Victron energy BlueSolar MPPT 75/10 Anleitung Seite 9

Battery voltage Vb (@start-up)
Vb < 11,9V
11,9V < Vb < 12,2V
12,2V < Vb < 12,6V
Vb > 12,6V
(12V values, adjust for 24V))
Default absorption voltage: 14,4V
Default float voltage: 13,8V
The absorption time counter starts once switched from bulk to absorption.
The MPPT Solar Chargers will also end absorption and switch to float when the battery
current drops below a low current threshold limit, the 'tail current'.
The default tail current value is 1A.
For models with a load output the current on the battery terminals is used; and for the
larger models; the current on the output terminals is used.
The default settings (voltages, absorption time multiplier and tail current) can be modified
with the Victronconnect app via Bluetooth (VE.Direct Bluetooth Smart dongle needed) or
via VE.Direct.
There are two exceptions to normal operation:
1. When used in an ESS system; the solar charger algorithm is disabled; and instead it
follows the curve as mandated by the inverter/charger.
2. For CAN-bus Lithium batteries, like BYD, the battery tells the system, including the
solar charger, what charge voltage to use. This Charge Voltage Limit (CVL) is for some
batteries even dynamic; changes over time; based on for example maximum cell
voltage in the pack and other parameters.
Variations to expected behaviour
1. Pausing of the absorption time counter
The absorption time counter starts when the configured absorption voltage is reached
and pauses when the output voltage is below the configured absorption voltage.
An example of when this voltage drop could occur is when PV power (due to clouds,
trees, bridges) is insufficient to charge the battery and to power the loads.
When the absorption timer is paused, the absorption LED will flash very slowly.
2. Restarting the charge process
The charging algorithm will reset if charging has stopped for an hour. This may occur
when the PV voltage drops below the battery voltage due to bad weather, shade or
similar.
3. Battery being charged or discharged before solar charging begins
The automatic absorption time is based on the start-up battery voltage (see table). This
absorption time estimation can be incorrect if there is an additional charge source (eg
alternator) or load on the batteries.
This is an inherent issue in the default algorithm. However, in most cases it is still better
than a fixed absorption time regardless of other charge sources or battery state.
It is possible to override the default absorption time algorithm by setting a fixed
Multiplier Maximum absorption time
x 1
x 2/3
x 1/3
x 1/6
6h
4h
2h
1h