Batteries
LiPo Charger Guide: Watts, Amps, Parallel Charging and Safe Charging for Drone Batteries
A charger is sized by watts: amps at the 1C rate times the pack’s full voltage, so a 6S 1300 mAh pack needs 33 W and four of them on a parallel board need 131 W, while a 12S agri pack needs 800 W. This guide runs the numbers for every pack size, sorts AC, DC and dual-channel chargers, covers the chemistry settings that must be right, and the parallel-charging and safety rules.
Published 9 October 2026 · by the Fioparts team, Gurugram
The one calculation: watts
A charger is limited by its power (W), its current (A) and the cell count it accepts. Charging at the normal 1C rate means the current in amps equals the pack’s capacity in Ah, and the power needed is that current times the pack’s voltage at the end of charge (4.2 V per cell):
| Pack | 1C current | Power at 4.2 V / cell | Charger class |
|---|---|---|---|
| 1S 300 mAh whoop, six at once | 0.3 A each | 8 W | USB-C whoop hub |
| 4S 1500 mAh | 1.5 A | 25 W | Any 50 W AC charger |
| 6S 1300 mAh | 1.3 A | 33 W | 50 W AC charger |
| 4 × 6S 1300 mAh on a parallel board | 5.2 A | 131 W | 200–300 W DC charger |
| 6S 5000 mAh (7″ long range) | 5 A | 126 W | 200–300 W |
| 12S 16,000 mAh agri pack | 16 A | 806 W | 650–1200 W, 8S+ channel or two 6S channels |
| 14S 28,000 mAh agri pack | 28 A | 1,646 W | Dual 1 kW charger or a dedicated agri charger |
If the pack needs more watts than the charger has, the charger simply slows down — a 6S 5000 mAh pack on a 50 W charger takes 2.5 hours instead of 1. That is safe. What is not safe is a charger whose cell-count limit or chemistry setting is wrong for the pack.
Charger types
- AC chargers plug into the wall and are limited to 30–60 W by their built-in supply (iMAX B6AC class, ToolkitRC M4AC 30 W, C4 50 W, SkyRC B6AC Neo at 60 W on AC). Right for one 4S / 6S pack at a time or a 2S–4S fleet.
- DC chargers take 11–30 V from a separate power supply or a car battery and deliver 200–650 W (HOTA T6 300 W, SkyRC B6 Neo 200 W, ToolkitRC M6D 500 W dual, HOTA T8 650 W, 1–8S). Add a power supply — ToolkitRC ADP100 / 200 / 450 / 750, HOTA T330 — sized to the charger; many now accept 100 W USB-C PD as a travel option.
- AC / DC dual-input gives both: HOTA D6 Pro (325 W, two channels), HOTA T8 Ultra GaN 650 W, SkyRC D750 MIX, SkyRC B6AC Neo. The convenient choice for a growing fleet.
- Dual-channel chargers (D6 Pro, M6D, D750, PC1080neo) run two packs, or two parallel boards, independently.
- Whoop 1S hubs charge two to six 1S packs at once from USB-C (GEPRC GEP-C1, HGLRC Thor 6-port, GEPRC WooPower W63, iFlight 1S LiHV hub, ViFly). Set LiPo or LiHV per pack — see 1S whoop chargers.
- Agri chargers and hubs for 12S–14S packs: dual 1 kW units (ToolkitRC M8DAC 1200 W, SkyRC PC1080neo) and the Ultra Power UP-H28 hub, under agri batteries and chargers.
Chemistry settings
Every balance charger asks for the chemistry, and it sets the voltage the pack stops at. Getting this wrong is the common way to ruin or ignite a pack:
| Chemistry | Full | Storage | Packs |
|---|---|---|---|
| LiPo | 4.20 V / cell | 3.80–3.85 V | Standard FPV and agri packs |
| LiHV | 4.35 V / cell | 3.85 V | 1S whoop packs, “HV” 2S–6S packs |
| Li-ion | 4.20 V / cell | 3.60–3.70 V | 18650 / 21700 packs, Molicel |
| LiFe (LiFePO4) | 3.65 V / cell | 3.30 V | Transmitter and 32140 packs |
A LiHV pack charged as LiPo loses a little capacity and nothing else; a LiPo pack charged as LiHV is over-charged. Our charger listings carry a chemistry filter, and the kit builder and product pages only pair a charger with a pack whose chemistry it supports.
Parallel charging
A parallel board (XT60 + XH, or XT30 for small packs) lets a 200 W+ charger fill four to six packs in the time of one. The rules are strict: every pack on the board must have the same cell count, be within about 0.1 V per cell of each other before connecting (a cell checker takes a second), and the charger current is the sum of the packs’ 1C rates — four 1300 mAh packs → 5.2 A. Plug the main leads in first, balance leads second, and watch the first minute. Never parallel packs of different chemistry or cell count.
Balance leads and plugs
FPV packs use JST-XH balance plugs (one pin more than the cell count); whoop 1S packs use BT2.0, PH2.0 or XH 2-pin, and the hub must match. Balance-lead extensions save the pack’s own plug from wear, and AB clips stop the lead pulling out in the bag. The main lead is XT60 on 4S–6S packs, XT30 on 2S–4S small packs, XT90 on large and agri packs — chargers list their charge connector, and an adapter lead is a legitimate answer where it differs.
Safety that is not optional
- Charge in a LiPo bag or an ammo box, on a non-flammable surface, never unattended.
- Do not charge a pack that is puffed, below 3.0 V per cell, or still warm from flying.
- Set the cell count by hand on chargers that ask; auto-detect can mis-read a damaged pack.
- Storage-charge any pack you will not fly within two days; full packs age fastest.
- Dispose of dead packs through a collection point under the Battery Waste Management Rules, not in household waste.
Browse chargers and 6S balance chargers; the LiPo battery guide covers the packs themselves and the Li-ion guide the cells.