What "3S", "4S", "6S" actually mean
The "S" number is how many cells are wired in series inside the pack. More cells means more voltage, which means more speed and more strain on the whole drivetrain. Every ARRMA is sold around a target cell count - match it or you either bog the truck down or cook it.
| Pack | Nominal voltage | Full charge | Feel |
|---|---|---|---|
| 2S | 7.4V | 8.4V | Small-scale (GROM) only |
| 3S | 11.1V | 12.6V | Controllable, beginner-friendly |
| 4S | 14.8V | 16.8V | Noticeably faster step-up |
| 6S | 22.2V | 25.2V | The basher sweet spot |
| 8S | 29.6V | 33.6V | Extreme - experienced only |
Why a "6S" ARRMA takes two 3S packs
This is the "2 3s" question people search for constantly. Most ARRMA 6S trucks do not use a single 6S pack - they have two battery trays and you run two 3S packs wired in series (2 x 3S = 6S). It is cheaper to buy, charge and replace two 3S packs than one big 6S, and you can drop to a single 3S per tray if you ever want a slower setup. In the same way, an 8S truck runs two 4S packs (2 x 4S = 8S).
So when a listing says the truck is 6S, you are shopping for a matched pair of 3S packs, not one battery.
Shop matched 3S LiPo packs on Amazon →
Connectors, capacity and C-rating
Three specs decide if a pack fits and performs:
Connector
Most 6S/8S ARRMA trucks use EC5 plugs from the factory; smaller 3S/4S models often use EC3 or IC3. Check your truck, because a mismatched plug means soldering or an adapter. When in doubt, search for a pack listed as "for ARRMA" with the matching plug.
Capacity (mAh)
Higher mAh = longer runtime and more weight. For a big basher, 5000-6500mAh 3S packs are the common sweet spot between run time and not being a brick.
C-rating
This is how hard the pack can dump current. Big brushless ARRMA trucks pull huge current on the throttle, so do not go cheap here - a pack rated too low will sag, get hot and die early. Aim for a well-reviewed 50C+ pack for 6S bashing.
Compare ARRMA-ready 6S LiPo packs →
You also need a charger
A LiPo must be balance charged - the charger reads every cell and keeps them even. A basic "balance charger" that handles up to 6S covers most ARRMA setups; for 8S you often charge the two 4S packs separately or use a dual-port charger. Do not use a random wall brick.
See balance chargers for ARRMA on Amazon →
LiPo safety - the short version
LiPo chemistry is unforgiving if you abuse it. Four rules keep you safe:
1. Charge on a non-flammable surface or in a LiPo bag, and never leave it unattended.
2. Never run a cell below 3.0V - if the truck slows and the low-voltage cutoff kicks in, stop. Draining a LiPo flat ruins it.
3. Store packs at storage voltage (about 3.8V per cell), not full, if you are not running for a few days.
4. A puffed, hot or damaged pack is done - retire it safely, do not charge it.
Get this part right and the batteries outlast several sets of tyres. Get it wrong and it is the most expensive lesson in the hobby.
Not sure which power class you are buying for? Start with the beginner guide, or compare 6S vs 8S.