User manual
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You can perform this experiment with different light sources, e.g. with sunlight,
a halogen lamp, a light bulb, a ashlight, an energy savings lamp, a uorescent
lamp, etc. You can tell by the brightness at which the LED is lit whether they are
suitable or less suitable light sources. This experiment is important to teach you
about suitable lighting for the subsequent experiments.
14.1 Charging Rechargeable Batteries with Solar Energy
Test setup: Solar modules, plug board, LED red, battery holder, rechargeable
battery
If there is sufcient sunlight available, it is a lot of fun to use this energy to charge
rechargeable batteries. The power is free of charge and you are independent of a
socket.
The solar module of the learning package can be used to charge any previously
described rechargeable battery types, such as NiMh, NiCd, NiZn, Li-Ion and LiPo.
The solar module has a great technical benet. Both for power limiting and for the
maximum charge voltage, you usually do not need any further components if the
solar module has been adjusted to the power conditions of the rechargeable bat-
tery. Thus, the solar module from the learning package – which supplies approx.
35 mA current and a maximum voltage of 4.5 V at full sunlight, can safely load
the listed rechargeable battery types and also ensure that any self-retention will
automatically be balanced out (charge retention).
The proportionality of solar module and rechargeable battery changes in
„larger“ (higher-performing) solar modules that can supply more current and
higher voltages. A charging current limitation and/or charging electronics are
urgently required then. Else, the rechargeable battery will be damaged or
destroyed.