What is the likely result of service and charging nickel-cadmium and lead acid batteries together in the same service area?

• A. Reduced charging efficiency
• B. No interaction
• C. Increased life expectancy
• D. Contamination of both batteries

Answer: (D)

The scenario tests how different battery chemistries interact when placed in the same service area. Nickel-cadmium and lead-acid batteries use different electrolytes and have different venting and charging characteristics. If they are serviced or charged near each other, leakage, splashes, or vented gases from one can contaminate the other. Lead-acid batteries contain sulfuric acid, while nickel-cadmium batteries use alkaline potassium hydroxide; contact between their electrolytes or exposure to each other’s fumes can corrode terminals, foul or mix electrolytes, and damage separators, degrading performance in both batteries. That cross-contamination is the most likely result, making both batteries vulnerable to failure.

Other options don’t fit as well: simply reduced charging efficiency isn’t the primary outcome described by proximity and mixing of chemistries; no interaction ignores the clear incompatibilities; increased life expectancy is unrealistic given the likelihood of contamination and damage.