Off-Grid Solar Battery Calculator: Don’t Buy the Wrong Bank (2026 Guide)
Off-Grid Solar Battery Calculator: Don’t Buy the Wrong Bank (2026 Guide)
It’s 2:00 AM. You are parked deep in the mountains. The temperature outside just hit freezing. Suddenly, your diesel heater beeps once and shuts off. The lights flicker and die. Total darkness.
Your battery monitor reads 10.5V. You are out of power.
This scenario happens to thousands of Van Lifers and Off-Grid enthusiasts every year. Why? Because they guessed. At ShockTrail, we calculate.
The ShockTrail Calculator
Input your loads below to see exactly what battery bank you need. This tool accounts for inverter efficiency and depth of discharge.
Why Most People Fail
The number one mistake is ignoring the Depth of Discharge (DoD). If you buy a 100Ah Lead Acid battery, you only have 50Ah usable. If you drain it to zero, you kill it. Lithium (LiFePO4) allows you to use 100% of the rated capacity.
Real World Sizing Examples
| User Profile | Daily Load | Recommended Bank |
|---|---|---|
| Weekend Warrior | Phone, LED Lights (~400Wh) | 1x 50Ah LiFePO4 |
| Van Lifer | Fridge, Laptop, Fan (~1200Wh) | 1x 200Ah LiFePO4 |
| Cabin / RV | Microwave, Starlink, TV (~3000Wh) | 2x 200Ah LiFePO4 (400Ah Total) |
Article written by the ShockTrail Engineering Team.
