How Battery Sizing Works In GridGap
The Battery tab shows both the energy burden the battery must carry and the practical battery bank needed to carry it under the current scenario assumptions. This is where a theoretical storage requirement becomes a physical bank layout.
What the Battery tab is showing
Read the Battery tab in two stages. First, look at how much energy the battery is being asked to supply. Then look at how that requirement turns into a real bank once battery voltage, system voltage, depth of discharge, and practical rounding are taken into account.
This is why the final battery answer is often larger than a rough back-of-envelope estimate. The app is not only looking for enough theoretical stored energy. It is also building a bank that can exist in a usable system configuration.
Input reminder cards
The first cards in the Battery tab help you confirm what kind of battery the scenario was based on. Battery Unit kWh / Ah shows the battery unit size that was entered. Battery Entry shows whether the battery was entered in kWh or Ah. Battery Voltage shows the unit voltage used in the scenario.
These cards are easy to skip, but they are useful when a result looks surprising. They help you confirm that the app interpreted the battery in the way you intended before you start questioning the rest of the result.
Requirement build-up
The heart of the tab is the requirement chain. It begins with Battery output required. This is the energy the battery must actually deliver to support the scenario.
From there, the tab walks through a series of sizing steps: Nominal capacity required, Temperature adjusted capacity, Peukert factor, and Final required battery capacity. Not every scenario will make all of these equally important, but together they explain why the raw energy burden is not the same thing as the final required bank size.
Required system Ah then converts the final requirement into amp-hours at the chosen system voltage. This is useful because many real battery selections and bank layouts still have to be understood in system-level Ah terms even when the energy logic began in watt-hours or kilowatt-hours.
Bank layout and actual installed capacity
Once the required capacity is known, the result moves from theory to physical arrangement. Series count tells you how many battery units are needed in series to reach the system voltage. Parallel strings shows how many parallel paths are needed to reach the capacity target.
Total batteries is the rounded physical battery count that falls out of that arrangement. This is often the first number users focus on, but it makes more sense when read together with the series and parallel layout behind it.
Actual installed capacity shows what the rounded bank really provides once whole batteries and practical stringing are taken into account. Actual usable capacity shows how much of that bank is realistically usable under the selected discharge assumptions.
This distinction matters because the bank you can physically build may overshoot the exact minimum requirement. That is normal. Batteries are installed as whole units, not as perfect fractions.
Reserve, depletion, and margin
The last part of the Battery tab is about comfort margin. Depletion percent shows how hard the modeled scenario pushes the bank. Higher depletion means the bank is being used more deeply relative to its usable capacity.
Reserve Wh and percent show what remains after the scenario demand has been applied. This is one of the most practical checks in the tab. A result may be mathematically valid and still feel tight if reserve is thin.
If the bank layout looks efficient but reserve is small and depletion is high, the battery side deserves a second look. That does not always mean the result is wrong. It may simply mean the scenario is closer to the limit than is comfortable for the use case.