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TECHNICAL BACKGROUND

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:

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Shorter charging times.

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Less generator time required

for charging.

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More power than from a

traditional battery of the same

dimensions.

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

applications.

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

then complete.

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

lifespan.

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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).

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MLS batteries are not suitable for series

connection, but can be configured

unlimited in parallel (see manual for more

information).

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Another benefit is that Lithium Ion

batteries weigh less and require less space.

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