Battery Charge Time Calculator: How to Calculate Battery Charging Time

If you are using a battery backup to charge appliances, you might be looking for ways to extend its life. A rough random charging can influence the battery life. One way to protect the battery is by using a battery charge time calculator or some general formulas. This will help you understand how long it will take to charge your battery.

Jackery Explorer Power Stations are designed to be recharged faster using three different methods: solar panels, AC outlet, and carport. One popular battery backup is Jackery Explorer 2000 Pro Portable Power Station. It has a battery capacity of 2160Wh that can be recharged in only 2 hours, all thanks to its quick AC charging.

Jackery Explorer 2000 Pro Portable Power Station
- Quick charging in 2 hours via an AC wall outlet - Features a large battery capacity of 2160Wh - First-rate lithium battery for safe and reliable charging - Advanced smart screen to display 18 kinds of working states - Efficiently supports charging 96% of your home or outdoor appliances

Method 1: How to Calculate Battery Charging Time in Electrical Units

The battery charging time means the time taken to fully charge the battery of a portable power station or solar generator. It is crucial to understand how long the battery can charge appliances.

Charging Time = Battery Capacity ÷ Charge Current

Most often, the battery capacity is rated in amp hours (Ah), and the charge current is in amps (A).

Charge Time = Battery Capacity (Ah) ÷ Charge Current (A)

If the battery capacity is expressed in milliamp hours (mAh), watt hours (Wh), or kilowatt hours (kWh), you can follow the below formulas.

Charge Time = Battery Capacity (mAh) ÷ Charge Current (mA)

Charge Time = Battery Capacity (Wh) ÷ Charge Current (W)

If the units are mismatched, you'll have to use the conversion formulas.

Some conversion formulas are:

Watt hours = Amp hours × Volts

Milliamp hours = Amp hours × 1000

While this battery charge time calculator formula is simple, it is the least accurate.

Example: Suppose the battery capacity is 200Ah, and the charging current is 20 amps. In this case, the battery charge time will be:

Charge Time = 200Ah ÷ 20A = 10H.

Method 2: How to Calculate Battery Charging Time with Different Types

The battery charging efficiency is the ratio between the energy consumed by the charging process and saved battery energy.

For instance, if the device consumes 10,77kWh and the battery saves around 9,62kWh of that energy. This means the energy loss is approximately 11%, and 89% of the energy is held in the power station. 

Here is the battery charge time calculation method by taking charge efficiency into account.

Charge Time = Battery Capacity ÷ (Charge Current × Charge Efficiency)

One important thing to keep in mind is the type of rechargeable battery.

Lithium-ion: It is one of the commonly used battery types that offer the highest energy density and can store more energy. It has an efficiency of 90-95% and can last longer than other types.

Lead Acid: These rechargeable batteries have an efficiency of 80-85%. They are less expensive compared to lithium-ion and have a shorter lifespan.

NiCd: Nickel-cadmium is a popular type of battery for toys, flashlights, and digital cameras. They have an efficiency of 70-85% and have low internal resistance.

NiMH: They are high-density batteries but can only be recharged about 500 times. Like NiCd, NiMh batteries have an efficiency of 70-85% and work at full capacity until discharged.

Example: Let's calculate the charging time of a lithium-ion battery having 3000mAh, 24W charging rate, 12V voltage, and 90% charging efficiency using a 12V battery charge time calculator.

First, you'll need to convert the charging current (24W) into amps.

Amps = 24W ÷ 12V = 2A

Similarly, convert the battery capacity from mAh to Ah.

Ah = 3000mAh ÷1000= 3Ah

Charge Time = 3Ah ÷ (2A × 90%) = 1.67H

Method 3: How to Calculate Battery Charging Time with Charging Current

Charging current means the amount of current flowing into the battery when it is being charged or discharged. It depends on battery size, chemistry, and the charging method.

A battery's C rating means the rate of time that it takes to charge or discharge. The C rating is generally denoted by numbers like C5, C10, and so on, where C is capacity, and the number is time (usually represented in hours).

I (Current in amps) = Ah (Battery rating) ÷ C# (in Hours)

Example: Suppose you have a battery of 200Ah with a C10 rating. The charging current can be calculated by substituting the values.

Charging Current = 200Ah ÷ 10H = 20A

Method 4: How to Calculate Battery Charging Time with DoD

The battery's depth of discharge and battery discharge are the two terms you'll need to consider while calculating the charging time.

Depth of discharge is generally defined as the capacity discharged from a fully charged battery, divided by nominal battery capacity. In other words, DoD indicates the discharged battery percentage relative to overall battery capacity.

Battery discharge means the battery capacity in amp-hours (Ah) divided by the hours it takes to charge/discharge it. You can calculate the charge time of a battery concerning DoD using the below formula.

Charge Time = (Battery Capacity × Depth of Discharge) ÷ (Charge Current × Charge Efficiency)

Example: Let's say you want to calculate the charge time of a 100Ah lead acid battery with a 50% DoD. The charging efficiency of the lead acid battery with a 10A charging current is 80%.

Charge Time = (100Ah × 50%) ÷ (10A × 80%) = 50Ah ÷ 8A = 6.25H

Jackery Portable Power Stations Explained

Jackery is a renowned manufacturer of superior-quality solar products, such as solar panels, power stations, and solar generators. Jackery Explorer Portable Power Stations are battery-powered inverter generators that feature multiple ports to charge appliances.

These battery backups are equipped with lithium-ion batteries known for their long lifespan and durability. You can recharge these batteries using Jackery SolarSaga Solar Panels, wall outlets, and carports in a few hours.

You can calculate the working hours of the Jackery Explorer Portable Power Stations using the below formula.

Working Time = (Capacity in Wh × 0.85) ÷ Operating wattage of the device

We assume you are using a Jackery Explorer 2000 Pro Power Station with a battery capacity of 2160Wh to charge 500W appliances.

Working Time = 2160Wh ×0.85/ 500W = 3.6H

Below we reveal popular Jackery Explorer Portable Power Stations with their features and recharging time.

Jackery Explorer 300 Power Station

Featuring a compact-size battery capacity of 293Wh, the Jackery Explorer 300 can charge small appliances efficiently. It offers a super-fast recharge time of 2.5 hours by using the combination of a 60W USB-C PD charger and a 90W wall charger. The lithium-ion battery features a pure sine wave inverter and in-built BMS technology to power sensitive devices safely.

Recharging Time

• AC Adapter: 4.5Hours
• Car Adapter(12V): 5 Hours
• 1 x SolarSaga 100W Solar Panel: 5 Hours
• USB-C PD: 5.5 Hours

Customer Review

"This is a must-have device for situations/emergencies where you lose electricity. It's strong enough to power a CPAP machine overnight. Very high quality and reliable. Highly recommended." — Lasertron 9000.

Jackery Explorer 1000 Pro Power Station

Jackery Explorer 1000 Pro has a battery capacity 1002Wh that can support 93% of appliances efficiently. The solar charging power solution includes a pure sine wave inverter, industry-grade BMS, a foldable handle, and 94V–0 fire rating material. The pass-through charging feature ensures you can use all your devices while solar charging.

Recharging Time

• AC Adapter: 1.8 Hours
• Car Adapter (12V): 5.44 Hours
• 4 x SolarSaga 200W Solar Panel: 1.8 Hours
• 2 x SolarSaga 80W Solar Panel: 9 Hours

Customer Review

"I purchased this power station after Hurricane Ian and lost power for 3 days. This power station is the perfect answer for emergency power that can be used inside during a storm. I am comforted that I will be prepared if and when another Hurricane or storm comes to Florida." — FL Girl.

Jackery Explorer 2000 Pro Power Station

Jackery Explorer 2000 Pro can charge up to 8 electrical appliances simultaneously. It has a battery capacity of 2160Wh and 2200W output power to power 96% of your home or outdoor appliances. It is best known for quick charging in 2 hours via AC input. It's ideal for home backup power, off-grid living, and long RV or camping trips.

Recharging Time

• AC Adapter: 2 Hours
• Car Adapter (12V): 24 Hours
• 6 x SolarSaga 200W Solar Panel: 2.5 Hours
• 4 x SolarSaga 200W Solar Panel: 4 Hours
• 2 x SolarSaga 200W Solar Panel: 7.5 Hours
• 1 x SolarSaga 200W Solar Panel: 14.5 Hours

Customer Review

"Great for short-term home backup and for camping/tailgating. I keep mine charged as a battery backup for essential home appliances and have used it while tailgating to keep a heater and hotpot going. The draw from the heater was strong but maintained power for the hour I needed it." — DJ.

Battery Charge Time Calculator FAQs

What will affect the battery charging time?

Multiple factors, such as battery state, battery capacity, solar panel quality, and solar charge controller efficiency, can affect the battery charging time.

The below table reveals the average time it takes to charge an electric vehicle battery using different chargers.

How long does it take to charge a 100Ah battery with a 20 amp charger?

To calculate the charging time of the battery, you can use the following formula

Charging Time = Battery Capacity ÷ Charging Current = 100Ah ÷ 20A = 5H

However, it's worth noting that the actual charging time varies depending on the battery type, efficiency, etc.

How long should I charge a completely dead battery?

A dead battery means that it's fully discharged and the voltage is below 12V. In other words, a dead battery means no charge is left to charge the appliances.

Recharging a dead battery can take somewhere between 4 hours to 24 hours, depending on its type, size, etc. You can use the battery charge time calculator to find the time required to fully charge the dead battery.

Final Thoughts

If you use a battery backup for a home or a solar generator for off-grid living, using a battery charge time calculator is essential. This will help you calculate the charging time of the battery and protect power stations from undercharging or overcharging.

Jackery Explorer Power Stations are designed for faster charging and recharging. These robust and portable battery backup solutions can be recharged using solar panels, carport, or AC outlets. Once fully charged, you can use the power station to supply stable electricity to your home or outdoor appliances.