MPPT solar charger manual

The DC loads in the system can be connected to the load output terminals. The solar charger controls the load output and disconnects the loads if the battery voltage drops too low, safeguarding the battery against too-deep discharges.

The disconnect voltage of the load output and the battery management algorithm can be configured via a jumper in the VE.Direct port or via the VictronConnect app. For more information refer to the Load output settings chapter.

The current rating of the load output is 15A or 20A (depending on the MPPT model) and is short-circuit proof.

Solar charger system with DC loads connected to the load output

Some loads, particularly inverters, have a higher current rating or high start-up current rating, exceeding the load output's capacity. These loads should be connected directly to the battery. The solar charger can still control these loads to prevent deep battery discharges by linking the load's remote on/off terminal to the solar charger load output. Depending on the load's on/off terminal type, a specific interface cable, such as an Inverting remote on/off cable , might be necessary.

Solar charger system with inverter connected directly to the battery and controlled by the load output

Alternatively, a BatteryProtect can be used to control the load.

Solar charger system with DC loads connected directly to the battery via a BatteryProtect controlled by the load output

A virtual load output can be established to control loads with current ratings greater than the solar charger's load output.

The virtual load output can be set up within the VictronConnect app and controlled using battery voltages or the BatteryLife algorithm. For details on the configuration process, please consult the Load output settings chapter.

When the solar charger 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 BatteryLife 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 onward, the load disconnect level will be modulated so that a nearly 100% recharge is achieved about once every week.

The solar charger is a 3-stage charger. The charge stages are: Bulk – Absorption – Float.

Bulk

During the bulk stage, the solar charger delivers the maximum charge current, to rapidly charge the batteries. During this stage, the battery voltage will slowly increase. Once the battery voltage has reached the set absorption voltage, the bulk stage stops and the absorption stage commences.

Absorption

During the absorption stage, the solar charger has switched to constant voltage mode. The current flowing to the battery will gradually decrease. Once the current has dropped below 1A (tail current), the absorption stage stops and the float stage will commence.

When only shallow discharges occur the absorption time is kept short. This is to prevent overcharging of the battery. But if the battery was deeply discharged, the absorption time is automatically increased, to make sure that the battery is fully recharged.

Float

During the float stage, the voltage is reduced, and the battery's fully charged state is maintained.

The VictronConnect app allows selection of 8 pre-set charge algorithms, or alternatively the charge algorithm is fully programmable. The charge voltages, stage duration and the charge current can be customized.

Some lead-acid battery types need a periodic equalization charge. During equalization the charge voltage will be increased above the regular charge voltages to achieve cell balancing.

If an equalization charge is required it can be enabled using the VictronConnect app.

The solar charger has a built-in internal temperature sensor.

The internal temperature is used to set the temperature compensated charge voltages. For this, the internal temperature when the solar charger is "cold" is used. The solar charger is "cold" when there is only little current flowing into the battery. Be aware that this is only an estimation of the ambient and the battery temperature. Should a more accurate battery temperate be needed, consider using an external battery temperature sensor, see chapter External temperature and voltage sensor.

The temperature compensation range is 6°C to 40°C (39°F to 104°F).

The internal temperature sensor is also used to determine if the solar charger is overheated.

The (optional) Smart Battery Sense is a wireless battery voltage and temperature sensor and can be used with the solar charger. It measures the battery temperature and the battery voltage and sends this via Bluetooth to the solar charger.

The solar charger uses the Smart Battery Sense measurements for:

The solar charger communicates with the Smart Battery Sense via Bluetooth using a VE.Smart Network. For more detail on the VE.Smart network see the VE.Smart Networking manual.

Alternatively, a VE.Smart Network that measures battery temperature and battery voltage, can also be set up between a solar charger and a BMV-712 Smart or SmartShunt battery monitor that has been equipped with a Temperature sensor for BMV, without the need for a Smart Battery Sense.

Example of a VE.Smart Network of a Smart Battery Sense and a solar charger.