Batteries and chargers, explained

• LiPo or NiMH?
• Cells and voltage
• Capacity and run time
• Will it fit my model?
• Traxxas iD and the charge modes
• Which charger?
• Completer packs
• LiPo safety and storage
• Two-pack trucks, cold weather and AA cells
• Where to start

LiPo or NiMH?

Traxxas batteries "all fall into two categories: LiPo (Lithium Polymer) and NiMH (Nickel-Metal Hydride)." NiMH packs use "cylindrical 1.2-volt cells, similar to the AA, C, and D batteries." They "can be discharged completely without harming the battery, and they do not need to be charged before storage," so Traxxas calls them "a good choice for beginners." LiPo packs use "flat 3.7-volt cells" and hold more energy for their size: "your model will have more 'punch,' go faster, and run longer with a LiPo." LiPo packs "should be stored partially charged, and require a LiPo-specific charger," and Traxxas recommends them "for advanced users only."

Cells and voltage

Packs are described by cell count, and cell count sets the voltage. Traxxas NiMH packs come with "6 cells (7.2 volts), 7 cells (8.4 volts) or 8 cells (9.6 volts)." Traxxas LiPo packs come in "2-cell (7.4 volts), 3-cell (11.1v), and 4-cell (14.8v) configurations," written as 2s, 3s and 4s. "Voltage determines how much speed and power your model will have, while capacity determines how long it will run on a charge."

Capacity and run time

"Capacity is indicated in milliamp hours, or 'mAh.'" "The higher the mAh, the longer an electric vehicle will run." Traxxas says "electric vehicles will generally last around 8-to-15 minutes on a charge." Conditions change that, so we don't quote run times per truck.

Will it fit my model?

"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." Each vehicle page states the range in one line: "Runs on a 2s–3s LiPo or a 6–7-cell NiMH" on the TRX-4 trucks, or "Runs on a 3s–4s LiPo. NiMH is not supported" on the Maxx. The Velineon VX3 Brushless trucks (Slash 4X4 Brushless, Stampede 4X4 Brushless, Slash 2WD Brushless, Rustler 2WD Brushless and the 4-Tec 2.0) don't support NiMH at all. If you run LiPo, "ALWAYS: turn Low-Voltage Detection ON."

Traxxas iD and the charge modes

"The exclusive Traxxas iD battery system is the easiest and safest way to charge Traxxas batteries." An iD charger reads "the battery's type, voltage, and capacity" from an iD-equipped pack: "Simply press the 'Start' button and the charger does the rest."

LiPo charging has three modes. Balance is the default, and "We recommend Balance charging for day-to-day use." "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," and "you should place your batteries in Store Mode once a month."

Which charger?

These are the chargers Traxxas lists today. The EZ-Peak models recognize iD packs; the 2970, 2971, 2972, 2973 and 2981 each have a one-button LiPo storage charge; the Live models add Bluetooth and the EZ-Peak Live app. The dual chargers "can charge two batteries at the same time, even if they're different types and capacities." A dash means Traxxas's page doesn't list it.

Completer packs

"You can save money with a Completer Pack that includes the recommended batteries and charger for your model." Here is what Traxxas says is in each one; its pages itemize only the battery and the charger. The chooser on each vehicle page shows the completer Traxxas names for that model first.

LiPo safety and storage

Traxxas: "LiPo batteries can be dangerous if misused or mishandled." Its rules, in its words:

• "NEVER leave batteries unattended while charging."
• "ALWAYS place the battery in a fire retardant/fire proof container and on a non-flammable surface such as concrete."
• "NEVER: charge a LiPo battery using a NiMH charger (or a NiMH charging mode on a combination NiMH/LiPo charger)."
• "ALWAYS: turn Low-Voltage Detection ON when using a LiPo battery in your Traxxas model."
• "NEVER charge or use a LiPo battery or pack that shows any kind of damage or deformity." "Swelling is a sign of internal damage. A battery that has ballooned or swollen even a small amount must be removed from service completely."
• "Never allow children under 14 years old to charge batteries without the supervision of a responsible, knowledgeable adult."

For storage: "LiPo batteries should be stored at 50% capacity," and "Do NOT store LiPo batteries discharged." "Store your batteries in a cool, dry place," "out of the reach of children and pets," and run Store Mode once a month.

Two-pack trucks, cold weather and AA cells

Some big models run two packs at once: the X-Maxx, XRT and Funco take two 4s packs, and the Sledge and Maxx Slash two 3s. Traxxas names the pair; for the X-Maxx it is two 2890X packs or the 2997 completer. The chooser adds two. Charge them one per port on a dual charger, because Traxxas says to "ONLY charge each battery pack individually."

In the cold, "Batteries also lose some power when temperatures approach freezing." Traxxas's example: "Your 3000mAh battery may run 15 minutes in the summer, but might only run 10 minutes in the winter." Traxxas's charge temperature range starts at 32°F.

The transmitter takes "4 AA alkaline or rechargeable batteries (sold separately)." Nitro trucks also need AA cells for the receiver pack, so most take eight; the Revo 3.3 has a rechargeable receiver pack and needs four. The chooser includes Traxxas AA cells by default; uncheck them if you have your own.

Where to start

The Complete your setup chooser on each vehicle page lists the completer or the battery-and-charger pair Traxxas names for that model and gives you a ready-to-run total. Already have Traxxas packs? There is an "I already have" option. Or browse our batteries and chargers page, or ask us which pack fits.