Battery Calculate time to recharge saxo battery with solar panel

stefano · Nov 7, 2016

Good evening, i would like to know if someone knows how to calculate the time that would take to a solar panel of this kind Rotola in su pannelli solari produttore-Celle solari, pannello solare-Id prodotto:60489237141-italian.alibaba.com - https://italian.alibaba.com/product-detail/roll-up-solar-panels-manufacturer-60489237141.html of 1,5 sm (square meters) of area to recharge a battery of a citroen saxo completely descharged with these specifications (in "standard" conditions):

Car Battery 60Ah 540A BOSCH CITROËN SAXO (S0, S1) 1.5 D KW 40 CV 54
Batteria auto 60Ah 540A BOSCH CITROËN SAXO (S0, S1) 1.5 D KW 40 CV 54 | eBay - http://www.ebay.it/itm/Batteria-auto-60Ah-540A-BOSCH-CITROEN-SAXO-S0-S1-1-5-D-KW-40-CV-54/162269913779?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D39923%26meid%3D1105f76f2e6e438d94ed37908c766fef%26pid%3D100005%26rk%3D2%26rkt%3D6%26sd%3D231233489407

Could you provide also the formulas so that i can do other calculations by myself? Thanks a lot fot the help you will provide!

sparksburnout · Nov 7, 2016

No Sunshine.

Silly Sausage · Nov 7, 2016

Mi dispiace, non posso aiutarti. Non parlo italiano.

westward10 · Nov 8, 2016

dmxtothemax · Nov 8, 2016

it will take about 100hrs at full output.
considering you only get about 6hrs a day of full output
about 15 days

Lucien Nunes · Nov 8, 2016

Panel rated 100W output will be at around 16-17V for a standard 36-cell panel. Its maximum current will be around 100/16= 6.25A in direct sunlight. A typical recommended bulk charge rate for lead acid batteries is C/5, in your case 60/5=12A, up to about 85% state of charge, after which a reduction to around C/20 is needed to prevent battery damage, 60/20=3A.

In direct sunlight, with a suitable charge controller, therefore:
0.85*60=51Ah at C/5
51/6.25=8h bulk charge (limited by panel)
0.15*60=9Ah at C/20
9/3=3h completion (limited by battery)

Therefore the absolute minimum, under ideal conditions, would be around 8+3=11 hours. If direct sunlight is not available then the bulk charge time will increase significantly, maybe doubled. An appropriate controller will be required as the battery would soon be damaged by continuous charging at 6A once fully charged.