EcoRenovator  

Go Back   EcoRenovator > Improvements > Solar Power
Advanced Search
 


Blog Register 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read


Reply
 
Thread Tools Display Modes
Old 03-21-10, 11:34 PM   #1
msirach
Lurking Renovator
 
Join Date: Feb 2009
Location: Southern Illinois
Posts: 17
Thanks: 0
Thanked 0 Times in 0 Posts
Default Have Batteries:Need System

I have been collecting parts for a backup system for home power. The backup system that I'm shooting for will also power a 43 watt cfl street lamp each night, a 30w 400gpm fountain pump during the summer, and charge my electric Black and Decker mower (29w).

The batteries came from two UPS systems at work for FREE. A couple batteries tested poor so they replaced all of them. The ones that I took all tested 80 Mhos or more. They are C&D Technologies: 12 @75ah and 12 @88ah for a total of 1956ah.

To backup the backup, I have a Honda EU2000I. $39 cash in the Honda generator/inverter made it a great purchase. (Purchased with a 14 months of safety gift cards from work.)

A Black & Decker store gave a super special deal for $69 which was about 25% of the normal price on a Vector 2000 watt 12v to 120v inverter.

Do I really need 2/0 battery cables? Would #2 work?

I plan on buying new pv panels and charge controller. Cable may be found used and I will have to buy new ring connectors.

Best bang for the buck on pv panels and charge controller?


Last edited by msirach; 03-22-10 at 10:29 PM.. Reason: added watts
msirach is offline   Reply With Quote
Old 03-22-10, 06:54 AM   #2
Daox
Administrator
 
Daox's Avatar
 
Join Date: Aug 2008
Location: Germantown, WI
Posts: 5,513
Thanks: 1,154
Thanked 374 Times in 305 Posts
Default

Welcome to the site msirach.

I think that the #2 will work just fine. You'll have more losses through that cable, but it won't be bad.

Do you know how much power your charger and water fountain use while on?
__________________
Current project -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
&
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Daox is offline   Reply With Quote
Old 03-22-10, 10:30 AM   #3
msirach
Lurking Renovator
 
Join Date: Feb 2009
Location: Southern Illinois
Posts: 17
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Charger is 29 Watts, lamp is 43 Watts, pump is 20watts(I think).
msirach is offline   Reply With Quote
Old 03-22-10, 10:54 AM   #4
Daox
Administrator
 
Daox's Avatar
 
Join Date: Aug 2008
Location: Germantown, WI
Posts: 5,513
Thanks: 1,154
Thanked 374 Times in 305 Posts
Default

Oh, those loads are a fair amount smaller than I was thinking. You shouldn't have any problem running those all night. A little extra capacity wouldn't hurt though. You'd be running them down to ~50% every night (all three loads on). The less deeply you cycle the batteries the longer they will last. However, your setup now is probably fine.

For your other components, you should check out some other posts in this subforum. Xringer has been looking at a lot of this stuff very recently and I believe has just ordered some Kaneka panels for a pretty good price. He also has a few posts/threads on the other components you're looking for.
__________________
Current project -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
&
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Daox is offline   Reply With Quote
Old 04-04-10, 09:30 AM   #5
OffGridKindaGuy
Hi-Tech Hillbilly
 
OffGridKindaGuy's Avatar
 
Join Date: Mar 2010
Location: Ohio
Posts: 97
Thanks: 1
Thanked 16 Times in 15 Posts
Send a message via AIM to OffGridKindaGuy
Default

Quote:
Originally Posted by msirach View Post
Charger is 29 Watts, lamp is 43 Watts, pump is 20watts(I think).
Are these 120 v.a.c. loads ran via the inverter from your battery?

29+43+20= 92 watts a.c. (Demand from the inverter)

For every 1 amp demand from an inverter requires 10 amps from the battery @ 12 volts d.c. (Not including inverter losses)

92 watts @ 120 v.a.c. = 0.76 amps

92 watts @ 12 v.d.c. = 7.66 amps

Total aHr. reserve of your battery.. 1956 aHr.

Divide by 4 = *489 aHr. (25% of the total for 25% discharge level) *Never discharge your battery any lower than 20-25% of the total capacity. (11.8 volts)

With your given load, (7.66 amps) you should be able to operate things for 63.8 hrs. with fully charged, new condition batteries. (Don't forget ya gotta replace this used energy )

The closer you keep the inverter to the battery, the smaller gauge wire will be needed. With less than a 10 amp load, you could get by with 12 ga. wire within 10 ft. of the battery BUT if you plan to operate other things with the inverter, you'd better plan for heaver wire.

What's the "Grand Plan"? Are these the only items you plan to operate with this set up?
__________________
If it don't, I'll always think it shoulda..
OffGridKindaGuy is offline   Reply With Quote
Old 04-04-10, 12:25 PM   #6
msirach
Lurking Renovator
 
Join Date: Feb 2009
Location: Southern Illinois
Posts: 17
Thanks: 0
Thanked 0 Times in 0 Posts
Default

OffGridKindaGuy: Thanks for the detail.

Yes, I am running directly from the inverter now.

The inverter is 24" from the connection to the battery. The inverter directions "require" 2 #4 cables for the positive and 2 for the negative. I connected it with 1 #6 and the losses through the inverter seem to be great during the day. I have it powering ONLY the yard light which is pulling 37-39 watts per Kill A Watt.

If I leave it on during the day, I gain very little charge. For temporary, I have a Harbor Freight 45 watt system charging. If I leave the inverter on, very little voltage is gained during the day.

I haven't ordered the PV panels yet. As I mentioned previously, I am shooting for the "best bang for the buck!" $1 to 1.5k is what I'm looking out.
msirach is offline   Reply With Quote
Old 04-04-10, 04:46 PM   #7
Xringer
Lex Parsimoniae
 
Xringer's Avatar
 
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,897
Thanks: 111
Thanked 248 Times in 228 Posts
Default

You need to add up your kWh used over night, so you can come up with
an adequate size for your PV array.. If you have 5 hours of good sun on the PV
array and it's a 100 watt panel (0.1kw), it's going to put a possible 0.5kWh charge into the batteries..

And, if it's cloudy for a couple of days, will your pack be able to supply the loads?
Or will you be able to use the grid or the Honda to charged up the pack?

I would buy at least enough PV to replace all the juice lost during the night,
plus about 25%, for losses and in case of clouds..

Here's a pretty nice panel store.. Solar Panels

I'm looking at some of those cheaper thin-film panels that are coming out in May.
Not sure if I'll get them yet, since they are so large and heavy..

Now that that the floods have done a job on my basement, we are looking
at major cost to repair, add pumps etc..
Xringer is offline   Reply With Quote
Old 04-04-10, 08:16 PM   #8
OffGridKindaGuy
Hi-Tech Hillbilly
 
OffGridKindaGuy's Avatar
 
Join Date: Mar 2010
Location: Ohio
Posts: 97
Thanks: 1
Thanked 16 Times in 15 Posts
Send a message via AIM to OffGridKindaGuy
Default

Quote..
"I have a Harbor Freight 45 watt system charging."

Let's figure from here..

According to the specs, the "working" voltage is 14.5/15 volts. The system is rated at 45 watts. The total amperage of this system is 3 amps @ 15 volts.

During perfect conditions and correct angle, 15 aHr. could be collected during a day. (5 hr. peak charge period) Your battery shouldn't be much larger than 4 times this amount (60 aHr.) to achieve full charge in a days time. Your total usage should be kept within 15 aHr. in a 24 hr. period. The energy collected before 9:30 am and after 2:30 pm will cover the internal losses in the battery. (20%)

"I have it powering ONLY the yard light which is pulling 37-39 watts per Kill A Watt."

Houston.. We have a problem..

We'll round to 38 watts @ 120 v.a.c. = .316 amps

@ 12 volts = 3.16 amps (Through the inverter)

If you are only using the Harbor Freight system to charge with, you can only operate your outdoor light "safely" for around 5 hrs. max.

If you have more than 60 aHr. reserve of battery, you'll never gain full charge which will destroy your batteries over time. If you have all of those batteries connected, that's not a good thing. I would only use one of the 75 aHr. batteries by itself..
__________________
If it don't, I'll always think it shoulda..
OffGridKindaGuy is offline   Reply With Quote
Old 04-04-10, 09:20 PM   #9
Xringer
Lex Parsimoniae
 
Xringer's Avatar
 
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,897
Thanks: 111
Thanked 248 Times in 228 Posts
Default

I wonder if using LED lamps would better than a CFL?

LED MR16 Light Bulb, Warm White, 4.5 Watt, 12vDC - Replaces a 50W Halogen
Xringer is offline   Reply With Quote
The Following User Says Thank You to Xringer For This Useful Post:
classradiance (09-25-12)
Old 04-04-10, 10:50 PM   #10
msirach
Lurking Renovator
 
Join Date: Feb 2009
Location: Southern Illinois
Posts: 17
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by Xringer View Post
I wonder if using LED lamps would better than a CFL?

LED MR16 Light Bulb, Warm White, 4.5 Watt, 12vDC - Replaces a 50W Halogen
I have purchased several led's as they have became available in my area and to date, I have wasted a lot of money. I have not purchased any of the LED's for $100 or more, but I have tried some that should have performed well for the price.

The CFL is a 200 watt equivalent and does a great job in the back yard.

msirach is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:23 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design