The N in the battery group size indicates a reserve capacity of 95 amps at 90 minutes discharge. The group number 75 defines the physical size of the battery. So, the battery with the letter N has a higher reserve power compared to the C battery installed in the car.
AAA batteries are a thinner and shorter version of AA. C batteries and D batteries get progressively larger. All these batteries are usually 1.5V, the larger battery size offering a longer lifetime. If more than 1.5V is required, then multiple batteries are used together. 9V batteries are cuboid-shaped with both terminals on the top of the battery.
Different manufacturers use different letters, such as N, C, or T (T for Home Depot), to denote their battery groups. The difference between N and T batteries lies in their design. Some battery groups, like 24 and 27, have an R or L to indicate the position of the positive terminal.
The N or C on a battery is a performance parameter. In your case, the N means a reserve capacity of 95 amps at 90 minutes discharge. The C battery you have installed is rated at 25 amps at 90 minutes reserve. The group number, which is 75 in this case, defines the physical size of the battery.
Some batteries are known as dual-purpose batteries and are designed to be both starting batteries and deep-cycle batteries. The main difference between these two types of batteries is their cold-cranking amps (CCA) rating. A starting or dual-purpose battery will have a higher CCA than a deep-cycle battery. How Do You Recharge a Car Battery?
9V batteries are cuboid-shaped with both terminals on the top of the battery. Button-shaped batteries are used in small devices that don’t require a high power output, such as watches or kitchen scales. Other devices may have batteries shaped specifically for them by the manufacturer.