How to Choose a Drone Battery: Voltage, Capacity, C-Rating and Chemistry
The short version: match the battery’s voltage (cell count) to your drone’s rated input first, then size capacity (mAh) to the flight time you need, and finally pick a C-rating that covers your platform’s peak current draw with headroom. For most FPV and multirotor builds, a 4.2 V-per-cell LiPo between 3S and 6S is the right default. For heavy-lift, long-endurance and commercial platforms, a high-voltage (LiHV) or smart pack usually earns its price in extra endurance and operational predictability.
The table below maps common applications to the combination that tends to fit, as a starting point before you confirm against your own drone’s specifications.
| Application | Usual chemistry | Typical cell count (S) | Typical capacity |
|---|---|---|---|
| FPV racing / freestyle | LiPo (high C) | 4S–6S | 1,000–1,800 mAh |
| Cinematic FPV / mid multirotor | LiPo or LiHV | 4S–6S | 5,000–8,000 mAh |
| Survey / mapping multirotor | LiPo, LiHV or smart | 6S–12S | 10,000–22,000 mAh |
| Inspection / commercial | Smart battery | 6S–12S | 16,000–36,000 mAh |
| Agriculture / heavy lift | LiHV (high capacity) | 12S+ | 25,000–41,000 mAh |
Start with voltage and cell count
Cell count is the one characteristic you cannot compromise on. A pack with the wrong voltage will either refuse to power the system or damage the ESC and flight controller.
Each LiPo cell is 3.7 V nominal (4.2 V fully charged), so a 3S pack is 11.1 V nominal, 4S is 14.8 V, and 6S is 22.2 V. High-voltage packs run 3.8 V per cell nominal (4.35 V charged). Your drone’s motor, ESC and PDB list a supported voltage range — usually expressed as a cell count, such as “3S–6S”. Choose a pack whose nominal voltage sits inside that range, and confirm the ESC firmware accepts the higher full-charge voltage before moving to LiHV.
Pick capacity for flight time
Capacity (mAh) is your fuel tank. All else being equal, flight time scales roughly with usable watt-hours, and a larger pack extends endurance at the cost of weight.
Estimate whether a capacity fits by comparing watt-hours to your platform’s cruise power. A rough hover figure for a 1–2 kg multirotor is 150–250 watts; divide the pack’s watt-hours (voltage × amp-hours × usable 80%) by that draw to approximate minutes. For example, a 6S 10,000 mAh LiPo holds about 222 Wh (22.2 V × 10 Ah), of which roughly 178 Wh is safely usable, on the order of 40–70 minutes at light cruise depending on load. Use that only as a sanity check — real endurance depends on prop, payload and flying style.
Size the C-rating to your current draw
The C-rating states how fast the pack can discharge as a multiple of its capacity. A 5,000 mAh (5 Ah) pack at 60C is rated for up to 300 A continuous (5 × 60), though real-world packs rarely sustain that without voltage sag and heat.
Estimate your platform’s peak draw, then choose a pack whose C-rating × capacity comfortably exceeds it by at least 20–30%. High-C packs (60C and above) exist for racers and freestyle pilots whose instant current spikes are punishing; a mapping or inspection drone that cruises at a steady low draw does not need a 100C label, and will be happier with a lower-C, higher-capacity pack.
Choose a chemistry
The two chemistries on this site are standard LiPo (4.2 V/cell) and high-voltage LiHV (4.35 V/cell). LiHV stores roughly 5–10% more energy per gram, which typically translates to a few percent more flight time at the same weight; the tradeoff is slightly reduced cycle life and a hard requirement that both charger and ESC tolerate the higher voltage. A full breakdown is in the LiPo vs LiHV comparison.
Standard or smart battery
A standard pack is a bare cell stack: lighter, cheaper, and fully dependent on the charger for balancing and safety. A smart battery builds in a management system that self-balances cells, reports charge and health over a data interface, and protects against over-charge and over-discharge. For commercial operations where downtime and battery logging matter, a smart pack such as the Tattu NEO line saves real labor and risk. For a race build where every gram counts, the standard pack still wins.
Confirm the connector and fit
Finally, verify the discharge connector (XT60, XT90, EC5, AS150 and so on) matches your PDB or ESC harness, and that the pack’s physical dimensions fit the tray or strap layout. Adapters add resistance at the exact point where current is highest, so a matching connector is better than an adapted one.
Decision summary
- Confirm the platform’s supported voltage range and lock in the cell count.
- Size capacity to the endurance you need, watching the weight penalty.
- Over-rate the C-rating by 20–30% above peak current draw.
- Pick LiPo unless the platform and charger support LiHV and you want the extra endurance.
- Choose smart over standard only when logging, self-balancing and protection justify the cost and weight.
- Match the connector and confirm physical fit.
Frequently asked questions
What does the “S” in a battery mean?
It is the number of cells wired in series. Each LiPo cell is 3.7 V nominal, so a 3S pack is 11.1 V and a 6S pack is 22.2 V.
Can I use a higher-capacity battery than the drone specifies?
Only if the voltage stays within the rated range and the extra weight does not push the motors and flight controller outside their limits. Capacity is flexible; voltage is not.
What C-rating do I actually need?
Enough that C-rating × capacity in amps exceeds your platform’s peak draw by 20–30%. A racing quad on a 1,300 mAh pack may want 100C or more; a mapping drone cruising at low draw does fine below 25C.
Which battery lasts longer in the air?
At a given total weight, LiHV delivers slightly more flight time for the same mass. At a given capacity, a larger mAh pack flies longer regardless of chemistry.
Where can I buy the right battery?
Browse the Tattu UAV batteries and FPV batteries ranges, or contact the team for a recommendation matched to your specific platform.