Zippy Flightmax / Turnigy lipo testing

[johnrobholmes]

I figure quite a few people are using these packs, we should collect our experiences in here.

I have about ten of the 5ah 6s Zippy flightmax packs in both 15c and 20c discharge rates, and have 6 of the new Turnigy 5ah 6s packs on the way. After about four months of riding on them I must say they are a great value. The soldering jobs are not always the best, but for the cash it is hard to beat. The one drawback is when they get close to full discharge, around 85% DoD, the cells start to really get out of whack. I rode last night and was just hitting the end of the pack when I got home (typically I will have at least 20% pack left). When I let them rest and plugged them in the two 6s packs I was using were a full volt off of each other. Typically they are dead on even. Voltage difference was at most .2v per cell on each pack, quite a bit larger than I like to see. Because of this I will run my LVC at 3.1 or 3.2v per cell to prevent capacity loss.

Moral to the ride yesterday, I will be running 12s2p on any ride that will be using more than 3.5ah (70% dod).


Anybody else noticed the same occurrence?

[liveforphysics]

I use the hobbycity rhino packs. I have 32 of the 5Ah packs.

So far, I've had no problems with any of the packs, except the ones I left on my loadbank and fell asleep... lol. My foolishness isn't the fault of the packs though.
Otherwise, they all stay with-in a 0.05V of eachother. I only charge to 4.15v, and only discharge to 3.3v.

No complaints! Pretty damn good bang for the buck.

[Hyena]

I'm interested to hear how you get on with the new turnigy branded lipos. I've been waiting for ages for the zippy flightmax's to come back into stock but it seems they never will now. I too am keen to get my hands on a few 5ah 6S packs, but I don't want to be the guinnea pig to test them!
From what I've read on the hobbycity site they seem to be placed to replace the zippy series - hopefully they are of the same quality. I'm particularly keen to see how they perform in terms of capacity and voltage sag. My current ebay cheapies have really high internal resistance and sagged heaps from the get go, but 100+ cycles later and they sag from 4.2v to 3.2v cell straight off the charge with a 2-3C load (although they still deliver 90% of their rated capacity at this voltage)

According to this thread on their forum they current 15C labelled ones are actually 20-30C. Bargain!
http://www.hobbycity.com/hobbycity/foru ... p?TID=1627

[methods]

The zippy packs are often larger than rated but no matched well as you have noticed.

I.e. You may get a pack that looks like this:
5000mah

5500
5800
6000
5600
5800
6000

I can routinely extract near 6Ah from my 5Ah packs but they go terribly out of balance near LVC.
The trick is to use the BM6 or equ. and stop when the very first cell hits LVC, then when you charge back up they will balance on their own.

But lets be clear - I always get at least the rated value out of the packs, NEVER less.

EDIT: I forgot to mention - always run them in parallel at the cell level! This balances them out much better!

I own
4 Zippy 6S 5000mah 15C packs - 6 months
4 Zippy R 6S 4150mah 20C packs - 1 year
5 Zippy R 6S 4900mah 20C packs - 1 year

The Zippy R's have seen over 1,500 miles of hard, no current limit, 5305 riding. 150A launches all the time. They are showing their age but I have extracted every last penny of value. Early on I would only balance them every 5th charge and I did not use cell level LVC.

The 15C Zippy packs are, oddly, even better than the Zippy R packs. I ran them all the way down to 2.1V /cell once (left the controller on ) and the next day I charged them back up at 2C and it was like nothing ever happened. They are very stiff and hold flat all the way to LVC.

btw: Charge all of them at 2C.

You can not miss with any of these packs. Buy first, ask questions later.

-methods

[Hyena]

That's assuming these new turnigy batteries have the same characteristics as the zippys. It appears they're from a different supplier, made in a different factory. As the above link I posted says, they won't actually be supplying 15C rated cells. They're being sold as a replacement for the zippys, fingers crossed they're actually as good.

[methods]

They will be.
In my opinion we are past the old days of crap Lipo.
Even the lipo that is considered crap (by the RC community) today it gold compared to what the ebikers have been buying (think 2C garbage)

These 15C cells (when run in at least 2P) will be awesome.

I did not realize that they are mislabeled.
I am going to go order 8 right now for another one of my 24S2P packs.

I can do a little happy dance when they get here and you go to get yours but they are all sold out

-methods

[Hyena]

I can do a little happy dance when they get here and you go to get yours but they are all sold out

haha I hope they explode and singe your gonads

I'm torn between buying 4 of these or going with 48v worth of 10ah headway cells. I don't know if I could go back to the bulk and weight of lifepo4 after lipos though

[johnrobholmes]

I have a 3/4 KW of a123 on the way to me and 1 KW of zippy and turnigy here now. I shall take a pic of them next to each other when I can

[Drunkskunk]

I have 8 5 cell % ah packs on mine, 20c rated. I rarely take therm below 3.7V per cell, and they stay balanced fine, although one cell in one pack seems to have swollen slightly, its still staying balanced.
I notoced that running these things at 4 c they stay happy, but at 8c they get warm and sag like no other lipo I've seen before.
I usualy pull 4 amps out of them down to 3.7 volts.

[bearing]

Which brand?
How much sag and in which configuration?
Only 4 amps? 0.8 C?

[Drunkskunk]

My bad, Zippy Flightmax
http://www.hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=8581

4 amps used to nominal, which is only about 60-70% capacity normaly. and thats 4 amps out of the 5 amp packs. I try to avoid dropping below 4 amps per pack to leave a reserve incase of the unexpected.
They preform fine within the 5 amp spec. I have read that they are actualy under rated batteries, but they don't preform well at their actual rated capacity, so they are under rated to a level of consistancy.
I think it's the same philosophy by which the chinese rate their motors. Under rate them to a level were they all can preform at, and appear to be consistant quality with a few people impressed by some that out preform expectations.
I'm not complaining, Thats not a bad thing. They preform exceptionaly well for the price.

[Hyena]

johnrobholmes, have you had a chance to put the new turnigys through their paces yet ?

I was going to just replace my existing 12S2P pack I'm using now but I'm thinking I'll order 6 of the 5S packs and have them wired in 2 banks of 5S2P and 2 banks of 5S1P. From these I can either run them as a 15S2P pack 10ah 63v high speed pack or 10S3P as a longer range 15ah 42v pack

The only hurdle is getting my 24v power supply down to 21v (supposedly 24v +/- 10%, = 21.6v... )

Edit: Just ordered 6x 5S packs, nyer nyer methods

[methods]

I ordered mine first

Only problem is that I ordered 8 6S 5000mah packs and that put me over the limit for EMS Express so I had to ship via the slow boat.

I HATE THE SLOW BOAT !

-methods

[ZapPat]

I ordered mine first

Only problem is that I ordered 8 6S 5000mah packs and that put me over the limit for EMS Express so I had to ship via the slow boat.

I HATE THE SLOW BOAT !

-methods

I'll be looking forward to your results with these new turnigy packs, guys. If that 20C rating rumor turns out true I'll order a bunch myself for sure, since they're 25% cheaper than zippys. And I'm real happy with my zippy Lipo's, and probably won't go back to LiFePO4 until it matures a bit more and cost vs power gets better.

One thing I did notice about the tunigys is that they are a bit longer and weigh a bit more also than equivalent zippy's (based on HC specs) - any idea why?

For shipping from HC I find that it comes to almost the same end cost using either their slow or super fast shipping options. The important thing to notice is that cost per kg actually goes up ove a certain package weight, so it may be best to split the order up into smaller packages. For example, to Canada the optimum package weight is 4kg for express, and 6kg for slower regular air mail. However, no charges or taxes are asked for the express package at the post office, so this very fast option comes out to almost the same end cost per kg! Just use their "postage table" button towards the top of the page to find the best package size were you live.

[johnrobholmes]

The cost per watt hour is also why I chose these type of packs, as well as the spectacular discharge rate compared to cheap prismatic LiFe. I compared the turnigy packs to my zippy ones and they are exactly the same size. The only difference was the shrink and the balance leads were silicon housed wire. I think the silicon sheath will be easier to tear, and I don't care for the extra flexibility.

[Hyena]

I ordered mine first

Only problem is that I ordered 8 6S 5000mah packs and that put me over the limit for EMS Express so I had to ship via the slow boat.

I HATE THE SLOW BOAT !

-methods

Mine shipped out today on the slow boat too. 7-45 days. urrrgh
Australia is closer to China that the US though, so hopefully mine arrives first

On a related lipo note, do you reckon one of these universal laptop chargers set to 21v would do the job for charging my 5S packs ? It's only 3-4 amps so it'd take like 10 hours to recharge 5S6P, but for under $15 delivered I thought it'd do to put a bit of charge back into the batteries while at work to save lugging around my "big" charger.

http://cgi.ebay.com.au/CAR-UNIVERSAL-LA ... 7C294%3A50

[methods]

The beauty of lipo is that you can charge it with anything so long as it is equal to or less than HVC.
Please be very careful to make sure that the open circuit (floating) voltage of that charger is <=21V.
If so, sure it will work.. but it will take forever

I have about 10 of those variable power supplies now and so I have all kinds of chargers:

12S 50.4V 10Ah pack -> 20A 2C 1KW charger (takes about 35 - 45 minutes)
24S 100.8V 10Ah pack -> 13A 1.3C 1.3KW charger (takes about an hour)

I am working on the dual supply monster
24S 100.8V 20Ah pack -> 30A 1.5C 3KW charger.
Will require the special 40A outlets I installed when I built my house

-methods

[Hyena]

sure it will work.. but it will take forever

Yeah that's cool, as I said it's only to partially charge while I'm at work. My commute burns about 5.5ah each way so that little top up for a few hours will enable me to do the return trip on my 60v10ah pack without stressing the batteries (and more importantly, me )

I am working on the dual supply monster
24S 100.8V 20Ah pack -> 30A 1.5C 3KW charger.
Will require the special 40A outlets I installed when I built my house

You know you're clinically mad when you build your house around the charging requirements for your electric bike projects

[Daniel828]

This post made me re-think my battery direction. I currently use 24s1p DeWalt lifepo4 in solderless power tubes. They
are out of buisness, besides it's an expensive route using DeWalt packs and then the work of taking them apart and reconfiguring into the power tubes.
I am thinking of buying some packs from Hobby City.I would probably buy 5 of the 5000mAh 4s1p packs. What charger would I have to buy?
I have a Mastech 30v20a cc-cv power supply that I use to charge my lifepo4 pack. Could I use that?
Thanks
--Dan

[Hyena]

Why 5 x 4S ? Assuming you want to run them all in series for a high speed short range 20S 5ah pack, 4x 5S would be slightly easier to wire up for parallel charging and balancing. If you can afford to drop a few volts easier still would be to run 3 x 6S packs as 18S

If your power supply is adjustable you could use it.
For charging 4S you'll want it set to 16.8v, 5S 21v and 6S 25.2v
You'll need a balancer too, I use this one and I think methods does too.
You can charge through that balancer up to 10 amps but if you're current charger puts out double that you'll have to just connect it to the balance taps of the batteries.

[methods]

I just checked my tracking...
My packs have been parked at the Customs facility in San Francisco since June 13th

I am fix'n to sneak down there tonight, climb in through the window, and get my lipo goodness

-methods

[ZapPat]

The beauty of lipo is that you can charge it with anything so long as it is equal to or less than HVC.
Please be very careful to make sure that the open circuit (floating) voltage of that charger is <=21V.
If so, sure it will work.. but it will take forever

Humm... and just hope that all your cells are very well balanced when not using any cell level monitoring while charging like this?

Personnaly I would only feel "OK" doing this if I set the charger's output float voltage to 4.1V times the number of cells, and not 4.2V per cell (so 20.5V for this example). I actually don't even charge up to 4.2V per cell normally anyways (even when balancing) just to extend the life of my pack. I may loose ~10% usable capacity but the pack's lifetime will be greatly extended.

But you have much more experience using these Lipo's than I do, Methods, so what I say here is just my opinion and a conservative one at that I guess.

I hope your customs thugs let you get your battery fix soon, 'cause I want to know what the internal resistance is for these cells before buying a bunch. JohnRH says they are physicaly identical to the 20C zippys despite HC's specs, so we hope they also perform as well too. My 15C zippy have about 10mohms Ri per cell, so I would hope that the 20C cells are around 7mohms maybe?

[johnrobholmes]

I just found that the pcb is slightly bigger on the turnigy packs. Otherwise the cells are identical. Even the 15c and 20c zippys are the same size, which is kinda strange. Normally higher drain packs will be bigger, unless they are all made to be 20c and the 15c are just the rejects.

[Daniel828]

Why 5 x 4S ? Assuming you want to run them all in series for a high speed short range 20S 5ah pack, 4x 5S would be slightly easier to wire up for parallel charging and balancing. If you can afford to drop a few volts easier still would be to run 3 x 6S packs as 18S

If your power supply is adjustable you could use it.
For charging 4S you'll want it set to 16.8v, 5S 21v and 6S 25.2v
You'll need a balancer too, I use this one and I think methods does too.
You can charge through that balancer up to 10 amps but if you're current charger puts out double that you'll have to just connect it to the balance taps of the batteries.

On the Hobby City site the batteries are identified as 4s1p or 5s1p...etc..I like the 4s1p option because the price seemed to be the best. So if I buy 5 packs it would come out to about 240 bucks plus shipping. Where do they ship from anyway? Would I have to go thru the "customs" hold up issues too?

The Mastech power supply has adjustable Volts and Current too.
Thanks for the input Hyena
--Dan

[methods]

Daniel - Check the site again, it is almost always better to buy the larger pack. Sometimes a 6S sells for only 3$ more than a 5S. If it is not a space/packaging constraint go with 6S packs and higher voltage

Zap - Of course you are right. Sometimes I forget my audience, but for me it is ASSUMED that whenever a Lipo pack is being charged it has a balancer attached. It is also assumed that whenever a big, scary lipo pack is being charged at >2C rates that cell level alarms are hooked up.

To anyone who is considering charging their lipo in "gangster" mode, if you dont do full-pack level balancing then you need to charicterize your pack and lower the HVC accordingly as pat suggested. If your next inclination is to ask how then... Dont bulk charge. Stick with something safer till you have a good feel for lipo.

These work very well.
I just bought another one.

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=9005

Parallel up all your cells at the CELL LEVEL and POWER LEAD LEVEL and balance charge with this.

Charging will now be much safer... BUT... The risk of screwing up while converting from series to parallel just went way up.

-methods