OUR VIDEOS GALLERY MEMBER SPONSORSHIP VENDOR SPONSORSHIP

User Tag List

Page 1 of 3 123 LastLast
Results 1 to 10 of 21

Thread: Small Solar Maintenance Charger Advice Pretty Please [emoji120]

  1. #1
    ......... MB's Avatar
    Join Date
    Nov 2015
    Location
    Yarra Valley
    Posts
    5,906
    Thanks
    14,935
    Thanked 7,043 Times in 3,268 Posts
    Mentioned
    341 Post(s)
    Tagged
    0 Thread(s)

    Small Solar Maintenance Charger Advice Pretty Please

    G’day NP.com.au Team,

    Hoping for some advice please on happy/safe usage of anyones experienced purchase of small solar maintenance chargers?

    Needing to purchase a couple for 12v batteries around the property on contraptions that have slight parasitic drain occuring.

    Did purchase a cheapo version years ago for a diesel dam pump and found its battery swollen/cactus after checking some months later.

    Assuming the cheapo ones regulator thingymebob failed and destroyed a $200 battery so hoping for that to not happen again :-(

    Many thanks
    Mark



    Sent from my iPhone using Tapatalk

  2. # ADS
    Circuit advertisement
    Join Date
    Always
    Location
    Advertising world
    Posts
    Many

     

  3. #2
    Daily Lurker rusty_nail's Avatar
    Join Date
    Jan 2012
    Location
    Yarra Valley, Vic
    Posts
    5,306
    Thanks
    7,335
    Thanked 5,098 Times in 2,234 Posts
    Mentioned
    64 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by MB View Post
    G’day NP.com.au Team,

    Hoping for some advice please on happy/safe usage of anyones experienced purchase of small solar maintenance chargers?

    Needing to purchase a couple for 12v batteries around the property on contraptions that have slight parasitic drain occuring.

    Did purchase a cheapo version years ago for a diesel dam pump and found its battery swollen/cactus after checking some months later.

    Assuming the cheapo ones regulator thingymebob failed and destroyed a $200 battery so hoping for that to not happen again :-(

    Many thanks
    Mark



    Sent from my iPhone using Tapatalk
    I bought one from Jaycar years ago, have always had I plugged in to my camper never caused issues with the batteries and I think it's probably been around for about 10 years

    Sent from my SM-G965F using Tapatalk
    I got red dust in my veins.

    Check out My Rig here: Broken

    Pics of Forum trips I've Been on:
    Pizza at AB's - 2012 Knockwood - 2013 Krissos Place Australia Day - 2015 Pizza at AB's - March 2015 Pizza at AB's - May 2015 Dargo - 2015 Newnes - 2016

    WARNING: Towballs used for recoveries can, and do kill people and damage property.

  4. The Following User Says Thank You to rusty_nail For This Useful Post:

    MB (11th October 2020)

  5. #3
    Legendary GQtdauto's Avatar
    Join Date
    Dec 2016
    Location
    Northeast Victoria
    Posts
    3,008
    Thanks
    5,082
    Thanked 1,872 Times in 1,252 Posts
    Mentioned
    41 Post(s)
    Tagged
    0 Thread(s)
    You would only need a small panel as pictured by rustynail and if your worried about the regulator get the smallest VictronConnect regulator .
    That way you can check on the battery's last 30 days of data using your phone if your in Bluetooth range , no need for a multimeter .

  6. The Following User Says Thank You to GQtdauto For This Useful Post:

    MB (11th October 2020)

  7. #4
    ......... MB's Avatar
    Join Date
    Nov 2015
    Location
    Yarra Valley
    Posts
    5,906
    Thanks
    14,935
    Thanked 7,043 Times in 3,268 Posts
    Mentioned
    341 Post(s)
    Tagged
    0 Thread(s)
    I do like the sound of that Thanks Rob, Welcome Back Old Mate!


    Sent from my iPhone using Tapatalk

  8. #5
    Patrol God
    Join Date
    May 2013
    Posts
    6,027
    Thanks
    4,740
    Thanked 4,785 Times in 2,683 Posts
    Mentioned
    143 Post(s)
    Tagged
    1 Thread(s)
    Look up / Talk to Low Energy Developments Marko mate.
    They have various small sized panels for various purposes and fittings , chargers etc... They know solar !
    All my solar needs go there.

    Sent from my Pixel 3a XL using Tapatalk
    2005 TD42TI

  9. The Following User Says Thank You to Hodge For This Useful Post:

    MB (12th October 2020)

  10. #6
    I am he, fear me the evil twin's Avatar
    Join Date
    Jun 2010
    Location
    W.A. (wandering aust)
    Posts
    6,138
    Thanks
    887
    Thanked 6,457 Times in 3,233 Posts
    Mentioned
    41 Post(s)
    Tagged
    1 Thread(s)
    If the panel max output is below one amp (say you have a 10 watt panel) and a battery above about 70 amp hours just hook the panel straight to the battery.

    The internal resistance of the battery acts as a load and effectively regulates the panel as good or better than a separate Reg.

    I have small panels/ no reg direct to Battery on my water feature pump (5 watt to 30 AH battery), maint. charging my boat (20 watt to 2 x 90 AH) and some garden lighting .

    The rule of thumb is 1:100 IE 1 amp Panel current per 100AH of battery capacity (IMHO that is conservative and I work on less) but using that ratio a standard 10 watt panel of 0.6 amp max current into 60 AH lead acid battery doesn't need any form of Reg
    Last edited by the evil twin; 12th October 2020 at 11:23 AM.
    Dolphins are so smart that within a few weeks of captivity, they can train people to stand on the very edge of the pool and throw them fish.

  11. The Following 2 Users Say Thank You to the evil twin For This Useful Post:

    MB (12th October 2020), rusty_nail (12th October 2020)

  12. #7
    ......... MB's Avatar
    Join Date
    Nov 2015
    Location
    Yarra Valley
    Posts
    5,906
    Thanks
    14,935
    Thanked 7,043 Times in 3,268 Posts
    Mentioned
    341 Post(s)
    Tagged
    0 Thread(s)
    Some great advice, thank you kindly Gentlemen


    Sent from my iPhone using Tapatalk

  13. #8
    ......... MB's Avatar
    Join Date
    Nov 2015
    Location
    Yarra Valley
    Posts
    5,906
    Thanks
    14,935
    Thanked 7,043 Times in 3,268 Posts
    Mentioned
    341 Post(s)
    Tagged
    0 Thread(s)
    Confirming did the old ‘Jaycar Click & Quick Collect’ for a couple of Rusty_Nails & PeeBees phone advice panels on the way home from work.


    20W/1.15A direct onto the tractor battery (Lead Acid 160 RC Minutes) if I understand everyone’s thankful advice should loosely convert hopefully to 100+AH safely?

    Will look towards a third flash bluetooth type remote version for dam pump down in the valley once time & money permits thanks heaps again Gentlemen


    Sent from my iPhone using Tapatalk

  14. The Following 2 Users Say Thank You to MB For This Useful Post:

    Hodge (13th October 2020), PeeBee (13th October 2020)

  15. #9
    Expert pollenface's Avatar
    Join Date
    Nov 2019
    Location
    Perth
    Posts
    136
    Thanks
    13
    Thanked 55 Times in 39 Posts
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I wouldn't connect any panel straight to a battery without a regulator - at night time the current flows the other way.

    solar panel ==> regulator ==> battery

    Rule of thumb is to pick a regulator that is 125% the short circuit current/Isc of the solar panel (in offgrid use).

    The Isc of your 20W panel is 1.21A so would require a regulator that is at least 1.5A

    Cheap PWM regulators are basically just a voltage sensing switch which usually cut out around 14.6v and are "okay" for small jobs (10-20w for maintenance). Such regulators can be had for around $10-$15 a piece.

    Good quality PWM regulators (Epever/morningstar/projecta/etc) are durable and usually do a 3-stage charge (bulk/absorption/float) and have preset charging parameters for different battery types (sealed/gel/wet). When used correctly they will keep your batteries good for many years. They will set you back around $40-$60.

    If you're looking on ebay, many PWM regs are mislabled as MPPT. If what's being advertised appears to be physically small and around $15, they're not MPPT (MPPT is not something you need to worry about for what you want to do).
    Last edited by pollenface; 14th October 2020 at 12:00 AM.
    2008 CRD Wagon, 191,000kms and counting....

  16. The Following User Says Thank You to pollenface For This Useful Post:

    MB (15th October 2020)

  17. #10
    I am he, fear me the evil twin's Avatar
    Join Date
    Jun 2010
    Location
    W.A. (wandering aust)
    Posts
    6,138
    Thanks
    887
    Thanked 6,457 Times in 3,233 Posts
    Mentioned
    41 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by pollenface View Post
    snip... I wouldn't connect any panel straight to a battery without a regulator - at night time the current flows the other way.
    Pls excuse the snip.

    That is what the "blocking diode" is for, to prevent reverse current flow when the sun isn't shining.

    Also, a PWM Reg will reduce the effective rating of the panel by about 1/4 to a 1/3rd.

    Panel direct to battery is very common in many standby applications.
    For example there are no regs on all of the small maintenance charging panels you see for vehicles that you sit on the dash and plug into the ciggy lighter
    It is also why most Panels under 20 watts come with alligator clips and not MC style solar connectors.
    The battery voltage on my boat sits at approx 12.8 off charge and rises to 12.9 when the panel is in full sun.

    Effectively the battery is appearing as a huge capacitive load to the panel and in practical use the system will perform better than a PWM reg system with the non-regulated panel output running close the the max power knee of the performance curve IE max current output so almost like it has an invisible MPPT Reg.

    BUT... the Panel output has to be such that the load of the fully charged battery still draws a current flow so as long as you don't put too large a panel in place and the panel has a blocking diode it should have no noticeable adverse effect to the battery life.

    I do, however, totally agree that a panel without a blocking diode won't work as desired and once you get up in solar panel power to battery capacity past a certain point you have to use a Reg.
    Last edited by the evil twin; 14th October 2020 at 11:04 AM.
    Dolphins are so smart that within a few weeks of captivity, they can train people to stand on the very edge of the pool and throw them fish.

  18. The Following 4 Users Say Thank You to the evil twin For This Useful Post:

    MB (15th October 2020), MudRunnerTD (26th October 2020), pollenface (15th October 2020), rusty_nail (14th October 2020)

Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •