Battery Charging Facts

There are three types of lead-acid battery that are commonly used in motorhomes, caravans, boats and other vehicles for the purpose of providing 12V power in the living area. They are wet lead-acid, AGM and gel. Each type of battery has advantages and disadvantages and each requires different charging regimes. An "intelligent" battery charger such as those from CTEK, Sterling and NDS will adjust itself as required or, in some cases, can be set at a certain voltage. The optimum voltage depends on the temperature of the battery but, as a general rule in the U.K., these are the suggested charging voltages for lead-acid batteries.

 

Standard wet lead-acid batteries

Bulk stage:

14.4V

Absorption stage:

14.4V

Float stage:

13.6V

Reconditioning stage:

 

AGM batteries

15.8V

 

Bulk stage:

14.7V

Absorption stage:

14.7V

Float stage:

13.6V

Reconditioning stage:

 

GEL batteries

N/A

Bulk stage:

14.4V

Absorption stage:

14.4V

Float stage:

Reconditioning stage:

13.6V

 N/A

 

Lithium batteries

Lithium batteries are starting to become accepted as having unbeatable performance when used as leisure batteries.

Bulk voltage 14.2V - 14.8V

Absorption Voltage 14.2V - 14.8V

Float voltage 13.6V - 13.8V