If one battery system for an electric vehicle, EV or hybrid, HEV is good, then two is even better.
The gist, it seems more and more we are moving towards integrating two sorts of battery systems in EVs and different forms of HEVs. And it makes plenty of sense. While Lithium might be good due to its relative light weight and energy versus weight ratio, it is also expensive and prices haven’t come down nearly as much as they should have. Ultracapacitors, on the other hand are far better for quick bursts of energy, making them a perfect candidate for EV accelerations.
Hybrid Batteries. We have already looked at using two sorts of batteries, as in the case of AFS Trinity’s XH-150 using lithium and ultracapacitors and there are other alternatives. According to Technologyreview using lead acid batteries with ultracapacitors would make sense, especially for economical cars. Sounds familiar? John Petersen, at Seeking Alpha has been a long time proponent of lead acid batteries in a hybrid configuration. Even if they are heavier and not as efficient as lithium, they are cheaper and certainly would make for affordable EVs.
An Indiana company based in Noblesville called Indy Power Systems claims to have developed an energy control system for EVs and HEVs that would allow them to switch on the fly between two or more energy sources, even when their voltages are different.
The idea is to minimize stress on either package. The less they are used, the longer they can run. In AFS Trinity’s case, their claim is 180,000 miles for their battery package.