FAQ

General

Are the lithium batteries OK for automotive use in terms of vibration and shock resistance?

Super B lithium batteries don’t have specific automotive certifications, they do however comply with UN38.3 which is related to shock and vibration during transportation.

Can different battery types be put in one system?

No, please refrain in just using one battery type per system.

Can I have redundancy in the battery pack in the event of failure?

This is an extra option already installed and operational on some large electric vehicle systems with parallel battery systems. It gives the reassurance that in the event of a single point fault the remaining portion of the battery pack will continue to provide energy. It is enabled through extra control and switching wiring and also involves an additional level of management control supervision which Super-B have developed and can support.

Can lithium batteries be replace lead-acid batteries without modification to the system?

No, chargers need to be suitable for lithium. Higher capacity batteries can also create higher currents, which emphasize the need of thicker cables.

Do we need to install a covered battery tray as your product is IP 56 – 50 & 51 rated?

Ingress Protection (IP) Ratings.

We recommend that the lithium 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. A covered tray is ideal but it does not need to be environmentally sealed. Tray designs should incorporate measures to prevent direct exposure to large volumes of water and also incorporate drainage if the worst should happen.

As with all batteries with exposed terminals it is strongly advisable where salt spray is a possibility that it should not be able build up around electrical connections.

In all situations a periodic visual inspection is recommended to check the integrity of the tray.

Note that the Nomia lithium batteries are IP50 rated.
Epsilon is rated IP51.

How do I replace a module in an in-service battery pack?

The fundamental safety rule is that lithium 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 the Applications Engineering team for support. Only certified technicians are allowed to modify power cabling and installations.

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.

 

How does temperature affect the performance of my lithium 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 BMS will protect the system from short term over temperature and low temperature operations but the installation must keep the batteries within the recommended temperature.

How many battery modules can be managed by a single BCI/BIB?

For the Nomia series it is possible to have up to 99 batteries. With Epsilon we have tested up to 8 in parallel and no option to stack them in series.

Is a booster needed in combination with a traction battery, and a EURO 6 engine?

Yes it is needed with EURO 6 engines, to stabilize the voltage and current.

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. (Ask Super B for advice!)

What is the correct orientation when lithium batteries are fitted?

Any orientation is possible as there is no free electrolyte inside, however we recommend the terminals are upright, particularly when sideways mounted. (no upside down orientation with terminals on the bottom).

What’s the best securing method when mounting the lithium batteries?

They should be restrained from movement in all 3 axes without excessive single point pressure on the re-enforced plastic case.

This can be accomplished by fitting them in a tray base with high density foam and insulated securing bar across the top to stop any vertical movement. It is advisable to keep terminals and communication terminals accessible for periodic inspection and in some applications allow space for cooling airflow.

Why are the battery modules the shape they are?

The present generation has 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

Charging & Discharging

Balancing during charge. Why is it important?

Due to the way the lithium batteries are constructed from many internal cell blocks it is very important that during charging these cell blocks are allowed to balance (i.e. reach the same charge level), otherwise the total battery output performance would be limited by the cell block which is lowest charge state.

This balancing should be performed as often as possible to keep the overall capacity optimum and ensure that all lithium batteries within a pack are contributing equally to the total output.

Calibrating State of charge (SOC), what way does it work? How often do I need to fully charge and discharge to reset SOC?

The complex SOC algorithm has been developed by Super-B to give a prediction of the remaining capacity based on many real time measurements inside each of the modules. The accuracy of the SOC is very good but its linearity benefits from regular full charge (100% SOC) & cell balancing, and also from periodic discharge below approx. 20% where a re-calibration is performed on each module.

Generally in vehicle applications we advise the period of this re-calibration can be determined during initial trials so that it can be incorporated within a timeframe alongside other service intervals.

At low consumption it is important to note that the SOC of the battery can drift – a regular full charge of the batteries does help limit the drift.

Can the charger be connected to lithium batteries permanently?

Only the chargers that have a float phase can be connected permanently to lithium iron phosphate batteries (LiFePO4).

When batteries are fully charged the charger will remain in floating mode.

Can the lithium batteries be deep discharged? How can they be recovered if this happens?

The Lithium phosphate chemistry (LiFePO4) 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 (>2.3V 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.

For the Epsilon the minimum voltage per cell is defined at 2.25V. For the Nomia lithium batteries it is 2.05V per cell block.

In case of deep discharge we can sometimes recover the lihtium battery with a very low current. It is not recommended unless it is performed within our laboratory or in specific situations at the customer with Super B expert/engineering assistance.

Do lithium batteries self-discharge when not in use?

Yes there is a small self-discharge with traction batteries but they can be stored, when full, for up to 6 months without needing to be re-charged. Caution: the self-discharge is accelerated with higher storage temperature (>45 degrees C).

The traction batteries have internal protection electronics which consume current and if stored need to be put into ‘shelf mode’ for reduced current drain.

In all situations it is advisable to check the condition and state of charge periodically to ensure that batteries are not over discharged.

How do you charge the lithium batteries correctly?

Ideally lithium batteries should be charged in 3 stages:

  1. Super B suggests C/3 for a better lifespan of the batteries & 1C as maximum charging current.
  2. Allowed to equalize & balance cells at this level until fully charged
  3. Return to float charge at 13.8V.

This is similar to many intelligent lead acid chargers which commonly have 14.4V as an acceptable steady voltage in equalization phase.

Apart from the charge current limits which are higher for Super B. For the rest the same applies for Super B lithium batteries.

Communication, BMS, BCI and BIB

What CAN BUS protocols do you support?

Super B uses only CANopen protocol. We can support customers in interfacing & adapting to different protocols they are using.

What is a BMS? Is it necessary?

A Battery Management System is necessary for control and protection during discharge and charging. The BMS provides CAN bus communication of battery status ‘state of charge’ and alarms etc. It may also be used without CAN bus interface with just basic analog inputs and outputs for simpler systems.

How many battery modules can be managed by a single BCI/BIB?

For the Nomia series it is possible to have up to 99 batteries. With Epsilon we have tested up to 8 in parallel and no option to stack them in series.

How does the BMS know which module is which?

Each module is programmed with individual ID number e.g. 001 and the BMS can address directly with each module on a shared communication channel.

Troubleshooting

Epsilon

I experience bluetooth connections problems with the Epsilon. How can I solve this?

The loss of connection to Bluetooth is a known problem that we have fixed via various updates of the battery software. Have you made these updates?

  • First, check that your Be in Charge Android phone app is up to date. (V3.0.6).
  • In a second step there is a manual procedure to reset the Bluetooth battery. To perform this procedure, you must electrically disconnect your battery from the system. I recommend the mass (-) be careful not to touch the positive (+) with.
  • Then you can press the red S1 button and your battery will turn back on.
  • You should be able to connect to the battery
  • Once connected, check that your battery is up to date (presence of a white arrow in an orange circle at the top if it is not up to date). If so, please update by clicking on the button just before.
  • During the update if possible deactivate the standby mode of your phone and make sure to have an internet connection available.
  • If your battery has not been updated for more than a year, your indicated charge percentage may change to 1%. To recalibrate it to the real level, you have to recharge your battery until it reaches a voltage of 14.4V. The time depends on the state of charge of your battery before updating.