RC Battery Charger Wattage Calculator
What this calculator does
Charging a 6S pack at the same amp rate as a 2S pack requires much more power, and parallel charging multiplies the demand again. This calculator is useful for LiPo users who want to know whether a charger can deliver a selected C charge rate, how long a charge may take, and what size power supply is needed. Enter the cell count, capacity, number of packs, charge rate, and charger efficiency assumptions. The result estimates charger wattage, DC power supply demand, charge current, and practical charge time. Example: a charger that easily charges a 2S 5000mAh pack at 1C may not have enough wattage to charge multiple 6S packs at the same rate. Use this before buying a charger or building a parallel charging setup.
In practical terms: It estimates charger and power-supply wattage so you can see whether your charging setup can support the packs and charge rate you want.
How to use it
Enter pack cell count, capacity, number of packs, and charge rate. Compare the required wattage against your charger and power supply ratings.
Example calculation
Check whether a 200W charger can charge a 6S 5000mAh pack at 1C, then compare it with a 500W charger for the same pack.
FAQ
Why does charger wattage matter?
The charger must provide voltage multiplied by charge current. Higher cell counts need more wattage at the same charge current.
Why can a charger have high amps but still charge slowly?
The amp rating may only apply at low voltage. At higher cell counts, the charger reaches its wattage limit before it reaches the advertised current.
How much power supply wattage do I need?
Use the required charger output wattage plus an efficiency margin. The calculator estimates the DC power supply demand for practical planning.
Does parallel charging require more wattage?
Yes. Parallel charging keeps the voltage the same but increases total capacity and charge current, so wattage demand increases.