One can not do the whole "Thunder Power experience" without trying their bread and butter product, their lipos. Well my two 550e Turnigy flight packs were getting very tired, so I decided it was time to leave the cheap packs and try out the best, or at least the best in my terms. This best turned out to be the new G6 line 45C 2700mAh 6s pack. They are the middle of the road G6 pack but cost less than the previous G4 45C packs.
First impressionsThe first thing I noticed about the packs was that they were an odd shape for a 6s 2600ish pack. I have used the stubby Hyperion VX packs and the more typical long, thin packs like those from Turnigy and Voltz. I have to say I prefer the long variety but I was not put off by the shape of the TP packs. I was however worried about whether they would fit in the 550e. No problem there, as it turns out they fit fine but just barely.
The weight of the packs is a little on the heavy side compared to my other packs (key words there being "my other packs"). I usually run lower performance, lighter packs, and so the bigger, heavier TPs just surprised me a little bit. Each weighed in at 442g. By comparison my Turnigy Nano-Tech 2650mAh 25C packs and my Voltz 2600mAh 35C packs weigh 388g each. That makes for a total flight pack weight increase of 108g or almost a 1/4 pound. Of course this extra weight will come with the benefit of using slightly larger capacity, 45C rated packs that should easily make up for the extra weight with solid performance, at least that is what I expect.
The main leads on the pack are 12awg silicone sheathed noodle wire. I believe that 12awg is the perfect wire size for these packs and I commend TP for not following some of the other assembles in using vastly over-sized wire that is not only heavy and expensive, but also a total pain to deal with. The wire itself is different than any silicone noodle wire I have used. The silicone sheathing is very tough and requires much more effort to strip than most other silicone sheathed wire I have come across. I personally like the tougher sheathing, so to me this is a plus.
Now to one of my few complaints concerning all TP packs, the use of TP style balance connectors. Most of the industry has standardized on JST-XH plugs and nearly all chargers ship with the ability to connect to them, including the TP820CD. In addition to the choice of connector, the wires leading to the connectors are very stiff and too short. In fact they are short enough that I had a hard time getting them connected to the balance board that comes with the TP820CD! Maybe they are meant to be used with TP balance lead extensions. If so, then the charger or packs should have come with them. I will also note that the first time I went to unplug the larger 6-pin connector on each pack, the little catch broke off. I will agree that JST-XH connectors are also not perfect but at least they are the standard, and so I would really like to see TP adopt them. In the end the use of TP style connectors is not a deal breaker by any means but it is a minor annoyance and an inconvenience for most hobbyists.
Starting off on the nice foot
These are the most expensive packs I have ever owned and so I plan to do my best to keep them as happy as I can, for as long as I can. This started with a few charges and discharges on the TP820CD. Normally I don't recommend doing this but I needed to test the charger and this seemed like a great way to do it. I then flew them semi-nicely for the first 5 flights, only discharging them to about 50%. I did charge them at 2C from the start and plan to do so for the life of the packs. On the 6th flight I flew a specific set of moves, call it a test flight, and logged it on my CC Ice esc. As the packs age I plan to do additional "test" flights and compare.
Additional data and thoughts
From here on out this review will turn into an event log of sorts. As I learn new things I will post them up. I will be directly comparing these packs to a pair of Voltz 35C 2600mAh packs I purchased recently.
Apr 24th, 2011 - Cycle #14. After the packs charged and cooled, I checked the IR and all cells show 1mohm except for one showing 2mohms. The packs are doing great. They feel just a touch stronger than the Voltz packs and are noticeably stronger than the aged Nano-Techs. For example when doing tic-tocs with the NTs on-board, I can hear the power system load and unload each time. When I do the same moves on the TPs, the power system sounds constant. In fact it is eerily constant. The logs show the TP packs normally only dip to about 42.5V under load vs. 41.5V for the Voltz and 39.5V for the NTs.
Apr 20th, 2011 - Cycle #6 and baseline log. The flight went like this.
Take off and level out. Full collective climb for 3-4sec. Tail slide into full collective flip and push out (first big spike). Cruise around and land on runway, full on drag race launch (second big spike). Do constant stationary full right aileron rolls until timer goes off. Full collective climb for 3-4sec. Land.
Apr 15th, 2011 - Soldered on connectors and checked voltages and IR before first charge. All cells are at 3.82V-3.83V and IR was 4mohms across the board says the TP820CD.