Fork me on GitHub

Battery Size Calculator
Calculate the size battery you need for a certain runtime

Formula: Battery Ah - Watts of the load multiplied by the required runtime multiplied by the DoD devided by the desired battery voltage multiplied by the efficiency of the inverter.

If you have a 100 watts 42" TV and a 12V 7ah battery lying around and a UPS for example, then you can work out the runtime using the calculator below.

Reset Calculator

Time Conversion Table

Hours Minutes Total Minutes
1 0 60
1 30 90
2 0 120
2 30 150
3 0 180
3 30 210
4 0 240
4 30 270
5 0 300
5 30 330
6 0 360
6 30 390

Additional information about the calculator

The calculator will show you both Lithium and Lead Acid battery options.

The calculator automatically sets the optimal depth of discharge (DoD) depending on the load and battery type. To prolong the life of a battery, a lead-acid battery should not frequently be discharged below 70%, and Lithium-ion battery not below 20%. Note that 0% is a flat battery and 100% is a full battery.

How do I calculate the charging time of a battery?

If we ignore the losses during charging, divide the battery capacity by the charging current to obtain the battery's charging time in hours.

For example to charge a 100Ah Lead Acid battery using a 5Ah Optimate 6 charger will take roughly ±16 hours to recharge

Some articles you might also be interested in...

The tools, habits, and hardware needed to speed up your computer
The tools, habits, and hardware needed to speed up your computer

Whether it happens gradually over time or all of a sudden, trying to work with a slow computer can be seriously frustrating. Even if you’re fairly diligent with the maintenance of your laptop or PC, it’s surprising how quickly things slow down. If you are asking yourself “Why is my laptop so slow” and running Windows 10, 8, or 7, this post is for you!

Read The Article
An affordable VPN that also comes with a Geo Blocker
An affordable VPN that also comes with a Geo Blocker

The internet is full of restrictions, censorship, privacy invasions, security breaches, and a host of unwanted entities trafficking in your personal data. Using a VPN is a great first step toward protecting your privacy online. Privacy is fundamental to a well-functioning society because it allows norms, ethics, and laws to be safely discussed and challenged. Without privacy, a free and open society can neither flourish nor exist.

Read The Article
How to monitor the power usage of devices using a Sonoff Pow R2
How to monitor the power usage of devices using a Sonoff Pow R2

Sonoff Pow R2 is a 16A WiFi smart light switch that allows you to remotely manage and control your appliances and monitor your home energy usage. The WiFi light switch works like a power monitor, which allows you to keep track of 99% accurate real-time current, voltage and power on your app.

Read The Article