Hi Im new to Wonderwatt and have learning difficultys and have tot been able to find a good schedule set up guide I can follow. So I have taken to ChatGPT and if this is not allowed please let me know but I am going to show the question I put to ChatGPT and its answer and would love those in the know on here to comment on it and point me in the right direction as i know ChatGPT is not always correct. Any inpuy would be appriciated. TIA
My Question :
Will Wonder watt automated how much and when my battery will charge to ensure it is cost efficient so in the cosy slots do I just enter the full 3 hours for first one and 3 hours for second and 2hours for third one because at the moment I do charge in those slots but not for the full time they are available. In 1 of the slots I only charge for 30 minutes. So my question is will WonderWatt automate how long it charges within the hourly slots allowing for SOC and my daily usage and weather into account.
ChatCPT answer :
Excellent question — and you’ve actually hit on one of the most important distinctions in how Wonder Watt operates depending on how you configure it.
Let’s break it down clearly 👇
⚙️ 1️⃣ What Wonder Watt can do
Wonder Watt has two modes for handling tariffs like Octopus Cosy:
🧩 A. Fixed Schedule Mode
You tell it exactly when to charge (start/end times).
The inverter then follows that instruction, regardless of weather or SOC (State of Charge).
This is the “manual scheduling” route — ideal if you want full control or if your inverter is not fully supported for smart optimisation.
✅ Works with almost all Growatt inverters.
❌ It won’t adjust duration or power automatically.
🤖 B. Smart Optimisation Mode
You just tell Wonder Watt what tariff you’re on, your battery capacity, and your goals (e.g. “minimise import cost” or “stay full for evening heating”).
Then Wonder Watt will calculate when and how much to charge automatically, within your tariff’s cheap windows.
It uses forecast solar generation, weather, and your historic consumption to decide whether to charge the whole 3 hours or maybe only 30 minutes.
✅ This is what you were expecting — it “decides” dynamically.
❌ Only works if your inverter allows Wonder Watt full API control (Growatt has partial support — more below).
⚠️ 2️⃣ For your setup (Growatt inverter + batteries)
At the moment:
Wonder Watt cannot directly control Growatt battery charge rates or SOC targets dynamically the way it can with GivEnergy, SolarEdge, or Solis.
It can, however, schedule fixed charge windows and update them automatically each day based on forecasts (so it’s “semi-smart”).
In other words:
Wonder Watt can decide which of the Cosy windows to use and for how long — but it won’t be able to modulate charge power or SOC dynamically minute by minute on Growatt hardware.
So, if you create a 3-hour slot in each cheap period, Wonder Watt may still only command charging for part of that time if its optimiser is enabled and your inverter supports it.
Otherwise, it will simply tell the battery: “charge during these windows” — and your inverter will charge until it hits 100 % SOC or the window ends.
🧮 3️⃣ What you should do right now
Given your setup and goal (automation, minimal micro-management), do this:
Create full-length windows in Wonder Watt that match all Cosy cheap periods:
00:00 – 04:00
13:00 – 16:00
(Check your current Octopus Cosy schedule in case it’s slightly shifted.)
Enable Smart Optimisation if your Wonder Watt account shows it (Settings → Optimisation → “Tariff Optimiser” or “Smart Charging”).
If it says “Growatt not yet fully supported”, leave optimisation off and keep the fixed schedule.
Watch the Wonder Watt logs for a few days.
If you see it varying the start/end times, you know it’s applying optimisation logic.
If not, it’s running in fixed-schedule mode, and you can shorten the slots manually if you prefer (e.g., 30–60 minutes).
📊 4️⃣ Coming soon (useful to know)
Wonder Watt is actively working on improved Growatt API control (source: Wonder Watt community forum, 2025 Q1 roadmap).
Once that’s live, it will handle SOC-based dynamic charging fully automatically — exactly what you want.
