The lifespan of a battery will vary considerably with how it is used, how it is maintained and charged, the temperature and other factors. Also the type of battery will determine its lifespan.
If kept in a charged state when unused, the common lifespan of a 12-volt Gel or AGM battery is up to six years. After five or six years of float voltage at an average ambient temperature of 25 ºC, the battery still retains 80 % of its original capacity. Higher average temperatures will shorten the lifespan of the battery. The number of charge and discharge cycles of a 12-volt battery is strongly correlated to its structure and quality. Mastervolt’s 12-volt Gel batteries can take around 500 full cycles of being discharged down to 20 % and charged back to full capacity.
Most manufacturers consider batteries to be spent at a remaining capacity of 80 %. This does not, however, mean that the battery has to be replaced immediately. For example, the battery can still be used if only 50 % of the battery capacity is actually required. It is therefore not necessary to replace the battery after six years or 500 full cycles. An average use of seven years is perfectly normal for 12-volt Gel or AGM batteries.
The lifespan for 2-volt traction Gel cells is at least 15 years and the maximum number of full cycles is 1000-1500 when discharging to 20 % of capacity. These batteries are therefore highly suitable for larger systems that require intensive use and a very long lifespan.
Mastervolt Lithium Ion batteries have a lifespan of more than 2000 cycles, which is three times longer than most standard lead-acid batteries. They have an extremely long lifespan due to aspects such as the battery management, very low self-discharge, the lack of memory effect and a discharge of up 20 %.