Specifications

11
in a higher charge efficiency due to less electrical energy being turned into heat. Their
design also allows for virtually any charging current, which can drastically reduce
charging time. The figure below shows an illustrated diagram of the difference between
wet cell, AGM, and gel cell batteries.
Figure 3 - Comparison between the Construction of Wet Cell, AGM, and Gel Cell Lead Acid Batteries
Permission Pending
Nickel-metal hydride batteries can also be found with a wide range of storage
capacities, sizes, and weights. Those with the capacity to power this system alone,
however, are often hard to find, and very expensive if they are located. In order to avoid
these high cost, large capacity batteries, it may be possible to use multiple smaller
remote controlled car battery packs. The price of these smaller nickel-metal hydride
batteries is reasonable, at between $30 and $70 each battery pack. Nickel metal
hydride battery packs are typically fairly small, weigh about 1 pound, come in 7.2V,
8.4V, and 9.6V battery packs, and are available with a storage capacity up to 5000mAh.
Nickel-metal hydride batteries are designed to be deep cycled frequently, and they don‟t
have a liquid electrolyte meaning they can‟t be spilled and can be oriented in any way
while in use. Unfortunately, most of these battery packs require special charging
procedures, such as a limit on the current, and some require a break period between
cycles. Because we they do not come in the voltage and storage capacity we need, we
will have to buy many of these batteries to make them work for our application.
Perhaps the newest and fastest growing technology in rechargeable batteries is the
lithium ion based battery. Like the most of the previous batteries discussed, these also
come in many different forms and sizes. They range from being small enough to fit in
and power your cell phone, all the way up to full size automotive batteries. They also
don‟t have a liquid electrolyte, and therefore cannot be spilled. Lithium ion based
batteries are much better than any other type of rechargeable battery when it comes to
its storage capacity per unit of mass or volume. However, because of their cost ($1000
and higher), large sized automotive lithium batteries are not very popular. As with the
nickel-metal hydride batteries, a possible way to try to avoid the cost of the large
batteries is to use multiple smaller R/C car lithium polymer battery packs. These smaller