You can not. Looks like you have the two and eight backwards in the question as you can reconfigure eight 2 volt batteries to produce 12 volts.
Think out of the box. Parallel two sets of two batteries in series for a total of four volts. Then add four batteries in series for an additional eight volts. You now have a total of twelve volts.
No.
By connecting two 6 volt auto batteries in series. Or by connecting eight 1.5 volt batteries in series.
Yes, if the two 6 volt batteries were connected together in series.
lithium-ion battery
Two 6 volt batteries in series, yes. In parallel, no.
Yes. Used in golf carts and other small vehicles. Google "8 volt batteries" and take your pick.
The charger needs to be set to charge for the voltage that the battery is designed to produce. Most car batteries are 12 volt batteries.
use two 12 volt batteries in series.
They make a 7.5 volt battery when put together
A 3 volt battery is a battery that produces 3 volts. Many watch batteries produce 3 volts.
If you have two 6 volt batteries you can take a jumper wire and connect the negative post on one battery to the positive post on the other battery then connect the remaining pos and neg posts to the 12 volt battery charger.
To get 24 volts from two 12 volt batteries, hook the positive post from one battery to the negative post of the other.