What Do Battery Specifications Actually Mean?

What do all the solar battery specifications actually mean?  

Battery capacity—measured in kilowatt-hours—shows the raw amount of electricity a battery can hold, just like the size of a fuel tank. A 10 kWh unit could, in theory, power a 1 kW load for ten hours. 

• Typical households consume 18–20 kWh a day, but only your after-solar hours matter when sizing storage. 
• Most residential packs span 5–15 kWh, and modular systems such as Sigenergy’s SigenStor scale from 5 kWh up to 48 kWh in the same stack, giving future-proof flexibility —ideal if your family or EV fleet grows. 

Remember the distinction between nominal and usable capacity; usable is capped by the manufacturer-approved depth of discharge, explained next.

How much power can it deliver at once? (Power rating in kW) 

If capacity is the fuel tank, power rating is the engine’s horsepower. Continuous power indicates what the battery can supply indefinitely, while peak power covers short bursts for start-up surges— say, an air-conditioner’s compressor. 

A “10 kWh / 5 kW” unit delivers five kilowatts non-stop; its 7 kW peak might run for ten seconds. Batteries from Sungrow often pair generous continuous and peak figures, ensuring you can boil a kettle, run lights, and keep the fridge humming simultaneously. 

Match the rating to the heaviest load you plan to run during an outage or at night; undersizing leads to tripped circuits even if there is plenty of stored energy left. 

How much of that energy can you use? (Depth of discharge) 

Depth of discharge (DoD) is the percentage of stored energy you can draw before recharging without harming the battery. Most modern lithium-iron-phosphate (LFP) units advertise 90–100% DoD. A 10 kWh pack at 95 % DoD yields 9.5 kWh usable. 

Higher DoD equals more accessible energy and often lower lifetime cost, but cycling to the maximum every day can nibble away at lifespan. Stick to the manufacturer’s recommendation and enable any smart discharge limits available in the app or inverter menu. 

How long will it last? (Cycle life and throughput) 

Lithium batteries age by cycles—one full charge and discharge, or by total throughput.  A quality LFP model rates for 3,000–6,000 full cycles, translating to 10–15 years of daily use. Some makers, including Sigenergy, also warrant a fixed energy total (e.g., 30 MWh for a 10 kWh pack).  The warranty ends when years, cycles, or throughput is reached, whichever comes first. 

Tip: Partial cycles count proportionally—two half-discharges equal one cycle—so gentle use can extend practical life. 

How efficient is charging and discharging? (Round-trip efficiency) 

Round-trip efficiency is the fraction of energy you retrieve after charging losses. Modern lithium units hit 90–95 %. The SolarEdge Home Battery, for example, claims 94.5 %. Higher efficiency means more solar self-consumption and lower payback time because less power is wasted as heat. 

Can it cope with Australian conditions? (Operating temperature & IP rating) From Darwin’s wet heat to Canberra’s frosts, batteries face extremes. Check: 

• Operating temperature: Many systems charge happily from 0°C to 50°C and discharge down to –20°C or lower. Sungrow SBR specifies –30 °C to 50 °C; SigenStor stretches to  55 °C.
• Ingress Protection (IP): For outdoor installs, IP55 or IP65 is advisable. IP65 means dust-tight and protected against low-pressure water jets—ideal under an eave or on a garage wall. 

A well-ventilated, shaded spot expands lifespan and meets manufacturer warranty clauses; a CEC-accredited installer will guide positioning and may recommend a simple sunshade to reduce summer stress. 

What does the warranty really promise? 

A robust Australian solar battery warranty usually spans ten years and guarantees that, by the end, at least 60–80 % of the original usable capacity remains. Key points to confirm: 

1. Duration – 10, 12, or even 15 years on premium models. 
2. End-of-warranty capacity – commonly 70 %. 
3. Cycle life/throughput cap – e.g., 6,000 cycles or 30 MWh. 
4. Conditions – CEC-accredited installation, firmware updates, ambient temperatures within spec. 

These promises sit alongside your non-waivable rights under Australian Consumer Law. 

Bringing the numbers together 

When you read 10 kWh / 5 kW, 95 % DoD, 6,000 cycles, 94 % round-trip efficiency, –20 °C to 55  °C, IP65, 10-year warranty (70 % capacity) you now know: 

• You can draw up to 9.5 kWh before recharging. 
• Five kilowatts will run major appliances without brown-outs, and short peaks can tackle motor start-ups. 
• Daily cycling should see more than a decade of service before capacity falls to 7 kWh.
• Minimal energy is lost, maximising your solar harvest. 
• The system will shrug off harsh Australian weather if installed correctly. 

Add modularity—say, stackable 5 kWh blocks in Sigenergy’s design—and you also gain an upgrade path if electric vehicles or electric hot-water systems shift your load profile. 

Conclusion: Choose with confidence 

Mastering solar battery specifications empowers you to compare models on real merit, ask sharper questions, and avoid spending on features you will never use. Pair this knowledge with a site-specific load analysis, consider current state incentives such as NSW’s battery rebate or Victoria’s interest-free loans, and always engage a Clean Energy Council-accredited professional who follows  AS/NZS 5139 wiring rules.

For independent guidance and quotes from trusted installers, Your Energy Answers stands ready to help you unlock lower bills and a cleaner grid, without the jargon.