When charging a maintenance-free (lead-calcium) battery, which of the following statements is true?

When charging a maintenance-free (lead-calcium) battery, the statement that the battery may not accept a charge for several hours, yet may still be a good battery, accurately reflects the peculiar characteristics of these types of batteries. Lead-calcium batteries are known for having a relatively long recovery time due to their chemistry and internal structure. In certain situations, if the battery has been deeply discharged, it may take some time before it begins to accept charge effectively, but this does not necessarily indicate that the battery is defective or no longer functional.

Rather, this time delay can be attributed to various phenomena such as internal resistance and the formation of sulfation at the plates, which can create a temporary condition where the battery appears non-responsive to charging methods. Understanding this characteristic is crucial for technicians to avoid prematurely concluding that a battery is bad simply because it does not accept charge immediately.

The other statements are not universally valid. For instance, while a charging rate of 25 amperes may be appropriate for certain circumstances depending on battery size, it is not a definitive rule applicable to all lead-calcium batteries. Additionally, while battery temperature is an important factor to monitor during charging, it is essential to refer to manufacturer specifications since the safe operating temperature may vary notably with