"Serial numbers of battery and memory are crucial parts of an Electronic Voting Machine and should have been provided, as it was a specific request and these were very much available with the EC," she said in letter to Chief Election Commissioner Nasim Zaidi on Saturday.
She said: "We fail to understand why the data was not provided to use despite its availability."
Ms Chavan said: "A letter dated May 30 from the Election Commission for the first time mentions that we are required to choose an EVM out of a total of 14 randomly selected EVMs used in different polling booths during assembly elections for use in the EVM challenge.
"This is much contrary to an earlier understanding that we have to choose four EVMs and take up the challenge with the same," she added.
In response, Mr Zaidi said: "We have had detailed discussions with them for long hours. The Commission, keeping in mind the transparency of the process, has also offered them to open the EVM and take out memory and battery number and participate in the academic exercise and the challenge.
"We have offered them to come back again. I don't want to comment any further on what they said."
NCP also put eight questions to the EC, seeking to know who wrote the EVMs source code; who burns source code on the motherboard -- whether Indian or foreign company; what is the guarantee and the security measures to ensure source code has not and cannot be compromised; which companies service EVMs; names of transport companies engaged by Election Commission/State Election Commission/state governments at various stages for EVM transportation; who writes code for each assembly/Parliament segment; and audit protocol vis-a-vis security and EVM functioning etc.
The Election Commission told the NCP that as for change in protocol for choice of EVMs at the last minute was concerned, choice of additional three EVMs were sought only as a backup in case the first chosen EVM is inoperative as a result of transportation/handling by challenger.
"Since you had not given any specific polling station number for your choice of EVMs the Commission decided to randomly pick up EVMs from 14 polling stations to provide you a reasonable number of EVMs for final selection of one EVM during the challenge," it said.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)