Zippy Compact 35C cells overrated!

miuan

10 kW
Joined
Nov 26, 2009
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Slovakia
Bought 7 of these (10S 4.5Ah) to make a 20S 13.5Ah pack and have one spare brick. The price was $60 a piece in NL Warehouse on flash sale, a real bargain for 35C cells. The box was damaged but cells arrived intact and well balanced, all within 3.82~3.85V, ready for paralleling.

As far as performance goes, these are NO WAY 35C cells. Tested them today and they sag violently given their rating. On a 55-60A controller the sag was as much as 4 volts, even outperformed by my 3yo 20C Turnigy hardcases!!! Don't get me wrong, these are still good batteries, but they're more like 10-15C, far from 35C. I really wanted to like them and was expecting close to 1-2V sag. Still, for me this is no problem since I never exceed 5C load, but for real high power applications, these would be a poor choice. Hope this helps other make the right decision.
 
miuan said:
Bought 7 of these to make a 20S 13.5Ah pack and have one spare brick.
i'm still trying to figure out what configuration this could be? what are the single bricks? 10s 4500mah x 6 in a 2s3p configuration?
a 3p configuration should really not sag that much at 60a.
 
miuan said:
izeman said:
10s 4500mah x 6 in a 2s3p configuration?
a 3p configuration should really not sag that much at 60a.

Yes, sorry, I've edited the OP accordingly.

maybe the zippy compact uses some different chemistry? i ordered (the not really new) 6a 5000mah 25-35c cells to match my other packs. i'm planning to run a 12s4p setup and around 40a max, so i hope not to see a lot of sag.
 
Lotta sag for 13 ah of 35c. Might be worth looking at them individually, for one with really high resistance.

Could be you just need to sort out the bad one, which is SOP for RC lico anyway.
 
I would agree with the OP.
I run 15 25C 3.7AH bricks in a 18S5P setup in my Fighter. I see 4-5V sag under load and that's only after ~50 cycles. They are definitely not what is advertised.

This setup should be giving me around 1.2KW also, however I hit 3.5V per cell at around 900Wh used.

Disappointing to say the least.

Cheers
 
It does sound like what you'd expect from cheap 20c zippies, not 35c.

90% of the zippies I bought sagged a lot, and are 20c. Less than 15 ah size performs for shit. A few 30c zippies I bought were at least better. But still not up to what the 30c turnigy I bought years ago could do.

I think there remains some big variation in cheap lico performance from batch to batch. But there is a noticeable trend in the reports, that zippy sags more than turnigy. Often, not that big a difference in price, unless you get the zippies on a dumping them sale.
 
Personally I can't wait until my zippy compact pack is fubar so I can get Turnigy 65 through 130 c discharge pack. It seems you really do get what you pay for.
 
i measured my 1 year old 25c zippys and got ir between 10-14mohm from my icharger 206. i don't know how exact those values are.
now i feel stupid that i wanted to stick to the same battery i already have, and didn't spent $100 more for a higher c-rating. on the other hand i thought that 1500w (maybe 2000w max @12s = 45a) would see no real sag for a 4p setup of 20ah. it's 10a for a single battery or 2c.
what do you think? would a more expensive battery perform reasonably better?
i also googled a lot the last hours and found that the zippys may not be that bad when new, but start to raise their IR after some discharges. unfortunately i didn't have a chance to measure those batteries when i got them new, so no way to compare.
what is your expierence?

ps: to OP: i hope it's not seen as high jacking the thread if ask those questions in your thread
 
Izeman, my commuter bike uses zippys 30c 8 Ah 24s and my sag is acceptable because I'm only using 5000w MAX and only for short bursts. My cromotor is a different story. Can use up to 12.7 kw and that is when I get major sag.
 
I would rate the Turnigy above the zippys. If you compare actual dimensions, you get a a reduction in size, hence the name "compact". Your giving up something for that reduction. Saggy packs under load :roll:
 
I been casually reading on this forum virtually everyday for around 1.5 years and there has always been a constant view of zippy batteries from those that have played with a fair amount of lipo and that is that Zippy lipo constantly over rate there caperbilities and Turnigy are a lot more accurate as in what it says is what your get.

Would be good if some one made a video on YouTube to demonstrate the crappyness of Zippy lipo so that it becomes a bit more well known.
Who knows maybe with enough boycotting of zippy they will be forced to lower their prices and be honest.
 
izeman said:
which cells? zippy, turnigy, compact, nano?
These; http://www.hobbyking.com/hobbyking/store/__21358__ZIPPY_Compact_3700mAh_6S_25C_Lipo_Pack.html
21358.jpg


Like this; http://endless-sphere.com/forums/viewtopic.php?f=6&t=23996&start=3900
P1060312.jpg


Although I've since added an extra 3 packs for a total of 15 in parallel.

Cheers
 
izeman said:
ps: to OP: i hope it's not seen as high jacking the thread if ask those questions in your thread

No issue there mate... discussion is welcome, so it can reveal others' experience with Compact Zippies. In my case, I really don't mind the lower C rate all that much. For others it may suck badly.
 
i also considered buying the compacts but then decided against them as there was no added value.
will be interesting to see if this a problem with the compact one only, or if it's maybe a bigger problem then with the regular ones.
they clearly overrate their packs. question is: is the extra reduced sag worth the extra money.
if i take 12mohm for a single cell this adds up to 36mohm for a 12s4p pack made of 6s bricks. this would give 1.5v sag for a 44c nominal pack @50a. i can live with that i guess.
 
The main issue I have with these packs is the miss representation of the capacity. I wouldn't mind so much if it was just the C rate, but I'm only seeing ~80% capacity from new on these packs. You could probably squeeze 85-90% out if you drained to <3V per cell, but it's still not acceptable IMO.

Based on my experience with these, and my constant desire to go further and further on my E-bike I've decided my next pack will be a monster 2KW+ 18650 pack. :mrgreen:

Cheers
 
Only takes one cell in a large assembly to drastically lower capacity. Did you run them long enough to break em in, then sort them?

No surprise that compact type would be tighter on real world capacity. They don't get smaller lithium to make it. They make it smaller. I recall seeing test stickers on turnigy cells that said 5.2 ah. Since zippies are smaller in physical size, I never was surprised to see slightly less real world capacity from mine, compared to the turnigy I had.

Izeman, the use you have in mind should not sag more than you can tolerate. I pull 2000w from 15 ah of regular (not compact) shitty 20c zippies with no big problem. Only about 2v of sag when pulling 2000w. 1v when pulling much less. It's worse if I only use the 10 ah pack for sure. This is on a set of packs I bought last spring. It's in two sections, so I can carry just 5 ah for the short dirt rides I do daily. I only pull 1000w in the dirt, since my dog only runs 7 mph.

I don't try to get 15 ah out of the whole pack, but I'm pretty dang sure they can't do it unless I ride at 1000w or less. Last time I really did a 100% discharge at slower speeds, I vaguely recall I only got about 13.5 ah. But I don't usually ride it down to below 3.5v per cell. 14 ah is stopping someplace between 3.6 and 3.5v.

There is still some capacity there at the very bottom, but I don't consider it real world usable capacity. Even my previous 30c turnigy pack never really put out 10 ah, ( riding at 2000-3000w) unless I drove em all the way to 3v. I just operated as though that was a 9 ah pack. If I discharged them deep, I could squeeze out 9.5 ah when they were new.
 
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