wattstunde Nova Series, Manual

Page: 31 / 42

WATTSTUNDE GmbH
Bessemerstraße 3
21339 Lüneburg
info@wattstunde.de
10
Lithium-iron-phosphate battery
Nova-Series
Charge and discharge
The individual cell voltages within the battery may differ due to high discharge currents and
short charge retention voltage periods.
In this case, fully charge the battery and leave it connected to the charger for several hours.
The integrated BMS will then compensate for the voltage difference.
The cycle capacity may deviate from the nominal capacity due to the change in working
temperature and the charging and discharging rate.
The battery can be fast charged. This greatly reduces the time spent connected to the mains.
Long waiting times are eliminated. Due to the non existent memory effect in the battery, it
does not always have to be fully charged. The service life is even incr eased if the battery is
not always charged to a charge level of 100 %. Adjustments to previously used devices such
as a solar charge controller or similar are not absolutely necessary to charge the battery.
We generally recommend using suitable 3 stage CCCV chargers with a lithium charging
characteristic and a suitable cut off voltage (see data sheet) for the longest service life.
The battery should be used regularly to maintain the capacity of the battery and to calibrate
the charge status. Sometimes there is a SoC error due to missing calibration charges.
We recommend repeating the calibration several times.
First discharge the battery to approx. 10 % (SoC) and then fully charge it to 100 % (SoC).
Do not exceed the maximum permissible charging voltage.
Only charge / discharge the battery within the specified temperature range.
Only switch on the charger after connecting it to the battery. After charging, first switch off
the charger and then disconnect the battery from the charger.
The battery management system (BMS) automatically balances the cells if necessary.
Please be sure to adhere to the maximum charging/discharging currents specified in the
data sheet!
4