A LiPo pack is picked by cell count, capacity, and discharge rate. A 3S pack reads 11.1 V nominal, and a 4S pack reads 14.8 V nominal. Match the cell count to your motor and ESC, charge at 1C, and store packs at 3.8 V per cell. This guide covers sizing, charging, and safe storage.
What does the S number mean on a LiPo pack?
The S number counts cells in series. Each cell reads 3.7 V nominal and 4.2 V fully charged, so a 3S pack reads 11.1 V nominal and 12.6 V full.
A 6S pack reads 22.2 V nominal and 25.2 V fully charged. More cells mean more voltage, so match the S count to your motor KV and ESC rating.
How much capacity does your aircraft need?
Capacity in mAh sets flight time. A 2200 mAh pack on a 40-inch trainer gives about 8 to 10 minutes of gentle flying.
A bigger pack adds weight, so flight time stops growing past a point. Size the pack to the airframe, not to the largest pack that fits.
How do you charge a LiPo safely?
Charge at 1C, which means 2.2 A for a 2200 mAh pack. A balance charger charges each cell to 4.2 V and stops if one cell drifts high.
The B6neo 2 charger delivers 300 W on DC and 80 W on USB-C PD. The X4 charger runs 4 channels at 500 W on AC for a full day of flying.
How do you store LiPo packs between flying days?
Store packs at 3.8 V per cell, which is the storage voltage for lithium polymer cells. A 3S pack stored reads 11.4 V total.
Keep packs in a LiPo safety bag, away from heat and sunlight. A large safety bag holds several packs, and a 2-pack covers large and small sizes.
How do you check a pack before flight?
A LiPo checker reads each cell voltage in seconds. A 1-8S checker with a low voltage buzzer alarms if any cell drops under load.
The CellMeter8 checker reads up to 8 cells and shows each one separately. Never fly a pack with one cell 0.2 V lower than the rest.
When should you retire a LiPo pack?
Retire a pack that puffs, reads uneven cells after balance charging, or sags hard under load. A puffed pack is a fire risk, not a spare.
Discharge a retired pack to 0 V with a 3-in-1 balancer and discharger, then recycle it at a battery drop-off. Never throw a LiPo in household trash.
Quick comparison
| Pack | Nominal voltage | Full voltage | Storage voltage |
|---|---|---|---|
| 2S | 7.4 V | 8.4 V | 7.6 V |
| 3S | 11.1 V | 12.6 V | 11.4 V |
| 4S | 14.8 V | 16.8 V | 15.2 V |
| 6S | 22.2 V | 25.2 V | 22.8 V |
Frequently asked questions
What does 1C mean when charging?
1C means a charge current equal to the pack capacity in one hour. A 2200 mAh pack charges at 2.2 A at 1C.
Can I leave a LiPo fully charged overnight?
Yes for one night, but not for weeks. A pack left at 4.2 V per cell for weeks loses capacity and can puff.
What is the lowest safe voltage per cell in flight?
Land when a cell hits 3.5 V under load, and never let a cell drop below 3.0 V. A low voltage buzzer alarms at the level you set.
Do I need a fireproof bag for LiPo packs?
Yes. A LiPo safety bag contains flame and heat if a pack fails. Charge and store packs in the bag, on a non-flammable surface.
Parts used
LiPo Battery Voltage Checker 1-8S with Low Voltage Buzzer Alarm, 6-Pack, $29.99. 6-pack of 1-8S LiPo battery voltage checkers with low-voltage buzzer alarm and LED indicator. Plugs into the balance lead, powered by the pack. Ships from NY, USA.
LiPo Safety Bag 2-Pack (Large + Small), $26.99. 2-pack of fire-retardant LiPo safe bags, one large and one small. For charging, storage, and transport of LiPo batteries.
3-in-1 Battery Voltage Checker Balancer and Discharger, $12.00. US stock, ships fast from NY, USA. 3-in-1 Battery Voltage Checker Balancer and Discharger. Quality checked before shipping.
Large LiPO Safe Bag, $7.00. US stock, ships fast from NY, USA. Large LiPO Safe Bag. Quality checked before shipping.
B6neo 2 Smart Charger, DC 300W / PD 80W, $84.99. SKYRC B6neo smart charger with DC 300W and PD 80W input. Charges LiPo, LiFe, Li-ion, LiHV, NiMH, NiCd, and Pb packs. Compact multi-function charger. Ships from NY, USA.
X4 4-Channel Smart LiPo Charger, AC 500W, $182.99. Ovonic X4 500W 4-channel smart LiPo battery charger, 15A per channel. Charge four packs at once for cars, FPV, and drones. Ships from NY, USA.
CellMeter8 LiPo Battery Checker, $19.99. CellMeter8 8-cell LiPo battery checker and balancer. Ships from NY, USA.
2S-6S JST-XH Balance Charging Adapter Board, $7.99. 2S-6S JST-XH balance adapter board for LiPo chargers. Replacement balance board for XH style ports. Ships from NY, USA.
B6 80W Digital Balance Charger, T/Tamiya/XT60 Plug, $49.99. Imax B6 80W digital balance charger for LiPo, NiMH, NiCd, and Li-ion packs. Includes T-plug, Tamiya, and XT60 charge leads. Ships from NY, USA.
LiPo Low Voltage Buzzer Alarm + Battery Voltage Indicator Tester, 1S-8S, $4.85. LiPo low-voltage buzzer alarm + voltage tester for 1S: 8S packs : buzzer + red LED when any cell drops below your set threshold. Single unit. Ships from NY, USA.
XT60H Male + Female Connector Set with Sheath Housing, 10-Pair, $11.87. XT60H male + female bullet connector set with sheath housing : gold-plated copper, 60A max. 10-pair. Ships from NY, USA.
5A Switch-Mode UBEC, 2-8S LiPo, $11.00. 5A switch-mode UBEC for 2 to 8S LiPo. Handles bigger servo loads than the 3A version without breaking a sweat.
Related buying guides on Quality RC Parts
RC Battery Chargers in the USA
UBECs, BECs and Power Distribution for RC in the USA
Browse all the guides on the Quality RC Parts Drone Guides hub, or start at the Quality RC Parts store.
Sources
Quality RC Parts stocks parts in New York, USA and ships in-stock orders in 1-2 business days.
Last updated: 2026-11-10.