Solar Panel To Battery Help - Page 3

Worth1 · March 12, 2016

Quote:

Originally Posted by PureHarvest

What's it cost?
What do you do when the wind stops?

Prices vary from 400 to over 700 bucks and then when the wind stops you are juiced and have to convert back to solar.

But in a weeks time you would hope it would put out enough power to recharge the battery.
The minimum for a 400 watt generator is a 100 amp hour 12 volt battery.

zeuspaul · March 12, 2016

I do the math a little differently. I prefer watts because a 104 watt pump is 104 watts no matter the source voltage. For example your 104 watt pump draws .9 amps from 120 volts but it draws about 8.7 amps from a 12 volt battery.

Drawing a lead acid battery all the way down can significantly reduce the life. 50% is the sweet spot for deep cycle and I would not go below 80% on a regular basis. Designing for 50% your 100 amp-hr battery holds 600 watt-hrs (100x12/2)of useable juice. A 104 watt pump would run for about five hours(600/104). Two 104 watt pumps would run 150 minutes. That works out to a little over six days at 24 minutes per day.

I would plan on charging once a week for a deep cycle battery. If using an automotive starting battery charge twice a week.

The calcs are about the same for 104 watt DC. DC pumps may cost a little more and you may have to change brushes. However you save the cost of an inverter.

You may have trouble with your existing inverter with two AC pumps when you consider pump starting surge.

Worth1 · March 12, 2016

I just looked at a deep cycle battery almost just like the one he has and it will run 5 amps for almost 20 hours.
http://www.interstatebatteries.com/m...rine/deepcycle

PureHarvest · March 12, 2016

The pumps would be timed to not run at the same time regardless if I do AC or DC.

But I am now confused on daily usage in relation to my battery to run 2 pumps for 24 or 30 mins per day.

Worth1 · March 12, 2016

Quote:

Originally Posted by PureHarvest

The pumps would be timed to not run at the same time regardless if I do AC or DC.

But I am now confused on daily usage in relation to my battery to run 2 pumps for 24 or 30 mins per day.

Running them 24 minutes will take off 84 minutes a week or one hour and 24 minutes.

PureHarvest · March 12, 2016

Quote:

Originally Posted by Worth1

Running them 24 minutes will take off 84 minutes a week or one hour and 24 minutes.

And we're starting at 100?

Worth1 · March 12, 2016

Quote:

Originally Posted by PureHarvest

And we're starting at 100?

100 amp hours or hours of use.

https://www.google.com/url?sa=t&rct=...Xa4-WhwP1rOgDw

March 12, 2016	#32
zeuspaul Tomatovillian™ Join Date: May 2007 Location: North County, San Diego Posts: 419	I do the math a little differently. I prefer watts because a 104 watt pump is 104 watts no matter the source voltage. For example your 104 watt pump draws .9 amps from 120 volts but it draws about 8.7 amps from a 12 volt battery. Drawing a lead acid battery all the way down can significantly reduce the life. 50% is the sweet spot for deep cycle and I would not go below 80% on a regular basis. Designing for 50% your 100 amp-hr battery holds 600 watt-hrs (100x12/2)of useable juice. A 104 watt pump would run for about five hours(600/104). Two 104 watt pumps would run 150 minutes. That works out to a little over six days at 24 minutes per day. I would plan on charging once a week for a deep cycle battery. If using an automotive starting battery charge twice a week. The calcs are about the same for 104 watt DC. DC pumps may cost a little more and you may have to change brushes. However you save the cost of an inverter. You may have trouble with your existing inverter with two AC pumps when you consider pump starting surge. Last edited by zeuspaul; March 12, 2016 at 05:01 PM. Reason: added: at 24 minutes per day

March 12, 2016	#33
Worth1 Tomatovillian™ Join Date: Feb 2006 Location: Den of Drunken Fools Posts: 38,539	I just looked at a deep cycle battery almost just like the one he has and it will run 5 amps for almost 20 hours. http://www.interstatebatteries.com/m...rine/deepcycle

March 12, 2016	#34
PureHarvest Tomatovillian™ Join Date: Mar 2014 Location: Mid-Atlantic right on the line of Zone 7a and 7b Posts: 1,369	The pumps would be timed to not run at the same time regardless if I do AC or DC. But I am now confused on daily usage in relation to my battery to run 2 pumps for 24 or 30 mins per day.