The Lithium Ion battery
Mastervolt’s Lithium Ion batteries are
based on Lithium Ion iron phosphate,
which has an energy density three times
higher than that of lead-acid batteries.
Although there are materials with an
even higher energy density, these are
generally considered less safe. The
Mastervolt Lithium Ion batteries are
therefore considered one of the safest
batteries of their type.
A unique feature is their built-in Battery
Management System (BMS). The system
monitors the cells and guarantees
optimal safety. Mastervolt Lithium Ion
batteries are MasterBus compatible, and
up to 15 % more efficient compared to
other Li-ion batteries available.
This gives you:
Shorter charging times.
Less generator time required
More power than from a
traditional battery of the same
A normal open lead-acid battery,
for example, has a DOD (depth of
discharge) of 50 %. This means
that you can only use up to 200 Ah
from a 400 Ah battery. A Mastervolt
Lithium Ion has a DOD of 80 %,
almost 60 % more usable battery
capacity. With this percentage, a
battery of 400 Ah supplies 320 Ah,
or 120 Ah more.
2 V Gel battery
The second design is a 2-volt traction
battery, available in capacities up to
2700 Ah and highly suitable for systems
with frequent and significant discharging
where a long lifespan is needed. For a
battery of 12 or 24 volt, six or twelve Gel
batteries need to be connected in series
to provide the required voltage.
Major benefits of Gel batteries include
very limited self-discharging, the
possibility of a short charging time, and
the lack of gas production under normal
circumstances. All of this makes Gel
batteries very suitable for heavy cyclical
The AGM battery
A different type of lead-acid battery is
the AGM (Absorbed Glass Mat) battery.
In this model, the electrolyte (water
and sulphuric acid) is absorbed into an
extremely delicate glass fibre mat. Just
like with any other battery, charging
generates hydrogen gas and oxygen,
which are transported through the
capillary tubes of the glass fibre mat.
Once the two gases are recombined,
water is once again obtained and
subsequently reabsorbed into the glass
fibre mat. The recombination process is
The glass fibre mat also serves as
insulation between the plates, allowing
the plates to be close together and
leading to very low internal resistance.
This means that a high discharge current
is no problem. The charge current could
be a little lower than with Gel batteries
(approx. 30 %) because the glass fibre
mat is also an efficient heat insulator,
and heat generated by charging is
gradually conducted to the outside
of the case. This requires the charge
current to be somewhat restricted and
results in a slightly longer charging time.
AGM batteries are highly suitable for
applications requiring a high discharge
current, such as a bowthruster or
winches and for medium cycle use.
The AGM battery is entirely closed and
therefore maintenance-free. If the AGM
battery is overcharged, for instance
due to the use of a (cheap) unregulated
battery charger, a small amount of
hydrogen gas is formed. This gas escapes
through a special vent in the battery
casing that is designed to prevent oxygen
from entering the battery. Incorrect
charging will reduce the battery’s
MLI batteries are ideally suited for electric
and hybrid propulsion, and can be
connected unlimited in parallel or up to
ten units in series (series connection is not
possible for the MLI-E model).
MLS batteries are not suitable for series
connection, but can be configured
unlimited in parallel (see manual for more
Another benefit is that Lithium Ion
batteries weigh less and require less space.