The voltage across each component in a parallel circuit is the same. Similarly, total current is the sum of currents flowing through each component. Parallel wiring of a golf cart battery bank is unusual. The terminals are linked in order for golf cart battery bank wiring in a series circuit. This is shown in the diagram below.
When you connect two or more batteries in series, the negative ends of all the batteries must be connected together and only then can they be connected to the power source. For example, if you were to connect three 1.5 V AA batteries in series, the resulting voltage would be 3 x 1.5 = 4.5 V, enough to damage most electronics unless they are designed to handle this level of voltage.
In the case of the golf cart battery bank, all of the batteries are connected in series. This means that whatever charge is present on any one cell will be shared by all other cells in the group. In addition, because all the cells are connected in series, any one cell can only supply as much current as another cell allows. For example, if one of the cells in the group has no reserve capacity left while others still have plenty of life left in them, then it will be the only cell that can't deliver its full potential output. This could lead to some components being used more heavily than others, which could cause premature wear-and-tear and reduce the golf cart's overall performance.
Because the same electrons must flow at the same rate across all of the batteries, the current in each battery and circuit must be the same. When batteries are linked in parallel, the current flowing through the circuit grows in direct proportion to the number of batteries in the circuit. In this case, it's best if the batteries are equal in capacity so that they will drain evenly.
For example, if you have four 1.5 V AA batteries, the total voltage is 3 volts, and the total current is 1.5 amps. If you link three of these batteries in parallel, the resulting voltage is 4.5 volts and the resulting current is 3 amps. Now, if one of the batteries was replaced with a new one, then the other two would still have enough power to run everything plugged into them. However, if four 5 V AAA batteries were used in place of the 1.5 V batteries, then only one-fourth as much current would flow, or 0.5 amp instead of 1.5 amps.
This is why battery connections should be equal partners; if one battery dies, it won't cause problems for the others.
Also, there should be no current flowing through any single battery when it is not being charged or discharged. Otherwise, that battery will fail prematurely due to overcharging or undercharging.
By lowering total resistance, connecting batteries in parallel enhances total current capacity and overall amp-hour capacity. A parallel bank's batteries must all have the same voltage rating. They can be any size or type of battery you want as long as they are from the same manufacturer and have the same charge level. The number of connections between batteries will determine how many amps of current they can supply combined.
For example, if you connect two AA batteries in parallel, they will both supply 1.5 volts when powered individually and together they will provide 3 volts. This means that each battery will be able to deliver 1.5 amps of current independently and together they can deliver 3 amps. As you can see, the more batteries you connect in parallel, the higher the current capacity.
Batteries cannot supply different amounts of current. If you connect two identical batteries in parallel and try to use one them to supply more current than the other, they will soon be damaged. To avoid this problem, make sure that all batteries you connect in parallel are equal in size and voltage rating. Then connect as many of them together as possible without exceeding your equipment's power requirements.
When looking at how many amps of current a system requires, remember to consider both peak current levels and average current levels.