Learn the Basics About Battery Types, Ratings, and Charging
At Traxxas the goal is to make the RC hobby fun and exciting for people of all skill levels. If you are new to RC, you may have some questions about batteries and how to charge them. Traxxas vehicles use high-power rechargeable batteries to achieve their extreme performance. These batteries are much more powerful than the alkaline batteries you typically buy in a store and require some additional care. This article explains the differences between batteries, how to choose the right ones, and how to charge your batteries.
Battery Charging Do's & Dont's
NEVER: leave a battery unattended while charging, regardless of type
NEVER: charge a LiPo battery using a NiMH charger (or a NiMH charging mode on a combination NiMH/LiPo charger).
NEVER: charge a battery that has swollen, melted, or otherwise appears to be damaged.
ALWAYS: turn Low-Voltage Detection ON when using a LiPo battery in your Traxxas model. Learn more about Low-Voltage Detection here.
ALWAYS: charge LiPo batteries in a fire-retardant/fireproof container. Place the container on a non-flammable surface such as concrete.
ALWAYS: disconnect (unplug) the battery from the electronic speed control after you finish running your model.
DO: use iD® Traxxas batteries and iD® chargers for an easier and safer charging solution.
Understanding Capacity and Voltage
The primary specs you’ll consider when choosing a battery are voltage (determined by how many cells are in the pack) and capacity (how much energy is stored in the battery). Voltage determines how much speed and power your model will have, while capacity determines how long it will run on a charge. Capacity is indicated in milliamp hours, or “mAh.” This number refers to the amount of current in milliamps the battery can supply for one hour. All you need to remember is that the higher the capacity number, the longer your model will run on each charge.
Capacity is displayed in mAh while voltage is displayed with V.
Note that batteries are not universal; a battery may not be the right size to fit in your model or it may have more voltage than the power system is rated to handle. Traxxas makes finding compatible batteries easy: just look up your model at Traxxas.com, and then click Batteries on the menu to view all of the NiMH and LiPo packs that can be used in your model.
Understanding Battery Chemistry
Traxxas offers a wide assortment of battery sizes, voltages, and capacities, but when it comes to the chemistry inside the batteries, they all fall into two categories: LiPo (Lithium Polymer) and NiMH (Nickel-Metal Hydride). Each type has different advantages to consider when choosing a battery or batteries for your model.
Power Cell NiMH batteries have seven 1.2-volts cells, for a total of 8.4 volts.
NiMH battery packs are composed of cylindrical 1.2-volt cells, similar to the AA, C, and D batteries that we’re all used to installing in flashlights, TV remotes, and other devices. The rolled-metal construction of the individual cells, and the double-welded tabs Traxxas uses to connect the cells, makes them extra rugged. NiMH batteries can be discharged completely without harming the battery, and they do not need to be charged before storage. Traxxas NiMH batteries are offered with 6 cells (7.2 volts), 7 cells (8.4 volts) or 8 cells (9.6 volts).
LiPo battery packs are composed of flat 3.7-volt cells. The cells are stacked and enclosed in a tough, semi-rigid wrap. Traxxas LiPo batteries are offered in 2-cell (7.4 volts), 3-cell (11.1v), and 4-cell (14.8v) configurations. LiPo batteries have greater “energy density” than NiMH batteries, meaning they have more voltage and capacity than a NiMH battery would of the same volume. LiPo batteries also sustain a higher voltage for a greater duration of each run, so your model will have more “punch,” go faster, and run longer with a LiPo than it would with a comparable NiMH pack.
NEVER charge a LiPo battery using a NiMH charger (or NiMH charging mode on a combination NiMH/LiPo battery charger). LiPo batteries can be damaged by over-discharging, which is why the electronic speed control on all Traxxas models has built-in Low-Voltage Detection to alert you when LiPo batteries have reached their minimum voltage (discharge) threshold. LiPo batteries should be stored partially charged, and require a LiPo-specific charger.
Charging Your Batteries
Traxxas iD chargers are the safer, faster, and most convenient way to charge Traxxas batteries. Patented technology allows an iD-equipped charger to identify automatically the battery’s type, voltage, and capacity. Simply press the “Start” button and the charger does the rest. This technology only works with Traxxas iD batteries; older, non-iD Traxxas batteries can be charged in manual mode by setting the battery type and charge rate.
Traxxas Dual iD chargers can charge two batteries at the same time, even if they’re different types and capacities. The charger sets itself automatically.
LiPo Charging Modes
When charging LiPo batteries, iD chargers will default to Balance charging. We recommend Balance charging for day-to-day use. You can also select Fast Mode or Store Mode. Fast Mode will finish charging the battery sooner, but may reduce your run time slightly. Store Mode is used to make sure the battery is approximately 50% charged for storage. Use this mode if you won’t use your LiPo battery for a week or more. If the battery is already more than 50% charged, the iD charger will discharge it to 50%.
Balance charging is the default setting, and delivers the most complete charge.
Caring for Your Batteries
A LiPo battery is said to be “balanced” when each cell is charged to the same voltage. It takes a little longer to balance charge a battery, but doing so ensures that you’ll get the longest run time from each charge. Balance charging also helps extend your LiPo battery’s overall life by preventing over-discharging. Low-Voltage Detection in all Traxxas speed controls is designed to alert you when the battery’s voltage drops below 3.2 volts per cell; however, the speed control reads total pack voltage and not the voltage of individual cells. For example, if you plug a 3-cell LiPo into your speed control, the speed control will alert you if the battery voltage drops below 9.6 volts (3.2 x 3 = 9.6). But if your battery is not balanced, that 9.6 volts might actually represent individual cell voltages of 3.3v, 3.3v, and 3.0v. The 3.0v cell has been over-discharged, which shortens the life of the pack. Balance charging your LiPo packs assures each cell is equally charged so their voltages will match as the cells discharge.
Maintaining Your Batteries
Inspect your batteries after every use to make sure they have not been damaged. Wipe your batteries down and check for frayed wires, missing insulation, and other signs of damage. Store your batteries in a cool, dry place. If you used LiPo batteries in your vehicle until the Low-Voltage Detection activated, your batteries will be nearing their low-voltage threshold. LiPo batteries should not be left in this depleted state. If you plan to reuse the LiPo batteries that day, recharge them soon after using them. If you do not plan to reuse the batteries immediately, use the Store Mode on your Traxxas iD® charger to prepare them for storage. For optimal performance and long battery life, you should place your batteries in Store Mode once a month.
Millions of devices containing lithium batteries are used and enjoyed daily in devices such as laptops, tablets, smartphones, flashlights, and even full-size automobiles. LiPo batteries are safe and stable as long as caution and common sense are used. However, LiPo batteries can be dangerous if misused or mishandled. Specifically, short circuiting or puncturing a LiPo will result in rapid, destructive discharging and fire. Never, ever intentionally damage a LiPo battery. Over-charging, over-discharging, or improperly charging a LiPo battery will also damage or destroy it. Always use a LiPo-specific charger with LiPo batteries, and choose the correct settings for your battery. Again, Traxxas iD LiPo batteries and a Traxxas iD charger are always the safer, most convenient way to enjoy LiPo battery performance.
In rare cases, a fault or hidden damage in a LiPo battery or a malfunction with a charger can cause the battery to short circuit or over-charge and create the risk of fire with the potential for damage or destruction of the battery and/or property. For this reason, Traxxas recommends LiPo batteries always be charged in a fire-retardant container away from flammable materials and surfaces.