FEATURES
2S2P Configuration • The Peak 4800 cells are arranged two in a series, parallel to each other. Basically there are a total of four cells with two cells per individual pack. The parallel arrangement allows cell capacity to increase without a change in voltage. This setup allows for a small number of cells to hold a large amount of energy.

Zero Loss Connectors • The pack's wires are not soldered to the cells themselves, but instead plug into the case of the pack using zero loss connectors. This may seem less efficient and conductive than a solder connection, but these zero loss connectors are super conductive with minuscule resistance. Strangely, attached to the Zero Loss connectors was a high loss Tamiya-style plug, which we recommend removing in favor a high quality plug. So don't be fooled, the connectors are excellent. If the wires weren't removable, you'd essentially never be able to change them, because you should never disassemble a LiPo pack. The lithium cells can be volatile.

Shock Resistant Case • Peak's LiPo batteries are first enclosed in an aluminum envelope, and are then encased in a rigid plastic structure. Because of the volatile nature of the lithium in the cells, it is important that the pack be nearly indestructible, especially considering the extra power that LiPo cells will provide. In the infancy of the LiPo movement, cells were often not encased so carefully. There have been horror stories in model helicopter circles involving crashing with a LiPo pack, only to have the combustible lithium cells do just that--combust! The plastic case on Peak's pack will ensure your and your car's safety.

THE TEST
I'll be the first to admit that it's not exactly fair to compare LiPo cells to their NiMH counterparts, because it's essentially apples and oranges. But the one thing that we are all concerned with is results. Let's see if Peak's pack accomplishes what it claims: lighter weight, lower operating and charging temperatures, more punch, more speed, and longer run time.

Weight
Peak Racing LiPo: 251g
Fusion NiMH: 392g
Results: This is pretty simple; Peak's LiPo pack is 36% lighter than the NiMH. There's no refuting this. But there is, however, one important matter to consider. Just because the pack is lighter, it doesn't necessarily mean that it is better. Most vehicles are designed with the weight of the battery pack in mind. By dramatically reducing weight, you may upset the balance of your car's chassis. This holds especially true for touring cars, where battery placement and location are extremely important. You'll need to experiment with the LiPo pack and figure out if you'll need to add weight or place the battery in a different location.

Run Time (Average)
Peak Racing LiPo: 26 minutes
Fusion NiMH: 11 minutes
Results: For the results of this test, it is important to realize that although the LiPo pack provides a much longer run time, it's not recommended to run your vehicle for this long. Most electric motors are designed to be run for 5-6 minutes. Every second longer results in greater heat buildup and excess wear and tear. This doesn't mean that you can't enjoy the extra battery life that a LiPo will provide, but you have to closely monitor your motor, watching for excess heat and wear. If you run a brushless system you can worry less about running too long, because there is much less friction to build heat. Also, you are never supposed to run a LiPo below 2.7v per cell, so when your car begins to slow down, you need to immediately pull it off the track. The stated run times reflect stopping the run at the first sign of power loss.

Temperature
Peak Racing LiPo
Charging Temp (max): 81.2° F
Running Temp (max): 93.3° F

Fusion NiMH
Charging Temp (max): 107.1° F
Running Temp (max): 109.8° F

Results: As they claim, the LiPo pack does in fact charge and operate at a lower temperature. This is important because if the pack heats up during operation, this means that it is losing energy. The heat has to come from somewhere, and the NiMH pack is using your valuable run time and punch to make heat instead of power. The LiPo cells retain their energy very well, which is why a fully charged pack will barely lose its energy while sitting.

Punch and Top Speed
Peak Racing LiPo
0-60 ft.: 1.99 sec @ 30.7 mph
1-100 ft.: 2.82 sec @ 34.7 mph
Top Speed: 4.69 sec @ 37.2 mph

Fusion NiMH
0-60 ft.: 2.17 sec @ 29.9 mph
1-100 ft.: 3.03 sec @ 33.5 mph
Top Speed: 4.16 sec @ 35.4 mph

Results: These results pretty much speak for themselves. The LiPo pack provides better acceleration through every increment and a higher top speed. And there's something else to think about too: the LiPo pack was continuously putting up similar numbers, even after a number of runs. The NiMH speed and acceleration were consistently decreasing throughout the life of the charge. The LiPo pack holds its charge better and provides very consistent power throughout its duration.

CONCLUSION
Peak Racing's 4800 LiPo is a tremendous battery pack. It essentially reinvents the way we think about and race electric RC vehicles. The tests prove that the LiPo is in fact lighter, more powerful, and provides more run time than a comparable NiMH pack. If you are shocked by the price tag, keep a couple of things in mind. First, Peak's pack isn't much more expensive a matched NiMH to begin with. Also, LiPo batteries are claimed to have a cycle rate of over 1,000 charges, and you can use a LiPo pack as many times per day was you wish. With that in mind, a LiPo pack will have a much longer effective life and takes the place of two or three NiMH packs. If you race electric, take a serious look at Peak Racing's 4800 LiPo. And to serve you better, we'll be durability testing LiPo packs over the next few issues, so stay tuned as we push LiPo's again and again.