson cluster of connector that I've had the problem. Unwrapping a few layers of tape on the side of the road I found that when I slid all the andersons together one of the plugs was in the wrong order. The 8 pins leaving the battery pack are 5S 10ah 5S 10ah 5S 5ah and 5s 5ah, so I can either run 15S2p or 10S3P depending on which discharge lead I plug in. With one of the plugs around the wrong way I ended up with 5S 15ah, 5S 10ah and 5S 5ah in series and it was the 5ah pack that was hitting a wall quick. I should have realised earlier when it was doing it around 5ah. Ah well, problem solved, and hopefully there isnt any long term damage.

Not happy with one stuff up in a day I accidently grazed the leads together of the 5S 10ah pack while reconfiguring. Big spark and a nice burn in the contacts as you'd expect, but should be no biggy right ? A quick test with the BM6 reveals 3.9v/cell on all cells, all closely balanced, good, pack voltage 15.6v, whoa what ? Both 5S packs are now only reading as 4S! I tested the discharge leads with the multimeter and got no voltage so I pretty much knew what had happened. It blew in the same spot in both packs, the solder there is quite a bit thinner that the rest of the joints so it looks to be a weak spot. These are the 20-30c labelled packs too.

 

[vanilla ice]

Fusible link ftw!

 

[will_newton]

http://www.rcgroups.com/forums/showthread.php?t=932319

i can't remember if this link is in this thread, but damn, this is an awesome thread on lipo's especially for paralleling them up to make big packs for charging/discharging.

 

[johnrobholmes]

Update on my packs I have been beating. I have a 18s2p pack that does my power duty. 12s2p has close to 100 cycles on them now, and the other chunk has about 15 cycles. All running strong, all stay in balance of each other within .02v or so. I do give a full charger, but generally do not go more than 80% DOD.


Seems that these are a great value for me.

 

[methods]

It's not fair methods, you abuse the shit out of your batteries and ride around with cable tied on V brakes, and I get all the failures :lol:

I have a hard fast rule that everybody here should listen to....

When your resting voltage is equal to or less than your rated voltage you are close to the end!

I never continue riding "out" past that point...
When my 24S pack hits 88V -> that's it buddy, I pack it up and ride home at 1/4th throttle.
LVC is at 72V but no way in hell do I get close to that.


And as far as the comment about the BM6's -> I disagree. I have never seen a BM6 anywhere near being off by 250mV. Ever. You must be thinking of a different brand of battery monitor, otherwise I will need to see proof

-methods

 

[liveforphysics]

That is the beauty of a properly designed LiPo pack. They have a fuseable link between each cell, so you don't damage the battery, hurt yourself, or start a fire.

I'm glad you got your pack issues figured out, and I'm glad it was user error rather than some fault of the batteries. They are pretty damn good batteries IMO. I've got more packs than Methy, and I've still never got a bad one sent to me, or had a pack fail that wasn't directly my own fault. Very pleased!

 

[GGoodrum]

Not having as many multiple packs in parallel as I thought I did was the reason I did the LVC-only board in the first place. I killed a whole pile of a123 cells.

I agree with Methy that it is extremely unwise to have different charge and discharge configurations. You will have an incident, at some point.

So far, my first six 6s-5000 20C Turnigy packs are holding up just fine. I've been purposely getting them out-of-balance, to do testing on my balancer circuits, but they seem to get right back within 10 mV of each other, or so, and stay that way. I have another six 6s-5000 packs, but I haven't done anything with them yet. Actually, tomorrow I'm going to configure them into an 18s2p 67V/10Ah pack for my latest test setup, which is a 9x7 9C on my Mariner 20" folding bike. This bike also has one of Methy's 100A/100V 18-FET controllers. I tried this setup with the 12s3p pack, and with a current limit of about 55A, the acceleration was actually quite peppy. I think I was hitting about 2600W. Top speed was pretty limited, though, on 12s. I think only about 20 mph. I'm not so concerned about the top speed, though, as I will do the delta-wye mod to this motor.

-- Gary

 

[Hyena]

That is the beauty of a properly designed LiPo pack. They have a fuseable link between each cell, so you don't damage the battery, hurt yourself, or start a fire.

Oh, they're supposed to be like that ? Good thing I didn't heavily solder it up to repair it... *whistles*
I feel like homer simpson lately :lol:

As for charging mistakes, they should be almost impossible* with my andersons setup.

I have one plug like this for 15S2P discharge, one for 10S3P discharge and one for 5S6P charging.



* watch me turn around and burn my house down next week :lol:

 

[will_newton]

I like the idea of being able to switch adapters to change the configuration as needed. Neat idea!

 

[methods]

Yea - if you are going to do a different charging / discharging configuration that is about the smartest way you can do it.
Anderson connectors are great that way...

(but a better way is to not change the configuration )

EDIT:
DELETED TO AVOID ANOTHER DISCUSSION ABOUT SAFE

-methods

 

[vanilla ice]

I miss that dude. The more I think about it, the more awesome I think his fast & cheap bikes are.. especially given his state's peculiar laws and his budget constraints.