Victron Cyrix Battery Combiners

Victron Cyrix Battery Combiners Description

The Cyrix Battery Combiner is a microprocessor controlled heavy duty relay that automatically connects batteries in parallel when one of them has reached a pre-set voltage (indicating that the battery is being charged), and disconnects when the voltage decreases below float level (indicating that one or more batteries are being discharged). Cyrix Battery Combiners are an excellent replacement for diode isolators. The main feature is that there is virtually no voltage loss so that the output voltage of alternators or battery chargers does not need to be increased.

Cyrix-Li-load

The Cyrix-Li-load will disengage when its control input becomes free floating. If the battery voltage recovers after disconnecting (which will happen when no other loads are connected to the battery), the output of the BMS will become high and the Cyrix will reengage after 30 seconds. After 3 attempts to reengage, the Cyrix will remain disengaged until battery voltage has increased to more than 13V (resp. 26V or 52V) during at least 30 seconds (which is a sign that the battery is being recharged).

Cyrix-Li-Charge

The Cyrix-Li-Charge will connect a battery charger with 3 seconds delay:

• if the charge disconnect output of the VE.Bus BMS is high, and
• if it senses 13,0 V (resp. 26,0 V or 52,0 V) or more on its battery charger connection terminal
• if it senses 2 V or more on its battery terminal (the Cyrix will remain open if not connect to the battery).

The Cyrix-Li-Charge will disengage immediately whenever its control input becomes free floating, signalling cell over voltage or cell over temperature.
In general, a cell over voltage alarm will reset shortly after charging has been stopped. The Cyrix will then reconnect the charger after a delay 3 seconds. When the Cyrix-Li-Charge is engaged (charger connected to battery) it will disengage after 1 hour to check if the charger is still enabled.. If, after the Cyrix has disengaged, the output of the battery charger immediately increases to 13,0 V or more, the Cyrix will reengage, with a 3 seconds delay.

Note: In case of zero discharge current, or a small discharge current, the Cyrix will not disengage shortly after the charger has
been switched off and/or disconnected, because battery voltage will remain higher than 13,5 V.

Cyrix-ct 

Intelligent battery monitoring to prevent unwanted switching

Some battery combiners (also called voltage controlled relay, or split charge relay) will disconnect a battery in case of a short but high amperage load. A battery combiner also may fail to connect a large but discharged battery bank because the DC voltage immediately drops below the disengage value once the batteries are connected. The software of the Cyrix-ct 12/24 does more than simply connect and disconnect based on battery voltage and with a fixed time delay. The Cyrix-ct 12/24 looks at the general trend (voltage increasing or decreasing) and reverses a previous action only if the trend has reversed during a certain period of time. The time delay depends on the voltage deviation from the trend.

Cyrix-Li-ct

The functionality of the Cyrix-Li-ct is analogous to the Cyrix-ct.
The Cyrix-Li-ct will parallel connect a lead acid starter battery and a LiFePO4 battery:

• if the Charge Disconnect output of the VE.Bus BMS is high, and
• if it senses 13,4V (resp. 26,8V) or more on one of its power terminals.

The Cyrix will disengage immediately:

• when its control output becomes free floating, signalling cell over voltage or cell over temperature
• when battery voltage drops below 13,2V.

Start assist function: a short negative pulse will close the relay during 30 seconds.

A built-in transient voltage suppressor will limit the voltage spike that may occur when the Cyrix suddenly disengages due tocell overvoltage or over temperature.

Cyrix-i

New: intelligent battery monitoring to prevent unwanted switching
Some battery combiners will disconnect a battery in case of a short but high amperage load. A battery combiner also may fail to connect a large but discharged battery bank because the DC voltage immediately drops below the disengage value once the batteries are connected. The software of the Cyrix-i does more than simply connect and disconnect based on battery voltage and with a fixed time delay. The Cyrix-i looks at the general trend (voltage increasing or decreasing) and reverses a previous action only if the trend has reversed during a certain period of time. The time delay depends on the voltage deviation from the trend. In addition, four switch timing profiles can be chosen.