Page 1 of 4 1234 LastLast
Results 1 to 10 of 32
  1. #1
    Platinum Member
    Join Date
    Mar 2005
    Posts
    696
    Location
    Richfield, Wi
    Tractor
    Resident Architect

    Default What size solar panel to maintain batteries?

    I'm looking to purchase a solar panel to keep by batteries at full charge for a piece of equipment which is stored in a remote location. This piece of machinery has a diesel 12v engine and two batteries. Typically, I'd use a 3amp battery maintainer. The solar panels are not rated in amps, but watts. How many watts do I need to maintain these batteries? In the winter, this panel will be covered with snow, so please take that into consideration. I'm currently thinking about a 15watt panel, but it says that a controller is required. When do I need a controller and why?
    Turbo Yanmar 1110d, 4wd, powershift, kwick-way loader SOLD
    1988 Waldon 5100, Cummins 4b SOLD
    1999 Gehl 6635

  2. #2
    Veteran Member
    Join Date
    May 2002
    Posts
    1,119
    Location
    Warrenton MO
    Tractor
    JD4100 Hydro

    Default

    Your 3 A 12V battery maintainer would be 36 watt max output. So if it had been sufficient in the past, I'd look for a 36 W panel. That doesn't take snow cover into account.
    Shouldn't you be at work?

  3. #3
    Elite Member
    Join Date
    Jan 2010
    Posts
    3,461
    Location
    Oklahoma
    Tractor
    JD cut

    Default Re: What size solar panel to maintain batteries?

    A straight solar panel with no controller will continue to charge the battery even when it is at full charge, and end up overcharging it.

  4. #4
    Epic Contributor Soundguy's Avatar
    Join Date
    Mar 2002
    Posts
    48,804
    Location
    Central florida
    Tractor
    ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC

    Default Re: What size solar panel to maintain batteries?

    in the end.. just about ANY positive current flow will keep a battery topped off. all you need to do is overcome quiescent discharge, which is typically in the milliamps at best.

    I used to use one of those 9$ harbor freight panels that has a cig lighter adapter on it. thin is the size of a shoe box lid.. it kept my tractor batteries topped all year with -0- use in some cases.

    snow will block it till it melts off.. it won't snow forever though...

    soundguy

  5. #5
    Platinum Member Monster5601's Avatar
    Join Date
    May 2010
    Posts
    516
    Location
    Oakland, MI
    Tractor
    Kubota B3030 R4 Tires

    Default Re: What size solar panel to maintain batteries?

    Quote Originally Posted by greasemonkeyok View Post
    A straight solar panel with no controller will continue to charge the battery even when it is at full charge, and end up overcharging it.
    That depends on the output voltage of the panel. If the panel's voltage is below the battery voltage, there would not be a current flow.
    Bob, n8zcc

    Kubota B3030 with R4s
    LA403, 60" bucket with hooks, bolt-on tooth bar, ratchet rake
    BH76 with 16" bucket and thumb
    Kubota Pallet Folks
    Bush Hog 35-06 72" Rear Blade
    Bush Hog SBX60 Box Blade
    Bush Hog Razorback RZ160
    Kubota ZD323-60
    Kubota RTV900 with Curtis hydraulic angle plow

  6. #6
    Platinum Member Monster5601's Avatar
    Join Date
    May 2010
    Posts
    516
    Location
    Oakland, MI
    Tractor
    Kubota B3030 R4 Tires

    Default Re: What size solar panel to maintain batteries?

    Quote Originally Posted by Cord View Post
    I'm looking to purchase a solar panel to keep by batteries at full charge for a piece of equipment which is stored in a remote location. This piece of machinery has a diesel 12v engine and two batteries. Typically, I'd use a 3amp battery maintainer. The solar panels are not rated in amps, but watts. How many watts do I need to maintain these batteries? In the winter, this panel will be covered with snow, so please take that into consideration. I'm currently thinking about a 15watt panel, but it says that a controller is required. When do I need a controller and why?
    Look for a panel that can supply at least 12.6 volts DC, this is the threshold voltage of a fully charged lead acid battery. As far as current needs, parasitic loss of a typical lead acid battery depends on the type of battery and temperature, lead acid batteries have a parasitic loss somewhere between 1% to 60% rate per month. The warmer the temperature the battery is stored at increases the parasitic loss rate.

    A panel that can produce between 12.6 and 14 volts DC with a current of a few hundred milli-amps will keep a lead acid battery topped off, provided the panel has adequate time exposure to the of light needed to produce power and there is no other current draw on the battery.
    Bob, n8zcc

    Kubota B3030 with R4s
    LA403, 60" bucket with hooks, bolt-on tooth bar, ratchet rake
    BH76 with 16" bucket and thumb
    Kubota Pallet Folks
    Bush Hog 35-06 72" Rear Blade
    Bush Hog SBX60 Box Blade
    Bush Hog Razorback RZ160
    Kubota ZD323-60
    Kubota RTV900 with Curtis hydraulic angle plow

  7. #7
    Platinum Member
    Join Date
    Dec 2006
    Posts
    705
    Location
    Columbus, Georgia
    Tractor
    Kuborta B2400, L2900, L4330; Caterpillar D3B, John Deere 455D

    Default Re: What size solar panel to maintain batteries?

    I have two 15watt Battery Minder solar chargers that I got from RVupgrades online. One is attached to a John Deere 455D with two 12 volt batteries and one is attached to a Caterpillar D3B with two 12 volt batteries. Both work well, and the price is the best I could find for a panel and controller. I think one system would work for both machines, but they are located in different places so I got one for each.

  8. #8
    Elite Member Redneck in training's Avatar
    Join Date
    Nov 2008
    Posts
    2,789
    Location
    South Central Iowa
    Tractor
    TYM 330 HST with FEL

    Default Re: What size solar panel to maintain batteries?

    Quote Originally Posted by Cord View Post
    I'm looking to purchase a solar panel to keep by batteries at full charge for a piece of equipment which is stored in a remote location. This piece of machinery has a diesel 12v engine and two batteries. Typically, I'd use a 3amp battery maintainer. The solar panels are not rated in amps, but watts. How many watts do I need to maintain these batteries? In the winter, this panel will be covered with snow, so please take that into consideration. I'm currently thinking about a 15watt panel, but it says that a controller is required. When do I need a controller and why?
    http://www.amazon.com/Sunforce-50032.../dp/B0006JO0X8
    Here is one.

  9. #9
    Platinum Member RPW's Avatar
    Join Date
    Aug 2009
    Posts
    757

    Default

    You can get an inexpensive 5w panel and keep the battery topped off. I use one on my flatbed trailer to keep the winch battery (deep cycle) charged. Works great and does not require a controller. And if you orient it to the south equal to your latatude (sp.) the snow shouldn't be a problem.
    2008 JD 5103, FEL, 6' Frontier, 6' HD boxblade, 7' Landscape rake, More impliments to come, Bobcat (clark) 742 SS.

  10. #10
    Super Member Gary Fowler's Avatar
    Join Date
    Jun 2008
    Posts
    7,916
    Location
    Bismarck Arkansas
    Tractor
    2009 Kubota RTV 900, 2009 Kubota B26 TLB & 2010 model LS P7010

    Default Re: What size solar panel to maintain batteries?

    I had a couple of 12 volt 15 watt panels and lent one to my brother in law to charge the battery on his Mule gate opener. It is patched in direct to the 12volt gate opener battery without a controller and has been in service for over 2 years and still works as required. I dont think these low wattage panels will overcharge a 12 volt battery.
    2010 LS P-7010C 20F/20R gear tractor & FEL, 2009 Kubota B 26 TLB, RTV 900 Kubota,17 foot Lund boat with 70HP motor, 2012-20 ft 12k GVW trailer, 2011- 52" Craftsman ZTR mower, 2013 Ferris Zero Turn, 3 weed whackers, pressure washer, leaf blowers, 7 foot bush hog, 8 foot landscape rake , 8 foot 3 PH disc, 2 row cultivator, 350 amp Miller AC/DC welding machine and all the tools needed to keep them all repaired and running.

Page 1 of 4 1234 LastLast

Similar Threads

  1. What's the biggest size tractor you would use to mow with?
    By Piston in forum Buying/Pricing/Comparisons
    Replies: 40
    Last Post: 10-11-2011, 01:12 PM
  2. Solar Electric Project
    By hayden in forum Projects
    Replies: 113
    Last Post: 09-16-2008, 02:20 AM
  3. Solar Battery Charger... ?
    By Dave___in___CT in forum Customization
    Replies: 18
    Last Post: 01-17-2004, 08:10 PM
  4. Generator FAQ?
    By MrP in forum Rural Living
    Replies: 25
    Last Post: 03-14-2003, 06:00 PM
  5. Tires tire size/ratio, replacement discussion, big repost
    By BrettFF205D in forum Yanmar
    Replies: 3
    Last Post: 03-24-2002, 09:38 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2014 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.