General Description - Victron energy BlueSolar MPPT 75/15 Manual

1 General Description

1.1 Ultra fast MPPT tracking
Especially in case of a clouded sky, when light intensity is changing continuously, a fast
MPPT algorithm will improve energy harvest by up to 30% compared to PWM charge
controllers and by up to 10% compared to slower MPPT controllers.
1.2 VE.Direct
For a wired data connection to a Color Control panel, PC or other devices
1.3 Load output
Deep discharge of the battery can be prevented by connecting all loads to the load
output. The load output will disconnect the load when the battery has been discharged to
a pre-set voltage.
Alternatively, an intelligent battery management algorithm can be chosen: see Battery
Life.
The load output is short circuit proof.
Some loads (especially inverters) can best be connected directly to the battery, and the
inverter remote control connected to the load output. A special interface cable may be
needed, please see section 3.6.
1.4 Battery Life: intelligent battery management
When a solar charge controller is not able to recharge the battery to its full capacity within
one day, the result is often that the battery will continually be cycled between a 'partially
charged' state and the 'end of discharge' state. This mode of operation (no regular full
recharge) will destroy a lead-acid battery within weeks or months.
The Battery Life algorithm will monitor the state of charge of the battery and, if needed,
day by day slightly increase the load disconnect level (i.e. disconnect the load earlier)
until the harvested solar energy is sufficient to recharge the battery to nearly the full
100%. From that point onwards the load disconnect level will be modulated so that a
nearly 100% recharge is achieved about once every week.
1.5 Three step charging
The controller is configured for a three step charging process: Bulk – Absorption - Float.
See section 3.8 and section 5 for default settings.
See section 1.8 for user defined settings
1.5.1. Bulk
During this stage the controller delivers as much charge current as possible to rapidly
recharge the batteries.
1.5.2. Absorption
When the battery voltage reaches the absorption voltage setting, the controller switches to
constant voltage mode.
When only shallow discharges occur the absorption time is kept short in order to prevent
overcharging of the battery. After a deep discharge the absorption time is automatically
increased to make sure that the battery is completely recharged.
Additionally, the absorption period is also ended when the charge current decreases to less
than 1A.
1.5.3. Float
During this stage, float voltage is applied to the battery to maintain a fully charged state.
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