Alkaline batteries are reccomended for smoke alarms for the following reasons.
A zinc carbon battery will work fine, but has a shorter life, increasing the risk of a dead battery when called upon. Greatly increases labour costs if someone is paid to replace batteries.
The cheaper rechargeable batteries (6 cell, 7.2 volt) will give frequent low battery alarms. The better type of rechargeable batteries (7 cell, 8.4 volt) work better. The average tenant is unable to master rechargeables. Also the voltage drops relatively quickly at end of life and wont give the low battery alarm for long.
Disposable lithium 9 volt batteries (3 lithium manganese dioxide cells, true 9 volts) work fine but are too expensive for general use, and also suffer from sudden death.
Lithium batteries have the merit of extreme shelf life and freedom from leakage, useful for test instruments etc. Little advantage for a smoke alarm.
Alkaline batteries are reccomended for smoke alarms for the following reasons.
A zinc carbon battery will work fine, but has a shorter life, increasing the risk of a dead battery when called upon. Greatly increases labour costs if someone is paid to replace batteries.
The cheaper rechargeable batteries (6 cell, 7.2 volt) will give frequent low battery alarms. The better type of rechargeable batteries (7 cell, 8.4 volt) work better. The average tenant is unable to master rechargeables. Also the voltage drops relatively quickly at end of life and wont give the low battery alarm for long.
Disposable lithium 9 volt batteries (3 lithium manganese dioxide cells, true 9 volts) work fine but are too expensive for general use, and also suffer from sudden death.
Lithium batteries have the merit of extreme shelf life and freedom from leakage, useful for test instruments etc. Little advantage for a smoke alarm.
