Lynx Shunt VE.Can (M8)

This parameter is used to tell the battery monitor how big the battery is. This setting should already have been done during the initial installation.

The setting is the battery capacity in Amp-hours (Ah).

For more information on the battery capacity and the related Peukert exponent see the Battery capacity and Peukert exponent chapter.

The battery voltage must be above this voltage level to consider the battery as fully charged. As soon as the battery monitor detects that the voltage of the battery has reached this “charged voltage” parameter and the current has dropped below the “tail current” parameter for a certain amount of time, the battery monitor will set the state of charge to 100%.

The “charged voltage” parameter should be set to 0.2V or 0.3V below the float voltage of the charger.

The table below indicates the recommended settings for lead acid batteries.

The battery is considered as fully charged once the charge current has dropped to less than this “Tail current” parameter. The “Tail current” parameter is expressed as a percentage of the battery capacity.

Note that some battery chargers stop charging when the current drops below a set threshold. In these cases, the tail current must be set higher than this threshold.

As soon as the battery monitor detects that the voltage of the battery has reached the set “Charged voltage” parameter and the current has dropped below this “Tail current” parameter for a certain amount of time, the battery monitor will set the state of charge to 100%.

This is the time the “Charged voltage” parameter and the “Tail current” parameter must be met in order to consider the battery fully charged.

Set the Peukert exponent parameter according to the battery specification sheet. If the Peukert exponent is unknown, set it at 1.25 for lead-acid batteries and set it at 1.05 for lithium batteries. A value of 1.00 disables the Peukert compensation. The Peukert value for lead-acid batteries can be calculated. For more information on the Peukert calculation, the Peukert exponent and how this relates to the battery capacity, see the Battery capacity and Peukert exponent chapter.

The “Charge Efficiency Factor” compensates for the capacity (Ah) losses during charging. A setting of 100% means that there are no losses.

A charge efficiency of 95% means that 10Ah must be transferred to the battery to get 9.5Ah actually stored in the battery. The charge efficiency of a battery depends on battery type, age and usage. The battery monitor takes this phenomenon into account with the charge efficiency factor.

The charge efficiency of a lead acid battery is almost 100% as long as no gas generation takes place. Gassing means that part of the charge current is not transformed into chemical energy, which is stored in the plates of the battery, but is used to decompose water into oxygen and hydrogen gas (highly explosive!). The energy stored in the plates can be retrieved during the next discharge, whereas the energy used to decompose water is lost. Gassing can easily be observed in flooded batteries. Please note that the ‘oxygen only’ end of the charge phase of sealed (VRLA) gel and AGM batteries also results in a reduced charge efficiency.

When the current measured falls below the “Current threshold” parameter it will be considered zero. The “Current threshold” is used to cancel out very small currents that can negatively affect the long-term state of charge readout in noisy environments. For example, if the actual long-term current is 0.0A and, due to injected noise or small offsets, the battery monitor measures ­0.05A the battery monitor might, in the long term, incorrectly indicate that the battery is empty or will need to be recharged. When the current threshold in this example is set to 0.1A, the battery monitor calculates with 0.0A so that errors are eliminated.

A value of 0.0A disables this function.

The time-to-go averaging period specifies the time window (in minutes) that the moving averaging filter works. A value of 0 (zero) disables the filter and gives an instantaneous (real-time) readout. However, the displayed “Time remaining” value may fluctuate heavily. Selecting the longest time, 12 minutes, will ensure that only long-term load fluctuations are included in the “Time remaining” calculations.

This option can be used to manually synchronise the battery monitor.

In the VictronConnect app press the ”Synchronise” button to synchronise the battery monitor to 100%.

This option can be used to calibrate the zero reading if the battery monitor reads a non-zero current even when there is no load and the battery is not being charged.

A zero current calibration is (almost) never needed. Only perform this procedure in case the battery monitor shows a current while you are absolutely sure that there is no actual current flowing. The only way to be sure is to physically disconnect all wires and cables connected to the side of the shunt. Do this by unscrewing the shunt bolt and removing all cables and wires from that side of the shunt. The alternative, switching loads or chargers off, is NOT accurate enough as this does not eliminate small standby currents.