---
title: Custom Control Logic Adjustable Parameters
description: "## Introduction The Custom control logic allows users to modify detailed parameters that directly influence how the inverter and battery operate. This provides flexibility but also requires a solid understanding of how the system works. Incorrect configuration may reduce profitability…"
url: "https://docs.qilowatt.eu/en/docs/custom-control-logic-adjustable-parameters/"
updated: "2025-09-17"
category: Optimizer
---

# Custom Control Logic Adjustable Parameters

## Introduction

 The Custom control logic allows users to modify detailed parameters that directly influence how the inverter and battery operate. This provides flexibility but also requires a solid understanding of how the system works. Incorrect configuration may reduce profitability or cause unexpected behavior.

## Prerequisites

 • Qilowatt account created → [Creating a User Account](https://docs.qilowatt.eu/en/docs/creating-a-user-account/)
• Device connected to WiFi → [Connecting a Device to WiFi](https://docs.qilowatt.eu/en/docs/connecting-the-device-to-wifi/)
• Inverter added to the Qilowatt app → [Module Setup](https://docs.qilowatt.eu/en/docs/module-setup/)
• Solar inverter configured → [Solar Inverter Setup](https://docs.qilowatt.eu/en/docs/solar-inverter-setup/)
• Control logic set to *Custom* → [Control Logics](https://docs.qilowatt.eu/en/docs/control-logics/)

## Step-by-step Guide

### 1. Charging and discharging losses

 • Low-voltage batteries (<100 V): typically 14–20% loss per cycle.
• High-voltage batteries: typically 8–14% loss per cycle.
• Adjust values according to your battery’s voltage. The higher the voltage, the lower the current → less heat and lower losses.

### 2. Charging and discharging degradation cost

 • Every kWh charged into or discharged from the battery shortens its lifespan.
• Manufacturers usually guarantee a lifetime of ~6000 cycles. Based on battery cost, capacity, and expected cycles, you can calculate LCOS (Levelized Cost of Storage), which shows the cost per kWh of using the battery.
• LCOS should be split equally between charging and discharging degradation costs.

### 3. Minimum state of charge for selling (Sell Min SOC)

 • Defines how much energy must remain in the battery after a sell command finishes.
• Example: if Min SOC = 15% and Sell Min SOC = 20%, then 5% remains in the battery after selling.
• Each percent left unsold reduces profitability but may be useful in specific cases.

### 4. Minimum state of charge for PV Sell (PV Sell Min SOC)

 • Defines the minimum SOC required before PV Sell mode can activate.
• PV Sell starts in the morning when PV forecast ≥ historical average consumption.
• For fluctuating loads, it’s wise to store some energy in the battery before PV Sell to avoid covering consumption from the grid.

⚠️ Recommended: 2–5% higher than Min SOC. If set too high, expensive morning energy will be stored in the battery, reducing profitability.

### 5. Enable PV Sell

 • Should be disabled if the inverter has no PV input or for specific models (e.g., Deye, Sungrow) where the export limit is more than 2× lower than the total PV capacity.
• If PV input and export work normally, keep this enabled.

### 6. Planned battery state of charge (end of period)

 • The “end of period” = the last hour for which day-ahead market prices are available.
• This setting controls the target battery SOC at the end of that period.
• Recommendation: set around 60% SOC.

### 7. Buy price

 • Minimum extra revenue required for charging the battery.
**• Not recommended**— no practical use case has been identified.

### 8. Sell price

 • Minimum extra revenue required when discharging from the battery.
• Example: if set to 0.10 €, the system will only sell if it earns 10 cents per kWh in addition to covering losses and degradation costs.

## Result

 The Custom control logic enables detailed fine-tuning of inverter and battery behavior. With correct settings, the system can be adapted to very specific use cases. However, incorrect values may lead to lower profitability.

## If it Doesn't Work

 • If the system does not behave as expected, review all parameters carefully and compare with your battery manufacturer’s specifications.
• If the outcome is unsatisfactory, restore default logic → *Maximum Profit* or *Self-consumption*.

⚠️ Qilowatt support **does not provide assistance with Custom settings** or troubleshooting. Responsibility for Custom configuration lies entirely with the user.