Frequently Asked Questions (FAQ’s)

How do you charge the batteries correctly?
The standard charging profile is a 2 stage regime i.e. constant current followed by constant voltage. Note that lead acid chargers may not be used with LiFeBATT modules. Please contact your LiFeBATT agent/reseller for more information.

What type of charger should I buy?
LiFeBATT recommends and supplies programmable single and three phase high frequency chargers. Please contact your LiFeBATT agent/reseller for more information.

Balancing during charge - Why is it important?
Due to the way the modules/batteries are constructed, from many internal cells, it is very important that during charging these cell are allowed to balance (i.e. reach the same charge level), otherwise the total battery capacity may be slightly degraded. This balancing is performed by a LiFeBATT proprietary Voltage Management System (VMS) which continuously monitors the cell voltages and ensures that the complete module is balanced.

When and how often is balancing needed?
Balancing is performed by the VMS internally to the battery and is performed on a continuous basis, during charge and discharge, to ensure that the cells are balanced and therefore the maximum capacity is achieved.

What’s the correct orientation when batteries are fitted?
LiFeBATT XPS Modules can be positioned in any orientation, it is recommended that when considering the layout of the complete assembly that care should be taken to ensure connecting cables are of similar lengths.

What’s a Battery Protection Module, BPM? Is it necessary?
The LiFeBATT battery System is complete with cell balancing and monitoring through the Voltage Management System (VMS). It does not turn off the load or charger, this function is performed by the Battery Protection Module (BPM). The BPM has been designed to integrate with the applications control system and charger to provide a complete battery management system. It effectively stops your battery system from being damaged providing protection and control on charge and regen circuits and on traction/discharge circuits. Further protection is also provided if the module is subjected to excessive temperatures. For further details please Click here to download the Quick Start Guide.

Do I need to cover the battery to protect against moisture ingress?
We recommend that the batteries are installed in a location where direct application of water is avoided and certainly there should be no pooling of water on any surface of the battery. It is recommended that the batteries as with other electronic components contained in the appliance are contained in a suitable enclosure rated for the environment it will be operating under.

Why are the battery modules the shape they are?

LiFeBATT provide 3 cells with form factors of 38123 and 40166, these sizes dictate the overall dimenssions and size of the module. The XPS Modules have been developed to match existing automotive industry BCI form factors and capacities, as well as being scalable to allow larger packs to be built up into complex physical dimensions.

Can I have other shapes of battery module?
We are able to assemble completely bespoke systems to match your strored energy, space and weight specification. Please contact your LiFeBATT agent/reseller such that your requirements can be discussed in more detail.

Are the batteries OK for automotive use in terms of vibration and shock resistance?
Yes our batteries are already providing motive power in hybrid and electric vehicles and are approved to standards IEC61960, DIN VG96 924.

What’s the best securing method when mounting the batteries?
They should be restrained from movement in all 3 axes without excessive single point pressure on the reinforced plastic case.

Is cooling required on battery packs?
This really depends on the environment and the typical energy usage profile. A small capacity pack which is being “worked hard” will generate more heat than larger capacity pack. In charge the batteries should be operated between 0 & +45 degrees Celsius and in discharge the batteries should be operated between -20 & +60 degrees Celsius. Please contact your LiFeBATT agent/reseller for more information.

Can the batteries be deep discharged? How can they be recovered if this happens?
The Lithium Iron Phosphate (LiFePO4) chemistry does not exhibit any ‘memory’ effect in the way other types of batteries do, so remain usable across 100% of capacity. However the batteries must remain above minimum voltage (>2.0V per cell block) to protect the cells from possible reverse currents, once the battery reaches this minimum level it should not be left at this level and must be recovered up to its normal operational voltage as soon as possible. It is recommended that the module/battery is cycled if stored for longer than 4 months even if it is fully charged at the beginning of the storage or non operational period.

How do I replace a module in an in-service battery pack?
The fundamental safety rule is that batteries at different states of charge should not be connected together. Electrical isolation of batteries at different states of charge must be maintained until all modules in the pack (including the new replacement) are fully charged. For help to achieve this it is strongly advisable to contact your LiFeBATT agent/reseller for more information.

How does the VMS know which module is which?
Each module is programmed with individual ID number e.g. 001 and the VMS can address directly with each module on a shared RS232 communication channel.

How many LiFeBATT modules can be hooked to a single BPM?
256 is the present limit due to the addressing limitation on the shared RS232 communication link. Please contact your LiFeBATT agent/reseller for more information.

What CAN BUS protocols do you support?
The normal CAN interface is SAE J1939 CAN 2.0B standard 11bit message addressing with rate options for 125/250/ 500Kbits. Also extra interface hardware can extend the message addressing to 29bit to accommodate the host controller in certain applications. (Check wording!!!!). Please contact your LiFeBATT agent/reseller for more information.

What flexibility do you have when integrating the batteries into a system?
The modular sizing and programmable options on the BPM/CAN allows for faster integration than many competitors.
In order to give you a more comprehensive answer it will be necessary to better understand your system needs. Please contact your LiFeBATT agent/reseller for more information and support.

How do I select the right battery for my application?
The important factors are to match;

• The battery pack voltage and system minimum and maximum voltages.
• The battery capacity in Amp hours needs to be matched with nominal current consumption and run-time.
• The system peak discharge current must be carefully matched to battery specification and if necessary a larger capacity pack chosen to prevent overheating.
• The total weight and dimensions also need to balance with these overall factors.

Do batteries self-discharge when not in use?
Yes there is a small self discharge with all battery chemistries, however LiFeBATT LiFePO4 modules can be stored for up to 1 year without needing to be re-charged, however to ensure maximum performance it is recommended that the module is recharged after 4 months of storage. Caution: the self discharge is accelerated with higher storage temperature (>45degrees C).
Note: In all situations it is advisable to check the condition and state of charge every month to ensure that batteries are not over discharged. Please contact your LiFeBATT agent/reseller for more information.

How does temperature affect the performance of my batteries?
At higher temperature the capacity will be reduced and constant exposure will cause increasing capacity fade. At lower temperature the impedance will be higher reducing efficiency of charging and discharging.
The VMS/BPM will protect the system from short term over temperature operations but the installation must keep the batteries within the recommended temperature for operation -20 to +60 degrees C at all times. Room temperature is the optimum for both long life and performance. Please contact your LiFeBATT agent/reseller for more information.

If your application is designed to work in extreme conditions please contact one of our application engineering team or your LiFeBATT agent/reseller for more information.