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Battery Runtime Calculator

Lead, Li-Ion, LiFePO4 - with Reserve, Peukert Effect and Temperature

20%
Buffer that will never be discharged (e.g. for Lead: 20%)
25 °C
Estimated Runtime (with Peukert)
7h 0m
Einfach (ohne Peukert): 7h 0m
Usable Capacity
70,0 Ah
840,0 Wh
Total Capacity (nominal)
100,0 Ah
1.200,0 Wh
Effective Current
10,0 A
C-Rate: 0,10C
Temperaturkorrektur
0,0%
25°C → 100,0% Kapazität
Capacity Breakdown
Reserve (20%) Nutzbar Schutzzone (10%)
Kennwerte: Lithium-iron phosphate (LiFePO4)
90%
Max. DoD
97%
Wirkungsgrad
1.05
Peukert-Exp.
1%/Mo
Selbstentladung
Runtime at Various Currents (Peukert)
StromC-RateLaufzeit (Peukert)Laufzeit (ideal)
1,00 AC/1003d 6h 32m2d 22h 0m
2,00 AC/501d 13h 56m1d 11h 0m
5,00 AC/2014h 30m14h 0m
10,00 AC/107h 0m7h 0m
20,00 AC/53h 23m3h 30m
50,00 AC/21h 18m1h 24m
100,00 AC/10h 37m0h 42m

Accurate Battery Runtime Calculations

The tool provides precise estimates for how long your batteries will last under specific loads. By accounting for chemical differences between Lead-acid, Li-ion, and LiFePO4 chemistries, it calculates usable capacity accurately. It integrates critical factors like the Peukert effect for lead-acid systems, temperature variations, and reserve capacities to ensure you have a realistic view of your power supply before planning any off-grid or mobile energy installations.

Optimized Planning for Solar and RV Systems

Whether you are designing an off-grid solar setup, powering a marine vessel, or equipping an RV, knowing the exact runtime is crucial. The calculator helps you determine how much capacity you need to sustain your devices for specific durations. By inputting your load current and voltage, you can see a breakdown of how different discharge rates affect total runtime, helping you choose the right battery size and chemistry for your specific energy needs.

Privacy-Focused Browser Tool

Your data privacy is important. The Battery Life Calculator processes all calculations directly in your web browser. No personal information or technical specifications are sent to external servers or stored in a database. This ensures that your project details remain private while you perform complex calculations for your energy systems, making it a safe and reliable tool for both individual hobbyists and professional installers.

Frequently asked questions

How do I calculate the runtime of my lead-acid battery?

To calculate lead-acid battery runtime, you must consider the Peukert effect, which accounts for how higher discharge currents reduce actual capacity. Our tool automates this calculation by factoring in your specific load current, the battery's nominal capacity, and the required reserve capacity to provide a realistic estimate of available operating hours.

What is the difference between Li-ion and LiFePO4 for my project?

Li-ion batteries generally offer higher energy density while LiFePO4 provides more stability and longer cycle life. Our tool helps you compare these chemistries by calculating usable capacity and expected runtime based on their specific characteristics, such as the lack of a significant Peukert effect in lithium-based systems.

How does temperature affect my battery's performance?

Temperature significantly impacts chemical reactions within batteries. Cold temperatures can increase internal resistance, while high heat can accelerate degradation. The calculator includes an ambient temperature factor to adjust the expected runtime and capacity based on your specific operating environment, ensuring more accurate planning for outdoor or mobile applications.

What is Reserve Capacity in battery calculations?

Reserve capacity is the amount of energy kept in a battery to prevent deep discharge and prolong its lifespan. For lead-acid batteries, it is vital to keep a buffer, often 20 percent. Our tool allows you to set this percentage so you can calculate only the usable portion for your daily operations.