WARNING: Turnigy batteries

[Dillzio]

Just though I'd warn you guys about buying the Turnigy batteries from hobbyking. I got some 2200mah 20C batteries for my cub, and have been very disappointed with them.

This battery is completely inferior to the Zippy Flighmax batteries, I bought 4 of them and found they all had one dodgy cell that would go flat before the others, despite how well balanced the battery was to start off with. Once my plane hits voltage cut off, I'd find one cell on 3v, and the other cells at 3.7-3.8v. The dodgy cell only gets worse over time too due to being forced under 3 volts while under load.
NEVER AGAIN!

[leisureshoot]

Interesting. I wonder if you got a bad batch? It is pretty well documented that their QC is less than acceptable. If you read almost any product reviews on HK, you see a lot of "the ______ broke after 2 uses!" or "works ok, but the fan doesn't come on unless you tap it". A significant portion of the R/C kingdom seems to run on Turnigy. Goes to show, $$ is king. But, spending less money can be more expensive when you have to purchase 2 times just to get an acceptable product.

[killioughtta]

@dill

That's good to know from someone like you (who flies a similar model). I own only one Turnigy pack, a 3s 1300 mAh 30C. It has like 3 or 4 cycles on it so I can't judge it yet. I have another cheap pack from a lesser known name (can't even remember) that has like 15-20 cycles and it's still performing well. My oldest Zippy (2200, 3s,20C) has like 40 cycles and it was going strong until the white wire on the balance plug broke from the battery. Now I have to try to repair it or get rid of it. My newest Zippy (Same as older one) I received along the Turnigy and has about 3-5 cycles, too. I love the Turnigy because it gives me a strong discharge but and balances right but I'm weary of it and will have to wait-and-see. Thanks.

leisureshoot
I like HK for the prices and think it's worth a trade for QC. I can still buy 4 or 5 Turnigy/Zippy batteries before a Thunder Power pack. That's impressive. No doubt about it; the Zippys have been tried and tested to be rugged little batteries. Like I say above, the Turnigys will have to wait for my real opinion based on personal experience. P.S. Welcome to RCGroups

[iflyforfun]

I have 4 Turnigy 1300mah 15C batteries that if I were to guess I would say thy have between 20 and 30 cycles. I also HAD 8 Turnigy 2200mah 20C batteries that have somewhere between 10 and 15 cycles. I said HAD because one cell in one of those decided to go on vacation. All in all I have had NO problems with the batteries other than the obvious over rating.
I was having a problem with my 2200's getting hot and a couple of months a go I learned from Flydiver the importance of the 80% rule.
If you believe the label the 2200mah 20C should be able to deliver 44 amps. But they getting HOT pulling 31 amps.
Take 20% off each number and then do the math.
2200 - 20% = 1760 mah
20C. - 20% = 16C
16 x 1.76. = 28 amps

After learning about the 80 % rule I re-propped from the 11 x 5.5 pulling 31.8 amps to a 10 x 5 prop pulling 25amps and now after a 10 to 12 minute flight my Turnigy packs are comming down just a little warm. The big difference is the thrust, I went from over 50 oz's thrust to 39 oz's thrust.

I am very disappointed in the obvious over rating. But when paying about $10.00 bucks a pack I can accept it.

I decided and bought 4 Flightmax 3000mah batteries for my Multiplex Fun Cub. I still have to fly a little more to get a baseline and feeling there performance but so far I very happy. I'm flying with the Turnigy 35-42 and a 12 x 6 prop pulling 37 amps. The batteries are comming down almost cold. very little temp rise. The Flightmax label says 3000mah at 20C, that should give me 60 amps, but because of the 80 % rule only 38 amps. I picked my whole setup based on those batteries and the 80% rule. I can't prop bigger to test a higher amperage because my ESC is only a 40amp, but I feel(guessing) that the flightmax batteries would have the same problem as the Turnigy's if I were to try and pull 45 or 50 amps.

I have not had bad luck as Dill has experienced(yet) but I thought that someone might find my info helpful.

Ifly

[iflyforfun]

On the subject of batteries, what is a good battery? Or great battery?
I've learned that Castle Creations makes a great line of ESC's that are tested and underrated. Great quality product. But what about batteries. Are there any manufactures out there creating batteries that meet or exceed the Mah or discharge rate without getting hot.

flydiver, do you know if an actual "Not to exceed" temperature exist for lipo's. We all talk about cool,warm,a little warm,to warm, a little hot and so on and so on....Im sure 10 people would give 10 different answers to the feeling of warm. I was wondering from a technical standpoint how much heat does it take to become "not good". I have been reading about data loggers and FPV systems that collect data including battery temperature. I'm not interested in any of these systems, I would like to measure the temperature of a Pack after flight and based on a number know if I'm asking to much from it.

Thanks
Ifly

[flydiver]

The accepted max temp has been 140*F.
But, just like max C-ratings have been inflated some of the sellers are now rating them to 150*F.
That falls into the category of 'prove it before I'll believe it'.
Have I sent you this link?

C rating hype and dog eat dog lipo marketing
www.rcgroups.com/forums/showthread.php?t=1293027

You also might like this. It's over a year old in a fast paced market so the concept may be more valuable than the particulars:
WHAT LIPO - Independent Lipo Tests
www.rcgroups.com/forums/showthread.php?t=1087725#post12795502

I wish I could state categorically what a great battery was but it's a moving target. I'm a conservative user and haven't bought a new lipo in over a year. I figured out how to take care of them and keep 'em going. What I do have is a rag tag collection anyway mostly gathered while I was still learning. It is amazing how much prices have come down in 3 years.

I do think that once your planes get over ~3# you might seriously consider looking at the A123 packs. I use some of the smaller 1100mA A123 for my Funjet but the weight/power ratio is not favorable for small park fliers. It is way better than NiMh though.

Edit-if you really want to follow up on best lipos I suggest you spend some time in the Heli forums. Those guys thrash their lipos something nasty. If it doesn't hold up they find out. Spyder had a good summer. Don't know if they are still a hot item.

[iflyforfun]

Thanks Fly, I will check out those links you sent me right now. Can't remember if you sent them before. I've been listening to old shows(ATTF), reading and learning so much that I can't keep track of the info anymore. ;D
Remember the show where they talked about the 10 worst mistakes? In that show they mentioned that they had A whole show dedicated to ESC and BEC's sometime in the past. I think they said Lucian was on for that show. I've been looking for that show but can't find it. I shot off an e-mail to them asking if they could help me with the show number. I figure another 6 months and I will have listened to all the shows back to 2007. ;D
140 F , wow, in my mind I would think 140F would feel very hot. But I'm not sure. I will run a pack and see what hot actually feels like to me. It could be 180F I have no reference point. I have a very accurate Fluke digital temp meter that I can tape to a battery. I may even cut open a battery and get the probe down between the cells. In the future I want to be able to say" I run my xyz setup at WOT for most of a 10 minute flight and my packs are coming down at xx temperature. That to me would be a very accurate portrayal of someones setup and takes more guessing out of the picture.

Thanks
Ifly

[flydiver]

Temp reference - most hot water heaters are set a 120 now. That's about as hot as you can stand. At 130 you can't hold a finger on long. At 140 you won't even try.

Have you found the link of the side of ATTF that some listener has done to catalog the PSC? You might be able to find it in there.

I have an IR thermometer but it's a spot reader. I bench test and check temps.If they pass that I do a 30 sec WOT flight with quick landing and re-check. Then a minute, then 2 minutes. If it passes that it should be OK unless I have rotten airflow cooling to some component.

As you might figure you see pilots seriously overprop all the time. If it doesn't burn up in 30 seconds they figure it's fine. I let a buddy cook one of his motors because he just wouldn't listen to me. I could see the windings on his motor turning dark and wisps of smoke coming off it after a flight. He's paid more attention since then.