Power Station Runtime & Energy Balance

When to use it

For two device loads sharing one time window, such as an outdoor work or camping plan. Enter rated Wh, starting and reserve charge, and an effective delivery fraction appropriate to your equipment and conditions. The example percentage is a chosen assumption, not a specification for every power station.

Inputs

Calculation method

Charge-window energy = rated Wh × (starting charge − reserve charge). Multiply it by the chosen delivery fraction, add the two average loads, and divide deliverable Wh by total W for hours. At 1000 Wh, 90% start and 10% reserve, the window holds 800 Wh. A chosen 85% delivery fraction gives 680 Wh. Loads of 60 W and 10 W give 68/7 hours. Eight hours needs 560 Wh, leaving 120 Wh.

1,000 [Rated battery energy Wh] × (90 [Starting charge relative to rated energy]%-10 [Charge to keep at the end]%) → Energy in the chosen charge window Wh

Energy in the chosen charge window Wh × 85 [Effective delivery fraction under the chosen conditions]% → Estimated energy deliverable to devices Wh

60 [Device A average power W] + 10 [Device B average power W] → Combined average device load W

Estimated energy deliverable to devices Wh/Combined average device load W → Estimated runtime for that load h

Combined average device load W × 8 [Target time for both loads h] → Energy needed for the target time Wh

Estimated energy deliverable to devices Wh-Energy needed for the target time Wh → Energy remaining or shortfall Wh

Change one input

Change only device A from 60 W to 100 W. Combined load becomes 110 W, runtime becomes 68/11 hours, and eight hours needs 880 Wh. The energy balance changes from 120 Wh spare to a 200 Wh shortfall.

Results are displayed to at most two decimal places; later formulas use unrounded values.

Scope and limits

• Use average device power for the chosen period.
• Delivery fraction is an assumption, not a universal efficiency.
• Enough energy does not prove output compatibility.

Rated energy and target time must be positive. Require 0 ≤ reserve < start ≤ 100%, 0 < delivery ≤ 100%, nonnegative individual loads and positive total load. The delivery fraction is a simplified aggregate assumption; it is not a fixed planning margin. Do not deduct the same loss twice. Cycling loads, temperature, self-consumption and battery condition can change actual runtime. Check ports, continuous output and startup surge separately. No Ah/mAh conversion, charging, solar forecast or critical-power guarantee is included.

Energy and output are separate: EcoFlow.

Download and import into Calvance to edit the numbers. The canvas does not reject every invalid input; check the stated ranges.

Common questions

Does a higher output wattage mean longer runtime?

No. Stored energy and device consumption determine this estimate; output limits are a separate check.

Can I enter a fridge nameplate wattage?

Use a representative average for the period. Compressor cycling makes continuous nameplate-power assumptions unreliable.

How to import your template

We recommend using the latest version of Calvance.

1. Save the file. Choose Download template and save the .calvx file to Files on your iPhone or iPad. From a computer, you can send it to your device with AirDrop.
2. Open Import. In All Canvases in Calvance, tap the add button to open the template screen, then choose Import.
3. Choose the file. Select the saved .calvx file to create your own canvas. Importing uses one canvas from your allowance.
4. Edit and check. Check the results against the worked example, then add your numbers. Duplicate the canvas to keep different versions.

Download .calvx file