Gens Ace 3S 1550 25C vs. Sky Lipo 3S 1600 40C
Let me start by saying this certainly won't be as comprehensive, nor as scientific as many of the other more experienced tester's threads. Rather, this is meant to be a general idea of what kind of real world results you could expect to see with these two packs.
I have several Gens Ace packs ranging from 2S 450's up to 4S 2500's, all 25C, and all are performing extremely well. I needed something in this 3S 1600mah size for a profile jet. Knowing the performance of Gens Ace, and having heard some talk about the Sky packs, I thought I would order both to do a comparison. Seeing that most people who have tested Gens Ace packs have found them to be more in line with other brand's 30C-45C packs, I decided to compare the Gens Ace 25C to the Sky 40C.
Both packs were purchased at the same time from Hobbypartz.com, both roughly $13 and some change, and both have exactly the same number of cycles. The Gens Ace came perfectly balanced at 3.83v per cell. The Sky Lipo came with a slight imbalance, 3.77v 3.82v 3.83v. I independently charged cell 1 up to the rest, and then completed a full charge on the whole pack. Since then the pack has remained well balanced. The Gens Ace weighs 138g while the Sky is only slightly heavier at 144g. The two packs are similar in construction, well assembled, appropriate size wiring for this size pack, flexible silicone wiring on both the main leads and balance leads. The Gens Ace pack is noticeably shorter in length, although a touch thicker than the Sky pack. They both came with the typical red 4mm bullet connectors, but I changed them out to Ultra type connectors. The IR's were nearly identical for the two packs, measured using my iCharger 208B at 70* F, packs fully charged, Gens Ace 4 5 5=14 and the Sky was 4 4 5=13.
I did roughly 3 low C discharge cycles followed by 2C charges prior to the following 10C and 20C discharges below. The 10C discharge I did down to 10% capacity remaining, the 20C discharge I stopped it at 20% remaining capacity. As you'll see in the graphs, they both performed nearly identical in both test, and both did very well in my opinion. Considering that the Gens Ace is 25C and the Sky Lipo is 40C, I'd have to give the win to Gens Ace, but I'd feel comfortable recommending either pack, although I would personally not choose to buy a Sky pack that is less than 40C. Looking at some of the other graphs in the Battery Graph Vault, I'd concur with what most of the other test packs have shown, that Gens Ace 25C packs are conservatively rated, or maybe more accurately rated, and perform as well as most other brands 30C+ rated packs. It's also nice to see that the Sky Lipo packs are showing promise, at least in the high C rated packs. How they both hold up over time remains to be seen.