DoD vs SoC: What They Mean for Your Solar Battery Health
- Maria Suerte
- Oct 25
- 2 min read
Understanding DoD and SoC — The Basics
When you start exploring solar battery systems, you’ll come across two key terms: DoD (Depth of Discharge) and SoC (State of Charge).
They might sound technical, but they’re actually two sides of the same coin — showing how much of your battery is used versus how much is left.
Let’s break it down in simple terms.
What is DoD (Depth of Discharge)?
DoD means how much of your battery’s capacity you’ve already used.
Think of your battery like a water tank — DoD is how much water you’ve taken out.
Example: If your battery has 10 kWh capacity and you’ve used 6 kWh, then your DoD is 60%.
The higher your DoD, the more of your battery you’re using — and that affects its lifespan over time.
What is SoC (State of Charge)?
SoC means how much charge your battery still has left.
Using the same water tank example — SoC is how full it is right now.
Example: If your DoD is 60%, then your SoC is 40%. That means 40% of your battery’s energy is still available for use.
Quick Analogy
Concept | Meaning | Example |
DoD (Depth of Discharge) | How much you’ve used | 70% DoD = 70% battery used |
SoC (State of Charge) | How much remains | 30% SoC = 30% battery left |
They always add up to 100%.
Why DoD and SoC Matter
Understanding DoD and SoC is crucial for managing your battery’s performance and lifespan:
Battery Life: The deeper you discharge (high DoD), the faster the battery wears out.
Performance: Most modern lithium batteries allow 80–90% DoD safely.
Backup Power: Knowing your SoC helps you see how much energy remains during a blackout.
For example, if your solar battery’s DoD limit is 90%, it means you can use up to 90% of its total capacity without damaging it.
Example in Real Use
Let’s say you have a 10 kWh battery with 90% usable DoD. That means you can safely use 9 kWh every night before it needs recharging.
When it recharges to full during the day, your SoC returns to 100%. Over time, this cycle repeats — and managing it well ensures your battery lasts longer.
How SolarMatch AU Helps
At SolarMatch AU, we make it simple to compare solar batteries by: - Showing usable kWh capacity (not just total size) - Explaining DoD and SoC clearly in each quote - Matching you with installers who use CEC-approved batteries with reliable warranties
No jargon. No confusion. Just clear comparisons so you can pick the right system for your home.
Final Thoughts
DoD = how much you used.
SoC = how full it is now.
Understanding these two terms helps you make smarter choices, maintain your battery health, and maximize your solar savings.
Ready to Compare Solar Battery Options?
Get up to 3 expert quotes from vetted installers — fair, transparent, and all for just $20. Visit SolarMatchAU.com to start your solar journey today.
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