by The JANG
Good matched batteries, unfortunately, don't come a dime a dozen. Generally, in fact, they're in the range of 750 to 1,000 dimes, sans assembly! When I was on the market for some reliable replacements for my deteriorating Stock Metal Hydrides in early '03, a fellow racer turned me on to Team Integy, wherefrom he claimed to have procured his race packs for under sixty bucks. I saw his buggy on the track, and it was fast, yet his best lap times came towards the end of the race. These cells had punch and stamina. Seeing was believing, and it wasn't long before I picked up some of these bargain packs for myself.
The Numbers Game
Alright, first off, here are the figures printed on one of the packs I received:
| Avg. V: | 1.21V |
| Runtime: | 607 sec. |
| Cutoff: | 0.90V |
| Charge: | 5.0A |
| Discharge: | 20A |
If you're not familiar with the game, battery manufacturers play a lot of tricks with their numbers to artificially inflate them and make you, the customer, go "ooh" and "ahh" and "here's my credit card." The runtime figure (607 seconds in this case) is a count of the number of seconds it takes a fully charged cell in a 6-cell bank to go from a full charge down to the cutoff point (0.90V) at the stated discharge rate (20A). The higher the cutoff point, the lower the runtime figure and the higher the average voltage. Fortunately, 0.90V is an industry standard, so there's nothing funky there. However, race packs are generally discharged at 30A, and this pack was done at 20A. This inflates the runtime figures on these Integy cells by about 33%. The average voltage figure is also fudged. On the detail page of one of these packs on Integy's site, they casually note a "375s average voltage calculation point." Translation? The average voltage figure is not an average voltage figure. It is, in fact, a measure of the voltage of the cell under load after being discharged for 375 seconds (at 20A).
Now, all of that said, let's put these numbers into perspective. Adjusted, the runtime would be just over 400 seconds at a 30A discharge rate. That's on par with Trinity's $79.99 "Team" sets on Tower Hobbies. The 375 second "voltage calculation point" translates to 6 1/4 minutes. A pack of cells that are still over 1.2V apiece after 6 1/4 minutes of running with the equivalent amperage draw of a stock or mild mod motor, that's not too shabby.
One thing that truly impressed me about these packs, though, is that each was composed of identically-matched cells; the runtime & voltage figures were the same across each set of 6. I don't believe this was part of "the game," either. Each of the cells was marked by hand with an ultra-fine Sharpie, apparently by the person taking them off of the matching machines, in addition to the machine-printed labels. This is the first time I've seen commercially-available packs for under $100 that were this well matched.
The Big Test
All of this talk about numbers may be good stuff, but there comes a point where theory gets boring and some down & dirty experimentation is called for!
As of this writing, I had used my two Integy packs on two separate occasions, both in my stock-powered Ultimate Rustler. The first time was a long open practice session on an off-day at the track. I charged the packs on my Novak Millennium at 5.5A with a 2.7mV/cell peak delta (to get this on my older-model charger, I selected 4mV/cell, the lowest setting, but set the cell count to 4). I watched the charger's LCD screen intently as each pack approached its peak, and the cutoff timing was perfect. No first-charge false peaks or overcharges here. Both packs took over 3,750 mAh of charge and peaked at over 9.77V. By comparison, when new, my first-generation Sanyo 3000's were peaking at 9.36V and taking about 3,200 mAh of charge. So far so very good.
On the track, I got as much power out of my truck as I could ask for. Better still, I didn't start noticing any reduction in speed for over 10 minutes. After about 14 minutes of continuous laps, I could really see that I was dumping, though I surely had another couple minutes or so of emergency runtime. I pulled the truck over to feel how the batteries were doing, and they were just gently warm -- cooler than they are when they come off the charger. The second pack behaved eactly the same way. This is a good thing.
My second use of these batteries was the following day, at an actual race event. For several reasons, mod & stock and 2WD and 4WD electric trucks & buggies were combined into a single group. In the first heat, I placed 2nd overall, beating four mod and three stock vehicles, bested by a 10x2-powered XXX-T which lapped me once. Now, track performance is determined by a huge number of factors, but one thing was certain -- my batteries were not holding me back one bit!
Shopping Around
One really great thing about Integy is that they offer a dizzying array of cell sets, from 2000's to 3300's. Among their 3300's alone, you can chose from GP or Sanyo cells, and go from $39.99 to $79.99 per set, depending upon stats. If you're a stock racer, you can get packs that favor voltage over runtime. Run mod? Get the opposite. Or get anything in between; the choice is yours to make, right on their site. I chose Sanyo brand cells for their historical stability, predictability, and long-term durability, and went for medium-high voltage and high runtime.
Keep in mind that most of Integy's battery offerings are unassembled packs -- they send you a box of loose cells. The cells are individually shrink-wrapped, but you need to buy battery bars and connectors and use a soldering iron to put them all together. A battery-building jig is also a good investment, in my humble opinion. All of these accessories are also available at Integy's online store.
Final Analysis
I really would have preferred more standardized numbers on the labels, using a 30A discharge rate and reporting true average voltage figures. The cells have good stats and Integy should show them off in a completely honest and forthright fashion, but, alas, "the game" goes on. Nonetheless, after actually using these packs, I'm simply in awe. The performance to price ratio is truly excellent, and I would gladly recommend a visit to http://www.Integy.com/ to any racer who wants to score some great cells without breaking the bank.
