Panasonic BP-5917C40 Technical Handbook page 42

SOLAR CELL DESIGN - CONTINUED
2. Selection of Solar cell and Battery
2. Selection of Solar Cell and Battery
Equipment operating voltage
Equipment current consumption
Equipment operating time
2) Calculation of operating current required from
solar cell
3.34
I =
P
0.85 x 0.95 x 3.21
3) Calculation of storage battery capacity
C=
4) Calculation of solar cell operating voltage
On the basis of the above, the most appropriate solar cell model is:
the solar module BP-HK36K (Vp=16.7V, Ip=1.44A)
the most appropriate storage battery is: the sealed lead-acid battery LS-90-6E(12V, 90Ah)
Panasonic
V =12V
L
I =20W/12V=1.67A
L
T=2h/day
= 1.29(A)
3.34 x 20
= 83.5(Ah)
0.8
Solar Cells Handbook, Page 41
1) Calculation of average current consumption
per day
1
* Solar cell average rated output generation time
per day: 3.21 hours
* Number of non-illumination backup days: 20
(Set at 7-30 days, taking into account equipment
performance)
VP = 14.5 + 0.4 + 0.5 + 1.3 = 16.7V
Storage battery charging voltage
=1.67 x 2
R
= 3.34 (Ah/day)
August 1998