How Long Will A 60ah Battery Last? + Battery Runtime Calculator

12v 60Ah lead-acid battery with a 50% depth of discharge limit will last anywhere between 36 hours (running a 10W appliance) to 3.2 hours (running a 100W appliance)

Long Answer: 60Ah battery backup time will depend on these factors

  • Battery Type
  • Battery Voltage
  • Inverter Efficiency
  • Output load

So in this guide, i’ll try to explain every aspect so that you can calculate the exact estimated runtime of your 60Ah battery

Need an easy solution? use my free calculator (given below) to find out the battery runtime. Enter battery specs and the total connected load.

Battery Runtime Calculator

Battery Capacity
Ah
Battery Volts
V
Select Battery Type
Load Connected with inverter?
Total Load (watts)
Wh

Assumptions

  • Lead-acid Battery: 50% depth of discharge limit (DoD)
  • AGM Battery: 50% depth of discharge limit (DoD)
  • Lithium Battery: 100% depth of discharge limit (DoD)
  • Inverter Efficiency Rate: 90%

Example

Let’s suppose you have a 12v 60Ah lead-acid battery and a medium size camping fridge that consumes about 60 watts of power per hour and a 500w inverter with a 90% efficiency rate

12v 60ah lead-acid battery will last about 5.1 hours while running a medium size camping fridge with a 90% efficient inverter

Introduction To Batteries (Type, DoD, Amp, Voltage, C-rating)

If you’re a newbie you should know the basics of the batteries which will determine the backup time of your battery.

Car vs Deep Cycle Battery

Car batteries are designed to produce a burst of power that is used to start the car or vehicle.

Deep Cycle batteries are designed to be discharged to draw the power at a lower yet constant rate.

using a car battery to run your appliances is not a good option. If you do it consistently for a period of time it will decrease the lifespan of your car battery.

Amperage (Amp), Amp-hours (Ah), Voltage (V), Watts (W)

Here are a simple explanation of different electricity units which are used in batteries

  • Amperage (A): is the unit to describe the amount of current
  • Amp-hours (Ah): is the total amount of current which a battery can store
  • Voltage (V): is the amount of current which can pass in and out at a time 
  • Watts (W): is the total amount of power (Amps * Volts = Watts)

In simple words, Amp-hours is the total length of a pipe and the voltage is the width of a pipe.

Batteries capacity is measured in amp-hours (Ah) and the standard voltage is 12v, 24v, and 48v. 

A 24v battery can store more power than a 12v same-capacity battery. 

A 12v 60ah battery is equal to 720 watt-hours (Wh), 24v 60ah battery capacity = 1,440Wh or 1.44kWh, and 48v 60ah battery capacity = 2,880Wh or 2.88kWh

Related Post: Amps To Watts Calculator: How Many Watts In A 12-volt Battery?

Battery Type

Batteries are made of different chemical formulas which determine their depth of discharge limit, The most common ones are Lead-acid, Lithium-ion (LiFePO4), AGM, and gel batteries

Depth of discharge (DoD): is referred as how much battery you use in between charges (eg. 50% DoD = 50% half battery capacity is used, 80% DoD = 80% of battery capacity is being used) 

Only lithium or (LiFePO4) can be fully discharged up to 100% on the other hand most of the other battery types have their DoD limit of 40-50% which means you can only use 50-60% of their storage capacity

Discharging your battery to 100% depth of discharge will damage the battery internal cells which as a result will decrease the battery lifespan and in some cases, you won’t be able to restore the charge to your battery

C-Ratings

Battery C-rating is the measurement of the current in which a battery is charged or discharged. 

The c-ratings of a car battery will be higher because of their built-in design, but on the other hand, deep cycle batteries are designed to be discharged at a lower yet continuous rate. 

So discharging your deep cycle battery at a higher rate than what is recommended will increase the battery’s internal temperature which as a result will cause wattage loss in the battery and will decrease the battery backup time. 

Lead-acid, AGM, & GEL batteries usually have C-ratings of 0.2C, But lithium or Lifeop4 batteries can be discharged at a rate of 1C (1C= 1 hour)

C-RatingTime
1C1 Hour
2C30 Minutes
5C12 Minutes
0.5C or C/22 Hours
0.2C or C/55 Hours
0.1C or C/1010 Hours
0.05C or C/2020 Hours
Table: C-rating & service times when charging and discharging your battery

This means you can discharge your 60ah lithium battery in one hour without causing any power losses but if you have a lead-acid type battery it is recommended to be discharged in 5 hours (12 amps per hour) 

Note! Check the exact C-ratings of your battery read the battery specs sheet or it will be mentioned on the battery it self or you can ask the manufecturer about the battery c-ratings of yours 

Inverter Efficiency (DC vs AC watts) 

Batteries store power in DC (direct current) but most of our household appliances required AC (alternating current) 

So to convert DC into AC use inverters and again inverters are not 100% efficient, which means there will be power loss when converting DC into DC

Most of the inverters are about 90% efficient, which will consume 100 DC watts from the battery to run a 90 AC watt appliance. 

Note! To check the exact efficiency rate of your inverter read the product description part or just assume a 90% efficiency rate which is the most common one. 

Also choosing the right size cable for your battery and inverter is also important to minimize power losses, i have made a chart for you that you can use to find out the size of cable for your inverter (read the below-mentioned post)

Related Post: Solar DC Watts To AC Watts Calculator 

60ah Battery Backup Time: Calculation 

Now with the help of the factors which i have explained to you earlier let’s calculate how long your battery will last on a load. 

Let’s assume you have a 12v 60ah lead-acid battery (50% DoD limit) and is fully charged, so how long it will last while running a 50-watt of AC load? 

12 * 60 = 720Wh
720 * 0.5 (DoD limit) = 360Wh (DC)
360 * 0.9 (inverter efficiency) = 320Wh (AC) 
320/50 = 6.4 hours 

Your 12 60ah battery with 50% depth of discharge will last about 6.4 hours while running a 50 watts of output AC load with a 90% efficient inverter. 

Note! If you have a lead-acid battery you can only draw 144 watts of power from your 12v 60ah capacity battery with a c-ratings of 5 hours (0.2C or C/5) and 720 watts of power at a time from a 12v 60ah lithium battery. 

How Long Will A 60ah Battery Last? – Chart

Here’s a chart on how long will a 12v 60ah lead-acid and lithium battery will last while running different appliances

Appliance Rated WattageEst. Runtime on 12v 60ah lead-acid batteryEst. Runtime on 12v 60ah Lithium battery
Fridge 130 watts2.5 hrs5 hrs
TV50 watts6 hrs12 hrs
LED Bulb20 watts15 hrs30 hrs
Computer 300 watts1 hrs2 hrs
Air purifier25 watts 12 hrs24 hrs
Ceiling Fan 60 watts5 hrs10 hrs
Electric Blanket200 watts1.5 hrs3 hrs
Chart: How long will a 60ah battery last (60ah battery backup time)

Summary

  • 12v 60ah lead-acid battery with a 50% Depth of discharge limit last about 2.5 hours while running a medium size new technology fridge and lithium (LiFePO4) battery will last about 5 hours with a 100% Depth of discharge limit
  • 12v 60ah lead-acid battery with a 50% Depth of discharge limit last about 6 hours while running a TV and lithium (LiFePO4) battery will last about 12 hours with a 100% Depth of discharge limit

To keep your battery fully charged you’d need the right size solar panel, to calculate what size solar panel you’d need to charge your 60ah battery use my free online calculator

Must Read: Solar Panel Calculator For Battery

Conclusion

short answer? use the calculator mentioned above to calculate the backup time of your battery

long answer? use this formula to calculate the runtime of your battery

Battery Runtime = Battery Capacity (Wh)/Output load (W)

Battery Capacity in Watt-hours = Battery Ah * battery Volts (V)

I hope this short guide was helpful to you. still, have any confusion? LEAVE A COMMENT or contact us. Thank You!

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I'm an experienced Sales Consultant with a demonstrated history of working in the renewables and environment industry. Skilled in Photography, Customer Service, and Sales.

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