This common 12 volt battery is designed about half way between a deep cycle and a shallow cycle, and has medium length of life. Sealed batteries can be excellent deep cycle alternative energy batteries, cleaner and safer, but only if charging is precisely controlled. Since water cannot be replaced and hydrometer testing is not possible, they are not usually recommended for use. Unlike lead, deep discharge and failure to recharge do not shorten battery life. However, surplus batteries are often overpriced and defective.
Cost is much higher than lead acid.
Voltage swings higher when charging and lower when using. Disposal and recycling can be difficult and costly. Be cautious of buying used alkaline batteries. Usually no shipping charges or tax. Call for arrangements.