Final answer:
The charge status of a no-maintenance battery is typically determined using a battery tester, which assesses the terminal voltage under a load condition. These battery testers can range from large devices for substantial batteries to small testers with digital displays for smaller batteries. Additionally, a hydrometer can be used for lead-acid batteries to check their state of charge.
Step-by-step explanation:
The status of the charge of a no-maintenance battery can be determined using a battery tester. These devices measure the battery's terminal voltage under a load to evaluate its condition. Large battery testers, like those used on the USS Nimitz, have a small resistance that can dissipate large amounts of power, indicating they are built to handle substantial batteries.
Small battery testers typically feature a digital display to show the acceptability of terminal voltage for smaller batteries. While it's challenging to measure a battery's internal resistance directly, a battery tester can provide this measurement. If the internal resistance is high, it suggests that the battery is weak, as reflected in a lowered terminal voltage.
In addition, for lead-acid batteries, a hydrometer can be used to test the specific gravity of each cell, which is a measure of its state of charge. Overcharging a battery can lead to electrolysis of water, especially if the voltage per cell exceeds 2.04 V.
With NiMH batteries, commonly used in hybrid automobiles, they have better capacity but a greater self-discharge rate and a more limited service life when compared to NiCad batteries. Understanding batteries also involves knowing that they are rated by voltage and charge capacity, with charge capacity typically measured in Amp-hours (Ah) or milli-amp-hours (mAh).