HK turnigy vs batteryspace UL tested lipo cells

[silviasol]

I made this pack I kept in my backpack as a backup in case I ran out of power. I put 6s of the turnigy 5ah $25 4s packs I had spare from my new pack in parallel with 6s of batteryspace UL tested 4ah cells(from a $500 7s 8ah goped pack). The turnigy cells are now 10 months old and have maybe 15 cycles, the batteryspace cells have 50, maybe 75 cycles as I used it for 4 months before I upgraded my battery. The turnigy are slightly puffed, the batteryspace are flat as a new. Clearly much better quality! Of course the cost of one cell is equal to almost 4 of the turnigy's though.

http://www.batteryspace.com/high-power-polymer-li-ion-cell-3-7v-4000-mah-6050140-10c-14-8wh-40a-rate---ul-listed-un38-3-passed-ndgr.aspx

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=18631&aff=421628

 

[dnmun]

once i got my pouches back under compression i did not have the puffing problem. but the pack is now buried inside it's wooden box too so i cannot see as easily but i think if you had kept those under compression you would not see that much puff. can you accurately measure capacity and compare them? from full charge to 3V?

 

[wesnewell]

Hmmm... I've been running my 24s2p 20c turnigy pack for over 2 years and 8K miles at 30 cents per wh. I think I'll stick with them rather than paying $1.35 per wh for some 10C stuff that won't last any longer according to their own spec sheet. My pack (888wh) cost about $275. Using their lipo it would be about $1200. Yeah, I'll jump right on that. :lol:

 

[dogman dan]

Well, you should have had at least some tape on those turnigy. Maybe you did, or just cut the shrink off today. But it's not exactly a news flash that HK cells will puff slightly by the time they are a year old.

If you store them charged, they will definitely puff just a little. I now store charged at most 24 hours, like charge Friday night so I'm ready to ride sat morning. At a year and a half, I have zero puffed cells on a 48v 10 ah pack.

 

[silviasol]

Well, you should have had at least some tape on those turnigy. Maybe you did, or just cut the shrink off today. But it's not exactly a news flash that HK cells will puff slightly by the time they are a year old.

If you store them charged, they will definitely puff just a little. I now store charged at most 24 hours, like charge Friday night so I'm ready to ride sat morning. At a year and a half, I have zero puffed cells on a 48v 10 ah pack.

One side has the stock tape on it, it is just as puffed as the other. They were both wrapped in kaptan tape. The pack was fully charged over the winter, but that did not affect the batteryspace just the turnigy.

once i got my pouches back under compression i did not have the puffing problem. but the pack is now buried inside it's wooden box too so i cannot see as easily but i think if you had kept those under compression you would not see that much puff. can you accurately measure capacity and compare them? from full charge to 3V?

When I get a gps I am going to run each to 3v trying to hold them at 3c amp draw to get an idea of difference, I will update this thread.

 

[dnmun]

you should never leave the lipo fully charged for long periods. 3.7-3.9 is ok but full charge is hard on cycle life. to determine capacity it is easiest to use a dummy load and discharge the pack at .3-.4C through a wattmeter into the heater. then you can get reliable numbers and by working on the battery on the bench to do the test you can monitor all the cell voltages at the same time so you can see which have the most capacity and which has the least and hits the LVC first. but you have to be sure to fully charge each cell to accurately determine the capacity. charging to 4.12V instead of 4.2V leaves 8% of the capacity uncharged.

 

[dogman dan]

The catch 22 of course, is how do you carry it around all the time as an emergency reserve pack, and not store it charged for a long time? One option might be to carry it charged to just 4v. It should help some, if the less capacity when you do need it won't screw you too bad.

If you don't ride in the winter, then you'd discharge it some for winter storage.

Next summer, I'll be able to see how big a difference it makes, as 48v 15 ah goes into it's third summer. So far, its obviously been less mild puffing, at a year and a half. This set has not been stored charged for longer than overnight once in a while. Now the routine is morning charge, ride, then store at 3.8v or less.

 

[Grinhill]

I can offer some more anecdotal evidence about Turnigys. I've had plenty of Turnigy packs that have sat on my shelf at 3.85v for two or three years, then have provided a few hundred cycles of service.

I find the Zippy packs are just as good also.

The packs on my wife's commuter, which only does shallow cycles (4.15 to 3.85v) has done around three years and 500 semi-cycles.

No complaints about them from me.

 

[ARod1993]

Speaking of Turnigy cells, do people have a sense of how many cycles you can get out of them if you run them at 20-40% of their advertised C rate? I ask because I'm interested in assembling a fairly big pack (40-50Ah) and having burst current top out somewhere around 250A phase, maybe 150-200A battery. That would give me 3-5C discharge, and somewhere between sub-C and 1C charge depending on what kind of outlets I have available. Given Hobbyking's reputation for creative product advertising, I figure I'd want something in the range of 10-20C rated continuous discharge to make sure they can actually do 3-5C without sagging badly; I'm wondering how far I'd want to over-spec the batteries if I wanted to get 1000 or so charge cycles out of them before they drop below 75-80% capacity.

 

[Ykick]

As far as Lipoly’s concerned they usually deliver about 1/2 label C rate before sagging more than what I consider comfortable. 2-3C is very realistic with Turnigy 5Ah 20C cells I’ve used over the years.

However, in addition to aging, cold temps will definitely mess with C rates and introduce considerable sag. Below freezing it gets bad and if unable to start out with room temp cells, below 15F old or new they’re basically unusable.

1000 full charge cycles will be hard to achieve IMO. I’ve gotten close to 1k shallow cycles over 3-4 years but that’s when regularly cycling only about 50% capacity. By that point they're very saggy....

Speaking of Turnigy cells, do people have a sense of how many cycles you can get out of them if you run them at 20-40% of their advertised C rate? I ask because I'm interested in assembling a fairly big pack (40-50Ah) and having burst current top out somewhere around 250A phase, maybe 150-200A battery. That would give me 3-5C discharge, and somewhere between sub-C and 1C charge depending on what kind of outlets I have available. Given Hobbyking's reputation for creative product advertising, I figure I'd want something in the range of 10-20C rated continuous discharge to make sure they can actually do 3-5C without sagging badly; I'm wondering how far I'd want to over-spec the batteries if I wanted to get 1000 or so charge cycles out of them before they drop below 75-80% capacity.

 

[silviasol]

you should never leave the lipo fully charged for long periods. 3.7-3.9 is ok but full charge is hard on cycle life. to determine capacity it is easiest to use a dummy load and discharge the pack at .3-.4C through a wattmeter into the heater. then you can get reliable numbers and by working on the battery on the bench to do the test you can monitor all the cell voltages at the same time so you can see which have the most capacity and which has the least and hits the LVC first. but you have to be sure to fully charge each cell to accurately determine the capacity. charging to 4.12V instead of 4.2V leaves 8% of the capacity uncharged.

I could hook them to my b6ac and do a 1amp drain. Or if you have any advice using my cell log alarm and some kind of device to drain them.

 

[silviasol]

I left these batteries fully charged since I did this post. Yesterday I find the turnigy's even more puffed and one of the middle one's popped! The batteryspace UL still absolutely no puffing, flat as a board. You get what you pay for I guess.

I mean my god if you pack is already puffed and let the battery sit for 2 freaking months at full charge and one cell will pop from puffing! OMFG!!

 

[dogman dan]

Yep, you won the bad cell lottery. Now you see why we buy 10 packs if we want 9 good ones. A bad pack, with contaminants can puff while being shipped, or puff on the first cycle.

Keeping them compressed will help with the slight puffing that happens, but a truly bad pack will puff no matter what.

 

[silviasol]

A batteryspace cell has died! Luckily I saw one cell sitting at 2.5v after a short ride. One has puffed and failed! But the others still perfectly flat. Luckily I have an extra cell to replace it.

 

[wesnewell]

And I just started my 4th year with my Turnigy 10ah 20C 24s pack. I don't keep track of cycles, but I've got over 11K miles on it now. I'd guess maybe 300 cycles on it. I had planned on replacing it every 2 years, but now I'm thinking every 4 years or longer.