It is hard to say what the R
It is hard to say what the R&D and testing process will entail or cost, but updating their technology is key to staying competitive. Tesla had little real competition in the 1-2% niche market that was EVs for the last decade, but their successes in producing a selling EVs will be bringing in serious competition over the next 3-5 years from large automakers with vast engineering and manufacturing resources. Since Tesla is still in the process of building their Gigafactory in China, they could probably set up and test the new battery manufacturing facilities right there with little disruption in production. China sold over 1.2 million "New Energy" (PHEV/BEV) cars last year, so there is a big market there alone. The good choice in in buying Maxwell is that their ultra capacitor and dry electrode lithium battery technologies are already established, so the only work left is adapting their storage systems to Tesla's electric vehicles. Tesla demonstrated with their Model S that battery pack swaps are possible with existing cars in minutes because of their modular design, so it is quite possible that they are already testing the new battery systems in their cars right now.