The second stage in a modern
3-step+ charging process.
Batteries are charged from around 80 %
up to 100 % during this stage. Voltage is
somewhat lower than the gas voltage of
the battery, which is 2.4 volt per cell at
20 °C (or 14.4 volt for a 12-volt and 28.8
volt for a 24-volt battery). The absorption
phase follows the bulk phase and is, in
turn, followed by the float phase.
The American Boat & Yacht Council is a
non-profit organisation that represents
American builders. It sets standards
and gives recommendations for
nautical equipment (including electrical
equipment) on pleasure vessels with the
goal of enhancing
safety. The ABYC
Battery in which the electrolyte (a mix
of water and sulphuric acid) is largely
absorbed in glass fibre matting. As these
batteries are entirely maintenance-free
and do not normally produce gas, they
can be fitted anywhere and ventilation
is usually unnecessary. Thanks to their
construction, AGM batteries can be
swiftly discharged while providing a very
powerful current. This makes them highly
suitable for systems that require high
levels of current, such as bowthrusters,
winches and engine starting.
A contact in a battery charger or inverter
that is activated when an external or
internal malfunction occurs.
Alternating current (AC)
AC is the electricity that for example
comes out a socket in your home.
Other terms used for AC include shore
power, generator power or inverter
An electrolyte that consists of water
and sulphuric acid. The specific gravity
of battery acid in a charged battery
varies between 1.28 and 1.30.
Used to charge batteries. Its capacity
should be at least 15 to 25 % of the
battery capacity with a flooded battery
and max. 30 % with an AGM battery, up
to 50 % with a Gel battery and up to
100 % with a Lithium Ion battery.
Battery Management System
A natural phenomenon of Li-ion
batteries is the natural imbalance
between stronger and weaker cells.
In the charging process, one or more
cells will reach their maximum charge
level faster due to this imbalance,
while others do not get fully charged.
The lower cells will be discharged
faster, causing the battery to be
empty sooner due to under-voltage
and so reducing the lifespan of the
battery. To prevent this, Mastervolt
Lithium Ion batteries are equipped
with a Battery Management System
that automatically compensates for
the imbalance between the cells and
increases the lifespan and the total
capacity of the battery.
Indicates the battery status. Mastervolt
offers a selection of 4 models. Firstly,
the BattMan with spray-proof display
and energy meter, which is available
in two models. Next is the Masterlink
BTM-III with detailed battery infor-
mation via the LCD display and LED
bar. The modern MasterShunt com-
bined with the EasyView 5 provides
detailed information on voltage, cur-
rent, and historical and user data. It is
easily installed within the MasterBus
network, with touchscreen controls for
all functions. See pages 114-115 in this
Powerbook for more information on
the battery monitors.
AC voltage changes polarity with a given
frequency: In Europe, for instance,
the polarity of the electrical voltage
is reversed 50 times per second. The
supply therefore has a frequency of 50
Amperian is a powerful digital assistant
that monitors your Mastervolt system
anywhere in the world. Amperian allows
you or your system provider to remotely
operate and monitor your power system.
all system data
The unit that measures the current
following through a circuit. The current
can be calculated by dividing the voltage
by the resistance of the consumer.
A resistance of 6 ohm and voltage of
12 volt gives a current of 2 amps.
The unit that denotes the capacity of a
battery, calculated by multiplying current
in amps by the duration of the discharge
in hours. For example: If a battery
delivers a current of 5 amps in 20 hours
with the voltage constantly above 10.5
volt, this amounts to 20 x 5 =100 Ah.
The capacity of a battery usually
depends on the amount of lead and
battery acid it contains.
Converts chemical energy
into electrical power and vice
versa. The nominal voltage of a battery is
2 volt, and higher voltages are achieved
by connecting several batteries in series.
For instance, six 2-volt batteries can be
combined to provide a nominal voltage
of 12 volt.
Technical terms - glossary