Battery Calculators

Battery Runtime Calculator

Calculate how long your battery will last under any load. Enter capacity, voltage, and wattage for an instant runtime estimate.

Propane Generator Run Time Calculator

Calculate how long a propane generator runs on a given tank size. Enter tank weight, load, and generator efficiency.

12V Battery Runtime Calculator

Calculate how long a 12 volt battery lasts under any load. Pre-tuned for 12V deep cycle, AGM, and LiFePO4 systems.

LiFePO4 Battery Runtime Calculator

Estimate LiFePO4 battery runtime with accurate DoD and efficiency defaults. Compare lithium iron phosphate vs lead-acid.

Portable Power Bank Runtime Calculator

Find how long your portable power bank charges your phone, tablet, or laptop. Enter mAh, voltage, and device wattage.

Battery Charge Time Calculator

Calculate how long it takes to charge any battery. Enter capacity, charge current, and DoD for accurate charge time.

Battery Charge and Discharge Calculator

Calculate both charge and discharge times for your battery in one place. Model a complete daily battery cycle.

Cold Cranking Amps (CCA) Calculator

Calculate CCA requirements for your vehicle based on engine size, type, and climate. Find the right starting battery.

Battery Size for Inverter Calculator

Find the right battery capacity for your inverter. Enter load, runtime, and voltage for a proper battery sizing estimate.

How Long Will a 12V Battery Run a Refrigerator?

Calculate how long a 12V battery powers your refrigerator. Works for power outages, camping, and off-grid setups.

Deep Cycle Battery Runtime Calculator

Estimate deep cycle battery runtime for marine, RV, and off-grid use. Accounts for depth of discharge and Peukert losses.

Battery Capacity (Amp Hours) Calculator

Calculate battery capacity in amp-hours from watt-hours and voltage. Convert between Wh, Ah, and watts easily.

UPS Battery Backup Time Calculator

Calculate how long your UPS keeps devices running during an outage. Enter VA rating, load, and battery capacity.

Laptop Battery Runtime Calculator

Estimate your laptop battery life based on battery Wh rating and actual power consumption by usage mode.

RV Battery Runtime Calculator

Calculate how long your RV battery bank powers your camper. Enter your loads, battery size, and get real runtime.

Marine Battery Runtime Calculator

Estimate trolling motor and boat electronics runtime from your marine battery. Built for anglers and boaters.

Car Battery Runtime Calculator

Calculate how long a car battery powers accessories with the engine off. Know the limits before you drain your starter.

Reserve Capacity to Amp Hours

Convert battery reserve capacity (RC minutes) to amp-hours. Understand what RC means and how it compares to Ah.

Watt Hours to Amp Hours Calculator

Convert watt-hours to amp-hours at any voltage. Essential for comparing batteries rated in different units.

Battery Voltage to Percentage Calculator

Convert battery resting voltage to state of charge percentage. Charts for lead-acid, AGM, and LiFePO4 at 12V, 24V, 48V.

How Many Watts in a 12V Battery?

Calculate total watt-hours stored in any 12V battery from its amp-hour rating. Includes common 12V battery examples.

Lead-Acid Battery Runtime Calculator

Calculate lead-acid battery runtime with Peukert effect awareness. Compare flooded vs sealed types for real-world runtime.

AGM Battery Runtime Calculator

Estimate AGM battery discharge time with chemistry-specific defaults. Compare AGM vs flooded lead-acid for your use case.

How Long to Charge a 100Ah Battery?

Calculate charge time for a 100Ah battery from any source: solar, charger, alternator, or generator. Real-world estimates.

Battery Pack Calculator

Size a custom battery pack using series and parallel cell configurations. Enter target voltage, capacity, and cell specs.