First I asked Campbell where the the car batteries nowadays and if there are any problems car companies face with today's batteries.
The Problem of Dying Batteries
Well companies like Tesla run into to problems due to lack of technology. Electric cars have batteries almost the length of the vehicle because we can't figure out how to get more storage out of a smaller battery so they went with bigger batteries, you can only go so big. We've hit the limit on battery room, this is why electric cars are not distance efficient. They can only go a small amount of miles (150-250).
12 Volt batteries are pretty close to being perfected. The main problem is dying batteries. Overtime they will just give out. The plates will sulfate until they can no longer hold voltage. Batteries sulfating is a pretty big problem because they are extremely explosive. When a battery dies you have to charge it up. When you do put it on a charger the plates inside the battery heat up and begin to give off a gas(sulfation) the gas when mixed with o2 makes hydrogen which is very flammable. Many people have been hurt from exploding batteries. I don't think there are any batteries that do not have the risks associated with dying batteries (flammable). Even a solar power has to be able to store voltage with plates.
How To Safely Charge a Dying Car Battery
If you have to charge a battery there are two settings high charge and low (you can get a charger from Walmart or an auto store). The high charge(1 hour) heats the plates up very quickly so it gases much more. A slow charge (10hours) will not gas near as much. You can smell the gas. It smells like rotten eggs and its strong. If you smell the gas do not disconnect the charger only turn it off then disconnect. You do not want an accidental spark. It gases when the battery dies, but its a very low amount.
Is there a way to differentiate a good car battery from a bad one?
It really depends on a car because manufacturers call for different batteries (See a list of 2017 car battery reviews from EquipmentArea). You can't just pick out a battery it needs to be the one your car calls for. AGM batteries are very popular because instead of flat square plates there is a spiral so there's more surface area so more storage(they last longer). They can cost anywhere from $100-400 but everyday vehicles just need a lower end AGM for around $100. Yes they have different ratting like CCAs.
CCAs are important not many people know what they are just that their car calls for a certain amount. CCA is cold cranking amps. Its how much amps is drawn from your battery when started. If you have lets say a car that calls for 600 Cca and you put a battery with 400 Cca it can take your battery below its specs. It will either not start correctly or will kill your battery life over time