Battery Sizing Calculator

Our Battery Sizing Calculator is designed to help you determine the ideal battery capacity for your van conversion. By inputting your daily energy consumption, the number of days you want the battery to last without recharging (days of autonomy), the depth of discharge (DoD), and the battery voltage, the calculator will provide an accurate estimate of the required battery capacity in amp-hours (Ah).

​

Understanding Key Terms

Depth of Discharge (DoD): This refers to the percentage of the battery that can be used without causing damage. For instance, lithium batteries typically allow up to 80% DoD, while lead-acid batteries are usually limited to 50%. A higher DoD allows for more usable capacity but can reduce the overall lifespan if not managed properly.

Days of Autonomy: This is the number of days you want your battery to power your van without needing to be recharged. For off-grid living, it's crucial to factor in days with little to no sun, especially if you rely on solar panels. The more days of autonomy you require, the larger the battery capacity you'll need.

​

Formulas Used

The primary formula used in this calculator is:

 

Battery Capacity (Ah) = (Daily Energy Consumption (Wh) × Days of Autonomy) / (Battery Voltage (V) × Depth of Discharge (DoD))

 

This formula ensures that the battery capacity accounts for your energy needs over the specified period without recharging while considering the safe discharge level of the battery.

​

Why Accurate Battery Sizing Matters

Proper battery sizing is critical for ensuring your van can meet all your power needs without running out of energy. Undersized batteries may lead to power shortages, while oversized batteries could be a waste of space and money. With this calculator, you can tailor your battery size to your exact requirements, balancing cost, space, and energy needs.

​

Example Scenarios

Imagine you consume around 1500Wh per day and you want your van to be self-sufficient for at least 3 days without solar input. By inputting these values into the calculator, it will recommend a battery size that can comfortably meet this demand. For instance, the calculator might suggest a 450Ah battery at 12V, considering a 50% DoD if you choose a lead-acid battery.

​

Battery Types: Lead-Acid vs. Lithium

When choosing a battery, it's important to understand the differences between lead-acid and lithium options. Lithium batteries, while more expensive upfront, offer a higher DoD and longer lifespan, making them a more efficient choice for van conversions. Lead-acid batteries, on the other hand, are cheaper but bulkier and less efficient.

​

Common Mistakes to Avoid

One of the most common mistakes when sizing a battery is underestimating energy consumption. Be sure to accurately calculate your daily energy use, accounting for all devices you plan to power, from lights and refrigeration to charging devices. Another mistake is not considering the efficiency losses in the system; always add a buffer to your calculated capacity to ensure reliable performance.

​

Maintenance Tips for Longevity

Maintaining your battery is essential for prolonging its lifespan. For AGM batteries, avoid deep discharges. Lithium batteries require less maintenance but still benefit from being kept within optimal temperature ranges and avoiding extreme discharges.