How to Choose a Battery for Your BNF Quad
Every BNF page on this site has a battery block that answers this for a specific model. This guide is the method behind those recommendations, so you can sanity-check any pack for any quad.
Step 1: Cell count is not negotiable
The manufacturer rates the powertrain (motors + ESC) for a cell range. A "3-6S" quad genuinely accepts either; a "6S" freestyle quad on 4S flies like wet cardboard, and 6S into a 4S-only build releases smoke. Find the rating on the quad's spec page here, or on the motor's own page - motor bench tables show which voltage the manufacturer actually tested.
Step 2: Capacity is a window, not a target
Bigger packs fly longer only until their weight eats the gain. The window that works:
| Class | Typical capacity |
|---|---|
| 65-75 mm whoop (1S) | 300-450 mAh |
| 3-3.5" (4S) | 650-850 mAh |
| 5" freestyle (6S) | 1000-1400 mAh |
| 7" long range (6S Li-ion) | 3000-4000+ mAh |
Within the window, smaller = more agile, bigger = longer flights. Outside it, both agility AND flight time get worse - the extra grams demand more current, which drains the extra capacity. The flight time calculator makes the trade visible: add capacity AND weight, watch minutes stop growing.
Step 3: The weight trap
The pack is often 30-40% of all-up weight. A 5" quad at 380 g dry with a 230 g 1500 mAh pack carries more per motor than the same quad with a 180 g 1100 mAh pack - and thrust-to-weight, not capacity, is what you feel on the sticks. Check the effect with the thrust-to-weight calculator, pre-filled with real bench thrust on every motor page.
Step 4: Connector - annoying but simple
XT60 on 5"+ quads, XT30 on 3-4" and lighter, BT2.0/PH2.0 on whoops. Adapters exist but add resistance and failure points; matching natively is better. Every battery page here lists the connector; whoop packs note BT2.0 vs PH2.0 explicitly because the two look identical and are not.
Step 5: C-rating, briefly
For 5" freestyle, any honest name-brand pack labeled 75C+ delivers what the quad needs. The printed number itself is marketing - here's what actually matters. For long range, ignore C-ratings entirely and read cell datasheets - Li-ion is a different game.
Shortcut
Open your quad's page in the quads hub. The battery block lists packs from our battery database that already match its cell count, capacity window and connector - with weight and price per Wh to compare. The flight-time calculator on the same page is pre-filled with that quad's cruise current, so "how long will it fly" takes one click.
Related: LiPo care · C-rating truth · AUW and why it matters