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Inputs And Assumptions
  • Battery Inputs Explained
  • Inverter And Charging Inputs Explained
  • Solar Inputs Explained
Results
  • How To Read The Results Page
  • Understanding Warnings
  • How Battery Sizing Works In GridGap
  • How Inverter Sizing Works In GridGap
  • How Charging Works In GridGap
  • How Solar Sizing Works In GridGap
  • How Solar Controller Results Work
  • Advisory Solar String Guidance Explained
  • Installation Guidance Explained
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  • Essential Solar And Backup Terms
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Inputs Inverter and Charging

Inverter And Charging Inputs Explained

This part of the scenario editor tells GridGap how battery power becomes useful AC output, how much margin should be allowed around the load, and how much recharge time is available when the batteries need to be charged again.

What this section covers

The inverter and charging fields sit between the battery and the load. The battery may have enough stored energy on paper, but the system still needs an inverter that can support the AC demand and a charging plan that can restore the battery in a realistic time window.

Some of these fields are visible in both Simple and Technical mode. Others only appear in Technical mode because they are really about refinement rather than basic setup.

Inverter fields

Inverter / system voltage is one of the most important compatibility fields in the app. The inverter voltage must be equal to or higher than, and should be a multiple of, the battery voltage. For example, a 48 V inverter can work with 12 V, 24 V, or 48 V battery units arranged correctly.

In practical terms, this field tells GridGap what finished DC system voltage the inverter expects from the battery bank. That is why the battery and inverter sections should always be reviewed together.

Inverter efficiency (%) tells the app how much battery-side power becomes useful AC output. If you do not yet know the exact inverter, 90% is a sensible working starting point.

This field matters because real inverters lose energy in conversion. Lower efficiency means more battery energy is needed to support the same AC load. Higher efficiency means less energy is lost between the battery and the appliances.

Charging fields

Grid charge hours tells GridGap how many hours are available to recharge the batteries from grid power. If power is available for 6 hours between outages, you would enter 6.

This is an easy field to underestimate because it sounds simple. In practice, it has a major effect on the charging result. A battery bank that looks perfectly reasonable in energy terms can still be awkward if the available recharge window is short.

In off-grid backup, RV, or boat-style use, many users read this as the available utility or shore-power charging window. The point is the same. The app needs to know how much time the charger has to restore the battery.

Technical controls

In Technical mode, the section becomes more explicit. Grid AC voltage lets you enter the actual AC supply voltage, such as 240, 230, or 110. This grounds the charging and AC-side assumptions in the real supply context.

Inverter headroom factor adds margin above the running load when GridGap recommends inverter size. A value of 1.25 means 25% headroom. This field is about caution and breathing room rather than changing the load itself.

Charger efficiency (%) tells the app how much of the incoming charging power actually reaches the battery. A value around 90% is a common working example. Lower efficiency tends to push charger size upward because more input power is lost before it becomes stored energy.

These technical controls are useful when you want the app to reflect a specific system more closely. They are not mandatory for every early-stage estimate.

Installation and planning fields

If you enable Installation & Protection, the inverter and AC side move into a broader planning context. This layer covers practical fields such as AC output cable runs, cable material, cable type, voltage-drop allowance, installation environment, and protection preferences.

Those fields do not replace final design work. They support the advisory installation guidance in the results and help you think about whether a system that looks fine in pure sizing terms still looks sensible once real-world installation conditions are considered.

It often makes sense to settle the core inverter and charging assumptions first, then use the installation layer as a second pass once the wider system is taking shape.

Good practice

If the charging result looks tight, review both the recharge window and charger efficiency before assuming the battery itself is the problem.

Related articles

How Inverter Sizing Works In GridGap

See how these assumptions appear in the inverter results.

How Charging Works In GridGap

Understand how recharge time and charger behaviour are interpreted.

How To Create A Battery + Inverter Scenario

See how these fields fit into the wider scenario setup.

Previous: Battery inputs Next: Solar inputs
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