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Old 09-07-11, 01:18 AM   #11
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Adding a wind power generator will be great. You may try this.

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Old 09-07-11, 11:24 AM   #12
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just to throw my shoe into the ring ...

103 @ 25% max. discharge /1.9 ah = more like 12 hours of continuous power. do you really need to run the pump 24/7? As many have pointed out (okay so I'm a lurker) the actual draw may be less than the rating indicates.

Also, when the sun shines not only will your batteries be charging but the draw will be covered by the panels. How much PV are putting into them?

@indyplumber/guercio: the windmaps for Ontario indicate a "poor" for windpower. Unless he's on a great lake or some'at.

not being an engineer means I'm big on "try it and see if it works..." so good luck! this summer I went from small 12 volt "trailer" deep cycle, to two 235 amp/hr 6 volts in series--1 250 watt panel in; to two 395 amp/hr 6 volts in series--2 250 watt panels in; to aha, this works!
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Old 09-25-12, 02:14 PM   #13
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How long will a 12v battery last with a .0228kW drain on it?
If I have say a 800cranking amp deep cycle battery?

12v Load = 1.9A
12v x 1.9A = 22.8W = P


1.Add up the hours that each Load will be on for to get the Total of Energy Consumed.
2.From that you can Calculate everything you need IE: Solar Panel / Battery / Regulator

My Calculations

1 X 12V Pump @ 22.8W
on for (SEE CHART) hours per night

-Watt/Hour Chart-
1 hour = 22.8Wh
2 hour = 45.6Wh
4 hour = 91.2Wh
8 hour = 182.4Wh

Total usage per night in Winter = 182.4Wh/d

-Load and Battery -

Consumption = 182.4Wh over 8 hours
182.4 watt-hours divided by 12 volts = 15.2 amp hours taken from system in 1 night

Because we can only use half the energy in a lead acid battery without harming the battery,
the minimum battery size is 15.2 amps / .5 = 30.4Ah.

30% Discharge rule - the minimum battery size is 15.2 amps / .3 = 50.67Ah.
20% Discharge rule - the minimum battery size is 15.2 amps / .2 = 76Ah.

choose what calculation will be best for your battery !!
10% discharge is a non no.

I want my system to be reliable if we have four consecutive days of cloudy weather,
(using the 30% Discharge rule) 4 days of autonomy x 50.67Ah = 202.68Ah for the battery. = 210Ah + battery
(Required Battery Bank = 1 x 200 or 220 Ah True Deep Cycle


-Charging Battery from Panel-
This installation is in a location that gets 4 hours of full sun per day.
Check the charts for this depending on the month in the Season.
To recharge the battery for one day of use we need 50.67 amps in 4 hours = 50.67 / 4 = 12.7amps from a 12 volt solar panel array.

-Solar Panel -
Most load calculations include a discount factor for the inefficiency of recharging the battery.
20% is typical. 12.7 / 0.8 = 15.83A

A 2 x 140W solar array that has an Impp (amps maximum power point) of 7.7A = 15.4A would be suitable


-Charge Controller Rating in AMPS-
The 2 x 140W solar array has a short circuit amp rating (Isc) of 2 x 8.2A = 16.4A
16.4A x 1.25 = 20.5A
use a 20.5A or larger charge controller with this array to charge the battery.

Cheap example - 30A Unit
For best efficiency to charge use an MPPT Type.

- estimated Cost of mentioned Materials -

Have seen 2 x 140w poly panel on Net for $340 inc delivery
Have seen 220Ah Varta Leisure Battery 12V 220Ah for around $300 inc delivery
20A Charge controller $80 - mppt prefered of course
Mounting Bracket for Panel = $20

Estimated Total = $640ish

Also required - Fuse box / switches / bits .. !!

Question ...If above calculations are based on a maximum of 8 hours use = 640
so 4 hours would mean 320 and 2 hours would = $160 for a 45.6W/h Load would all this calculate back nicely ?

-Solar Panel specification-
STK-140P6-A ...... manufactured by 3E
Related power
Open circuit voltage Voc(V)
Short-circuit current Isc(A)
Optimum operation voltage Vmp(V)
Optimum operation current Imp(A)

The above methods of calculation have all been taken from the Net over time !!
They seem to work, but if you think they are wrong then let me know.

Remember 12V Batteries should be fused and Stored in a safe manner
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Old 11-29-12, 10:26 AM   #14
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