There is a certain text by the name of Agastya Samhita, the manuscript of which is now preserved in the Indian Princes’ Library at Ujjain. The manuscript dated 1550 as per the Shaka Samvat was owned by one Mr. Damodar Joshi and found by one Krishnaji Vajhe (Vaze) during his search for Indian scientific scriptures. It was given to the Sanskrit Department in Nagpur for translation, which was carried out successfully by Dr. Sahasrabuddhe.
In order to carry out the experiment, the head of Engineering in Nagpur, Mr. P. P. Hole was called. After obtaining the aid of an Ayurvedic doctor (regarding copper sulphate) the experiment yielded a voltage of 1.138 volts and a circuit current of 23 mili Ampere (mA).
One Australian by the name of Andrew Tomas, the author of a book known as ‘We Are Not the First, published in 1971 says that during his travels in india, he was informed of this manuscript which contains some methods for making electrical batteries.
The manuscript remains unpublished, but there are some famous verses from it available all over the internet, which I’m reproducing-
संस्थाप्य मृण्मये पात्रे ताम्रपत्रं सुसंस्कृतम्।
छादयेच्छिखिग्रीवेन चार्दाभिः काष्ठापांसुभिः॥
दस्तालोष्टो निधात्वयः पारदाच्छादितस्ततः।
संयोगाज्जायते तेजो मित्रावरुणसंज्ञितम्॥
Placing a well-cleaned copper plate in an earthen vessel, it should be covered by copper sulfate and then by moist sawdust. After that, put a mercury-amalgamated zinc sheet on top of the sawdust. The contact will produce an energy known by the name of Mitravaruna.
अनेन जलभङ्गोस्ति प्राणोदानेषु वायुषु।
एवं शतानां कुम्भानां संयोगकार्यकृत्स्मृतः॥
Using such energy/current of a 100 such pots, water will be split into Pranavayu (oxygen) and Udanavayu (hydrogen).
It is said that this Samhita also contains an account of using electricity for electroplating. Based on the Samhita, Mr. Vajhe also found different types of electricity based on the manner of generation, like Tadit, Hridani, etc.