Alright... the moment everybody has been waiting for!! (cliff note below)
I sorted my Tenergy 3500 cells by calculating a resistance value based on what voltage and amperage values I obtained with my digital voltmeter. To make it easy I plugged it all into excel and then sorted the 24 cells into 4 groups by resistance: worst (remember this group has the 2 suspect cells), good, better, and best. Since this was my 2nd side by side pack building experience, I decided to build the 'Good' one first for more pack building practice.
For reference I built my packs using Deans plugs (reused the non-gold one that came from Tenergy; still should be good enough), Deans 12 gage wire, Deans racing pro-solder w/ silver, and Deans pro-bar 3.0. All in the name of reducing as much resistance as possible. Remember resistance is the enemy!
For my test I compared the T3500 to a tired ol GP3300 in side by side config and a generic Epic Motorsports 1500 NiCd. I wasn't planning on using the NiCd at the time so I only re-peaked the Tenergy and GP at 2 amps to a temperature of ~125F. I let these cool down to 80's before I ran them.
The batteries were used with an HPI RS4 Rally, Novak Dually Dual, Orion Double Method R 19T w/ s.diode, 12 gage wiring, deans plugs, and an FDR of 5.5 (street setup). Acceleration testing was done on the residential streets.
I first ran the 1500 NiCd. Had the initial punch that we come to know from NiCd's. Though this pack only lasted ~3-4 minutes. At this gearing this is the acceleration and top end that I'm happy with. End temps were 80's for both battery and motor. I also note the Novak Dually Dual never gets hot ever.
Next up was the GP3300 (these are old matched cells from pro-match btw). This one seemed like time and heat abuse has taken it's toll. While the top speed is the same or slightly slower than the previous NiCd run the acceleration was severely lacking; disappointing. Driving with no response from the throttle trigger is down right disheartening. Top speeds on this run lasted for ~7 min before tapering off. Battery: 120F, Motor: 135 F.
Though it was getting dark, I decided to make what little run I could of the Tenergy to get an initial impression after all my battery building work. I let the motor cool down to 90's (though I really wanted to cool it down some more but there's no more daylight; I threw the chassis in the refrigerator for as long as I could wait). I plugged the Tenergy's in and wow... just WOW!!
Simply amazing! I know it's obvious what new cells could do for you but this has got to be the biggest bang for the buck (~$15 total cost built). The 3500's had more punch and top speed than the NiCd's, possibly even more than my shotgun GP3900's (another test yet to be run and the GP3900's will be receiving the same side by side treatment as well). Now I can look to even more goodness when I assemble the 'better' and 'best' Tenergy cells of my lot.
In my experience it seems like I discovered my own little piece of gold contrary to the very mixed reviews I've been reading all over the internet... i.e. cheap, poor, decent, you get what you pay for. If your competent to know what your doing and what realistic expectations to set then I wouldn't hesitate to try out some Tenergy cells. I would hope Tenergy would rethink their product line up and offer more side by side configurations to help out their public image but we'll see (common at least do it with your flagship Propel's Tenergy!?). Until then it's all word of mouth (or text so to speak). I seriously think these cells are underrated in the public's opinion and I hope my experience shows people how to extract the true potential of these cells. Since I never was able to run them in shotgun configuration I guess it's what other Tenergy users have said in that it's all in the pack construction, a "night and day difference", I'll attest to that!
Cliff notes: Tenergy 3500 cells in side by side configuration is a serious bang for your buck deal!!