Modern lithium ion batteries are comparatively safe, and Empowering E-Bike battery packs are built using the safer 'family' of lithium ion cells (mixed Mn / Ni / Co chemistries rather than the more volatile Co chemistries used in mobile phones and laptops). However, any lithium battery represents a potential risk of sudden electrical discharge and heat generation due to the high density of stored energy (and relatively large size in the case of electric bike batteries). Furthermore, in addition to safety, battery lifetime and performance are optimised by understanding how to treat lithium batteries.
Best practice for use, storage and charging of lithium batteries are given below accordingly. While many of the points apply to all lithium batteries, the information presented is specifically orientated to standard Empowering E-Bike battery packs.
Any concerns over a battery provided, please contact Empowering E-Bikes for advice / support.
- It is recommended
to treat any battery as a potential source of fire due to its high stored
energy content and potential for high rate of discharge of this energy in the
event of internal or external short circuiting. This is analogous to a can of
petrol; it is not hazardous of itself, but should be stored and used in an
appropriate manner to minimise risk. In particular, charging (which is
effectively adding energy to the battery and hence the most likely cause of
failure) should be conducted in a safe and non-flammable location where the
impact of any sudden extreme heat generation would be mitigated i.e. in a
location away from people and any immediately combustible environments. Storage
should likewise be somewhere where failure would minimise risk.
- Batteries should never be charged above
42V (fully charged state) or discharged below ~25-30V (fully discharged state).
Battery voltages beyond either of these states can damage the cells which will
then give a significant risk of failure during subsequent charging. The charger
circuitry (charging), battery management system (charging and discharging) and bike
motor controller (discharging) do not allow these conditions to occur and
therefore these conditions would require multiple failures to take place and
would be very unlikely in the event of proper use. However, if a battery is
known to be in one of these states then please contact Empowering E-Bikes.
- Do not charge using a different
charger to that supplied by Empowering
E-Bikes, particularly those with a
charge current of greater than 5 Amps (faster charging equals greater heat
generation and shorted battery lifetime).
- Charging should never be conducted
when the battery is at a temperature lower than 0°C. The battery will appear to
charge normally, however the process may, over time, lead to the formation of internal lithium
metal deposits that can short circuit and / or permanently damage the battery.
- Although the charger will cut out
automatically when charging is complete, it is best not to leave the charger
switched on for extended periods after charging.
- Do not attempt to charge a battery
while simultaneously discharging it.
- Do not use the battery for an application
other than that intended
- Never externally short circuit a
- Minimise exposure to vibration.
- Avoid impact: avoid placing the
battery in locations where it could fall, and place it carefully onto hard
- Never use a battery if it has any
evidence of damage due to impact or other causes.. If in any doubt please
contact Empowering E-Bikes for advice.
- Avoid exposure to water and / or
prolonged moist environments. While the battery (and other system components
except where highlighted) are comparatively water resistant they should not be
considered to be water proof. Always allow to dry as soon as possible after use
in the rain (corrosion of connectors can lead to loss of performance).
- Never expose a battery to sources of
heat, or store at temperatures above 30°C on a prolonged basis.
- Never open the battery pack
- Do not leave the battery where
children or animals can access them, or allow a child to handle or use it.
- All Empowering E-Bike
batteries and systems are set up with female terminals on the battery side of
any connection to minimise the possibility of accidental contact with positive
and negative terminals simultaneously (i.e. short circuit / electric shock). Take
care to avoid contact with the battery terminals; the voltages involved should
not be sufficient to pass through dry skin, even in the event of contact with
both terminals. However, they could give a serious electrical shock in the
event of contact with moist skin, or for example via contact with a metal item
that causes a short circuit (e.g. jewelry).
- Do not store loose metal items in the
vicinity of the battery
- Do not dispose of the battery except
via an appropriate route. If preferred, Empowering
E-Bikes will dispose of batteries if
Do NOT attempt to use the battery if:
is charged above 42 Volts or discharged below 25 Volts
battery fails to charge or discharge, or does not show a voltage
charger repeatedly cuts out and starts up at the end of the charge cycle
sudden reduction in effective battery capacity is observed
is any known impact or obvious physical damage to the battery, or fluid coming
from the battery
sparking or heat damage to the battery, or the battery becomes excessively hot
to the touch during charging or operation
other concerns over battery integrity
Even though modern lithium batteries are comparatively long lived, all batteries will deteriorate over time and with a large number of charge cycles. For optimum lifetime, especially if the battery is not used regularly
that the battery is discharged / charged at least once every 1-3 months
in a cool location (<25°C)
- Store in a state of mostly, but not completely charged, for example 80% of capacity or 40.5V. The exact level is not critical; the key point is to avoid full charge or discharge for extended periods
Note that Li batteries have no 'memory effect' and do not have to be fully discharged before recharging. In fact, it is better for the battery to avoid full discharge, and recharge whenever possible, even if only partially discharged. It is also better for bike performance to keep a good level of charge. Firstly, motor speed is proportional to voltage and will reduce as the battery discharges (and drops from 42V to 30V). Secondly, a deeply discharged battery is less able to support high current and so may cut out temporarily when working hard, even if not fully discharged.
Although it is most important to avoid over heating the battery, battery performance is optimum at around 20°C and reduces significantly by 0°C. Therefore when using the battery is winter ensure that the battery is stored indoors prior to use wherever possible.
Please ask for advice if in any doubt regarding any aspect of
battery safety or use.