If we produce all electric and hibrid cars, how will we dispose of the old batteries?

They will be recycled in the future the same way they are now. The acid can be neutralized with lime, and the lead can be used for making things like glass.

recharge them

and we can always recycle the battery when it is not useful as a battery anymore. Doug, I think the alternator is used to charge your car battery.

They can be recycled. That's true now, and it will be much more true in the future. The batteries will be specifically made to be recycled, every last bit. Even now, Toyota buys back the old batteries from the Prius and recycles them.

Of course, the batteries in hybrid and all-electric vehicles are rechargable. But every time they are recharged, they lose a bit of capacity. The same thing happens with your cell phone. After about 12-18 months, the battery lasts only about 50% as long as it did when it was new. Then it's time to get a new battery. The old battery can be recycled. Most batteries, whether rechargable or not, can be recycled. In California, it's illegal to throw away any battery. Thus, many stores have a battery recycling bin. Just drop them off when you go shopping. For larger batteries, like the ones in cars and boats, take them to a service center where they will be sent for recycling.

We've found ways of recycling and re-using many toxic materials in the past. I'm sure scientists will figure out a way to make use of all the dead batteries once they cannot hold a charge.

since car batteries are so big they should be recycled.

Never though about that...I agree with the 1st guy re-charge baby!

We will use ten times the energy saved during the lifetime of these cars just to process the waste including the batteries when the cars are dismantled. Hybrid cars are a plague on the planet and will do far more harm than good.