Flexible Charge Algorithm; Equalization Charging; Temperature Sensing; Internal Temperature Sensor - Victron energy MPPT 150/70 Manual

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 2A (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.
A storage stage is not needed for solar chargers, unlike for AC chargers, since at night there is no solar
power, so battery charging will stop.

3.10.2. Flexible charge algorithm

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.
In addition to this, 8 pre-programmed algorithms can be set with a rotary switch.

3.10.3. Equalization charging

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.

3.11. Temperature sensing

Temperature sensing allows for temperature compensated charging. The absorption and float charge voltages are adjusted based
on either the battery temperature (accessory needed) or otherwise on the solar charger internal temperature.
Temperature compensated battery charging is needed when charging lead-acid batteries in hot or cold environments.
The temperature compensation can be enabled or disabled in the solar charger settings and the amount of compensation, the
compensation coefficient (mV/°C), is adjustable.

3.11.1. Internal temperature sensor

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
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.

3.11.2. External temperature and voltage sensor

The (optional) Smart Battery Sense
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:
• Temperature compensated charging using the actual battery temperature, rather than the solar charger's internal temperature.
An accurate battery temperature measurement will improve charging efficiency and prolong the life of lead-acid batteries.
• Voltage compensation. The charge voltage is increased to compensate in case there is a voltage drop over the battery cables
during high current charging.
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
Page 8
MPPT solar charger manual
External temperature and voltage sensor
is a wireless battery voltage and temperature sensor and can be used with the solar charger.
manual.
[8].
Features