| > Knowing when the car is braking is trivial - the vast majority have a dedicated brake switch wire. Yes, that would work, provided it didn't affect the signal going to the vehicle's own computer. (It doesn't seem like it should, but I spent some time as an automotive engineer, and one thing I observed is that the car will do lots of things you don't expect.) [Edit: after seeing another comment below I'm not sure the switch would be enough; you need to know how hard the brake pedal is being pressed so you know how much braking the driver is requesting and can adjust the amount of regen accordingly. But there are ways to do that as well, as the commenter notes.] > Why do you want to prevent the normal brakes from engaging when regen braking is happening? Because the normal brakes prevent regenerative braking (regen) from happening. Both processes convert the vehicle's kinetic energy into something else--regen into electricity, normal braking into heat. You can't convert the same kinetic energy into two things at once, so any energy converted into heat by normal braking is unavailable for regen. > The majority of braking needs to happen up front due to dynamic weight transfer. Which will limit how much regen you can get, since it can only withdraw energy if it is actually slowing the wheel down. It may still be worthwhile to do regen, but not nearly as much as if you could do it on all four wheels. > Instead, use a simple brake balance controllers to reduce the mechanic braking effort at the rear and make up for it with the regenerative braking. Are these controllers dynamic? That is, can they adjust the balance depending on whether regen is happening or not? There will be circumstances when regen can't happen, or can't take all of the energy available (for example, if the battery is close to full or unable to accept charge fast enough). If the controllers are dynamic, then I agree you could put together a solution this way. But you would still need to do a lot of tuning of the controls. One thing I would be worried about if I were doing this is being able to get everything tuned smoothly without having access to the code and calibrations in the vehicle's own computers. |