Has anyone examined the health effects that the large magnetic fields of the current from/to the batteries has on the passengers? Charging during braking will cause a pulsating magnetic field, which may be even worse.
Just wear a tinfoil hat.
The fields would be there while you're discharging, too.
Of course, it's ironic that you're sitting in front of your computer filled with switch-mode power supplies and a monitor that uses magnetic fields to control the display not to mention the fields from the wiring in your house.
Actually, magnetic field strength drops off quickly with distance (move twice as far from the source and the strength drops by the cube, 1/8 as strong). Besides which, many materials are flux concentrators, so the magnetic lines of force pass through them and not the air.
In short, don't worry about it. If you do decide to take johnandrhonda's advice, make sure the hat is made from stainless steel, not aluminum or tin foil. Stainless steel underwear might help, too.
Junk "science"...