Turn Laptop Battery to a Power Bank

Question

Is it possible to turn a laptop battery into a power bank?

I have seen video tutorials and articles on how to turn AA Batteries into power banks, however, no one has created a power bank using a laptop battery. Is it possible? Will it shorten considerably the battery life of the laptop battery?

I want to turn a laptop battery to a power bank, and when all of the power of the battery drains, charge it by inserting the battery back to the laptop, and plug the laptop into a charger.

Will it be possible? And if it will, how?

Answer 1

It's not impossible, but there are some traps:

• first you have to decide whether you're going to open it up (voiding the warranty, slightly hazardous) or use it unmodified. If unmodified you have to find a matching connector which may be proprietary.

• Some batteries are "smart" and rely on a digital negotiation with the host laptop before turning on the power. See http://batteryuniversity.com/learn/article/how_to_repair_a_laptop_battery

• Lithium batteries are only good for a limited number of cycles. More use will wear them out more quickly.

Once you've addressed those the battery will put out usually 10-15V. A buck converter down to 5V will let you charge USB devices from it. However, realistically it's cheaper to buy a Chinese power pack designed for the purpose.