Mastervolt AGM batteries combine both "starter" and "service" functions into a single 12V semi-deep cycle AGM battery. They are ideal general purpose batteries.
As a starter battery they deliver short bursts of high current to power engine starting, side thrusters, winches, etc.
As a service battery they are designed to easily withstand cyclical use for onboard lighting, instrumentation, entertainment, etc.

Of course, these batteries include all the advantages of Absorbed Glass Mat battery technology: maintenance-free, no fumes, can't spill or leak, very low self-discharge rate, not affected by freezing, etc.

Note that this particular battery does not conveniently fall into a battery "group". As with any other battery, select it because it fits your dimension and specification requirements.

Both "starter" and "service" functions
Extremely long life span
Entirely maintenance-free and safe
Can be installed in any position
First-rate condition even after winter storage
Suitable for 3-step Plus charging method
Voltage is 12V DC
Overall dimension (including terminals): 16.1"L x 7.0"W x 8.9"H
Weight is 83 lb
Two-year warranty


Heavy on the technical side...

AGM Batteries
In AGM batteries, the electrolyte (mixture of water and sulphuric acid) is largely absorbed in layers of fiberglass.
This type of battery is entirely maintenance-free and there is no gas formation with normal use.
Not requiring any ventilation, these batteries can be installed anywhere.
Their construction gives a very fast discharge at very high currents so AGM batteries are ideal for systems that require high currents (for instance when starting an engine).
The battery poles can be unscrewed and this type of battery can be combined with every standard battery terminal.

AGM batteries make ideal universal batteries.
They have excellent starter function, and are a perfect upgrade for older wet lead acid batteries. During starting, a 90 amp hour AGM battery provides the same initial power surge as a 180 amp hour wet lead-acid battery.
Glass-fiber technology ensures low internal resistance.
Use of thicker plates allows deep discharging without damaging the battery during cyclical use.