Exactly so Aorus. Additionally the more this virus is customized to build battery anodes and cathodes the less it will be able to successfully replicate without high concentrations of the needed building and binding materials it was designed to use. Your average bacteria isn't exactly loaded with iron and nickle-phosphate. 😉
The important part is that while they are trying to make intentional performance adjustments they can also run experiments to let the virus "adjust itself" and see which ones yield better results and why.
AKA they can take a batch of this virus, cause random point mutations, and then separate them out and put them in a battery building environment. Most will preform worse or similar to what they started with. But some mutations will be advantageous. Wash rinse repeat and continue selecting for the best performance. Not unlike breeding horses, let nature take care of some of the work.