Reuse of Laptop batteries

Project duration 05/2019 - Today
Status Active
Battery type reused Laptop batteries
Location Karnataka (India)
Pilot partners Audi Environmental Foundation, Nunam, Selco Foundaton, Karnataka Forest Department
Contact people Darshan Virupaksha, Nunam (

Project description
In 2017, Nunam started (as a DIY project) experimenting with used Smartphone and Laptop batteries in India – trying to understand if there might be remaining life left over. The answer surprisingly positive, with state of health levels on average of 65%. With the support of the Audi Environmental Foundation, Nunam was able to expand on this idea with a new project starting mid of 2019 with the goal of deploying prototypes with used laptop batteries and implementing them in India with users who need energy storage systems for their livelihood (primarily LED lighting and phone charging). The devices are IoT enabled with a simple android companion app.

In this project, Nunam has implemented 15x energy storage systems that run completely on used Lithium-ion battery cells from old Laptops batteries. These were sourced randomly from electronic waste dealers in India. They have been dismantled, tested, grouped in Bangalore. The local pilot implementation partners are Selco Foundation and the Karnataka Forest Department . The use cases of these prototypes with an average capacity of 0.25 kWh are LED lighting (5W) and phone charging. More context can also be found here .

With the support of the Audi Environmental Foundation, Nunam was also able to deploy one prototype with used electric vehicle batteries from the Audi e-tron for a solar nanogrid in Uttar Pradesh, India. More details of this project can be found here.

Laptop battery prototypes

Number of systems deployed


Total battery weight reused

18.6 Kg

Total battery capacity used

3.13 kWh

Total Co2 avoided by reuse

156 Kg

Dashboards & Data


What went well?

The battery pack degradation so far seems “normal” as of now since it is early days of the packs; we have not seen any unexpected capacity drops. All the deployed packs are delivering power as expected. Our pilot users liked the combination of a powerful 5W bulb and a mobile charger. The portability due to its light weight and 15+ hours of continuous operation were a major boost to the adoption. Especially in the forest regions during night patrol or while tackling animal intrusion into human habitats at night. Charging process was smooth with adequate sunshine available most parts of the year.

What didn't go well?

The trade off to have our (good looking) 3D printed casing against e.g. standard ABS plastic boxes proved to be operationally expensive since users often dropped the case, it was too fragile for their usage. Since some of the beneficiaries live in remote locations the telecom network is inconsistent, it caused challenges with data transmission and retrieval. Users are tending to add other loads to the PV system which results in insufficient capacity to charge Nunam devices, especially during the monsoon season.

Next Step?

We will continue studying the degradation patterns of the cell in the device and contribute the learnings to the community. Extrapolate learning into bigger second life packs based of cylindrical cells from other applications such as micro mobility scooters. The key challenge remains on finding ways to reuse cylindrical cells at scale and we hope to work with partners to solve the problem collaboratively.