Not really, no.
The current copper clad zinc penny makes a fantastic (and dangerous) shorted cell battery, causing rapid boiling of its electrolyte! Don't let your toddlers swallow these pennies unless you like the idea of having them cook their stomach!
An old copper penny and an old silver dime used to be recommended for making experimental cells, but the modern ones don't work well.
No, because they are the same conductor and do not make a "ramp" for the electrodes to move along. They need to be different in order to make the electrodes move.
A short in the wiring.
If you are using it to turn on the car a good battery would help.
Yes and no. If the peanuts are moist, not dried, they will act an electrolyte between two dissimilar metal electrodes - zinc and copper for instance - and form a cell that would power a low-volt lamp. The peanuts would be best if ground into a paste to ensure good contact and a continuous path between electrodes. The is also possible with something like a whole apple or potato as well, just push the electrodes in, but what is really powering the lamp are the chemical reactions at the electrodes.
that means the battery is not good
Nothing good!
If the alternator is good and the battery does not charge, then the battery may be bad. There could be problem with the electronics. You will need to take it to a place where they sell batteries. They have equipment to check out the battery and the wiring.
Battery backup systems would be great in the event of power failures and outages. They would also be good to have if your main battery happens to die suddenly.
Any battery can be a good battery. The Walmart battery is an excellent battery at a good price. Know that Walmart does not manufacture batteries and it is made by one of the 4 manufactures in the U.S. The best battery would be an Optima but they are pricey.
A handbook on coins is a good guideline but all coin collectors say that a coin is only worth what someone would pay for it.
Metals are good for batteries because they can easily release and accept electrons, allowing for efficient energy transfer. Saltwater is a good electrolyte because it allows ions to flow between the electrodes, facilitating the chemical reactions that generate electricity in a battery.
Take them to a coin dealer for an appraisal. It would be a good idea to borrow a price guide (the Blackbook or Guide to US Coins for US coins) from the library and try to separate the 'good stuff' from the 'junk' first.