The LiFePO4 battery: preventing cell under voltage, over voltage and over temperature
The first line of protection is cell balancing. All Victron LiFePO4 batteries have integrated cell balancing. The second line of protection consists of:
- shut down of the load in case of imminent cell under voltage, and
- shut down or reduction of the charging current in case of imminent cell over voltage, high temperature (>50°C) or low temperature (<0°C). The VE.Bus BMS is the core of the second protection line. However, not all loads or chargers can be controlled directly by the VE.Bus BMS. In order to shut down such loads or chargers several VE.Bus BMS controllable Cyrix switches are available.><0°C)
The VE.Bus BMS is the core of the second protection line. However, not all loads or chargers can be controlled directly by the VE.Bus BMS. In order to shut down such loads or chargers several VE.Bus BMS controllable Cyrix switches are available.
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). Alternatively, a BatteryProtect can be used (advantage: very low power consumption).
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 13,7V (resp. 27,4V or 54,8V) or more on its battery charger connection terminal, and
- if it senses 2V 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 of 3 seconds. After two attempts to reengage with 3 seconds delay, the delay increases to 10 minutes. Whenever battery voltage is less than 13,5V (resp. 27V or 54V), the Cyrix will disengage with a delay of 1 hour.
Note 1: 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 13,5V.
Note 2: If, after the Cyrix has disengaged, the output of the battery charger immediately increases to 13,7V or more, the Cyrix will re-engage, with 3 seconds delay.
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, and/or
- when battery voltage drops below 13,2V. Start assist function: a short positive pulse will close the relay during 30 seconds (see figure on page 2).
A built-in transient voltage suppressor will limit the voltage spike that may occur when the Cyrix suddenly disengages due to cell overvoltage or over temperature.
Victron Energy Limited Warranty Policy
Victron Energy warrants its products to be free from defects in workmanship and materials for a period of 5 years from the date of purchase by the end user, with a maximum of 66 months from the Victron Energy invoice date. Exceptions on this are: lead acid batteries; 2 years from date of purchase by the end user, with a maximum of 30 months from the Victron Energy invoice date, Lithium-ion batteries; 3 years from date of purchase by the end user. In addition to this proof of correct battery usage is required when making a battery warranty claim.
During this period, Victron Energy will, at its option, repair or replace the defective product free of charge. The warranty does not include performing or reimbursing de‐installation, transportation and re‐installation. This warranty will be considered void if the unit has suffered any physical damage or alteration, either internally or externally, and does not cover damages arising from improper use like:
• Reverse of battery polarity.
• Inadequate connection.
• Mechanical shock or deformation.
• Contact with liquid or oxidation by condensation.
• Use in inappropriate environment (dust, corrosive vapor, humidity, high temperature, biological infestation...).
• Breakage or damage due to lightning.
• Connection terminals and screws destroyed or other damages, like overheat, due to insufficient tightening.
• For any electronical breakage except due to lightning (reverse polarity, over‐voltage due to external cause), the state ofthe internal control diode and of the inputs/output X and Y capacitors determine the warranty.
This warranty will not apply where the product has been misused, neglected, improperly installed, or repaired by anyone else than Victron Energy or one of its authorized Qualified Service Partners. In order to qualify for the warranty, the product must not be disassembled or modified.
Repair or replacement are our sole remedies and Victron Energy shall not be liable for damages, whether direct, incidental,special, or consequential, even caused by negligence or fault.
Victron Energy owns all parts removed from repaired products. Victron Energy uses new or reconditioned parts made by various manufacturers in performing warranty repairs and building replacement products. If Victron Energy repairs or replaces a part of a product, its warranty term is not extended. In case of replacement the new component has a warranty of 6 months, without effect on the initial warranty period. All remedies and the measure for damages are limited to the above. Victron Energy shall in no event be liable for consequential, incidental, contingent orspecial damages, even if having been advised of the probability of such damages. Any and all other warranties expressed or implied arising by law, course of dealing, course of performance, usage of trade or otherwise, including but not limited to implied warranties of merchantability and fitness for a particular purpose, are limited in duration to a period of two (2) years from the date of purchase.
Life Support Policy
As a general policy, Victron Energy, does not recommend the use of any of its products in life support applications where failure or malfunction of the Victron Energy's product can be reasonably expected to cause failure of the life support device or to significantly affect its safety or effectiveness. Victron Energy does not recommend the use of any of its products in direct patient care. Victron Energy will not knowingly sell its products for use in such applications unless it receives in writing assurances satisfactory to Victron Energy that the risks of injury or damage have been minimized, the customer assumes all such risks, and the Liability of Victron Energy is adequately protected under the circumstances.
As a product requires service, it must be brought back to the place of purchase. In case no contact can be taken with the merchant, or if he is either unable or not allowed to provide service, direct contact should be taken with Victron Energy.
Warranty on Repairs
The warranty period on products or on printed circuits boards repaired by Victron Energy as well as on printed circuit boards for replacement is 6 months from delivery by Victron Energy.
It is the responsibility of the sender to sufficiently package these products. The transport must be organized in a way to avoid any damage, especially when a single unit or heavy unit is sent.
If a part of the terms and conditions set out above is held invalid, void or unenforceable due to any particular national or international legislation, it shall not affect other parts of the terms and conditions remaining.
For Australia only
Our goods come with guarantees that cannot be excluded under the Australian Consumer Law. You are entitled to a replacement or refund for a major failure and compensation for any other reasonably foreseeable loss or damage. You are also entitled to have the goods repaired or replaced if the goods fail to be of acceptable quality and the failure does not amount to a major failure.