The regulation does not differentiate between 'standardised' and 'non-standardised' spare parts. The obligation applies to all types of spare parts concerned. Since in this regulation, batteries are specified in the list of spare parts to be made available by manufacturers, they must be provided as such.
Disclaimer: Please note that the European Commission cannot provide a legally binding interpretation of the EU legislation, as this is the sole competence of the European Court of Justice. Any remarks from the European Commission services are without prejudice to the position the Commission might take should related cases arise in a procedure before the Court of Justice.