So I need to know how do I figure out total power needed and if my idea is enough....sorry as im having trouble putting thoughts into words at the moment lol
Basically i am building a self sufficient weather station that will be web accessible by using gsm/gprs shield.
I plan to use solar panels to charge the batteries i have
I have 2 of those grey, sealed rechargeable valve regulated batteries (yuasa NP7-12) 12V 7.0 Ah
I dont know if one would be good or need 2?
Do i just add the arduino and shields power consumption together?
man im frustrated....my apologies if not enough info
Start with actual total current drawn if possible, the shield data will be for full load which you may not reach.
Then look at the datasheets for your choice of battery, these will tell you what maximum discharge current is for a range of options down to a predetermined level (Volts Per Cell, multiply by 6 to get end voltage for a 12 volt battery system).
You need to consider minimum sun hours and an allowance for wet days etc when designing your P.V. and Battery systems.
You will also want to look for the most efficient voltage conversion from the nominal 12VDC to 5VDC to run the Arduino etc.
To protect the batteries build a LVD (Low Voltage Disconnect) circuit into your Code.
@shaneidleman, that 12v lead-acid battery would be fine if your solar panels can keep it charged. You need to figure out, on the one hand, how much energy your Arduino will consume and on the other hand, what is the least amount of solar energy you can harvest over (say) 7 days. For long life lead-acid batteries should receive a full charge about once per week. There is a lot of info about batteries at the Battery Universty web site.
You should assume that the actual capacity of a battery is no more than 50% of the sticker value.