Possible to charge main battery using solar and NL25 dc-dc?





Results 1 to 11 of 11
  1. #1
    Join Date
    Aug 2018
    Location
    Port Louis
    Posts
    35
    Thanked: 12

    Default Possible to charge main battery using solar and NL25 dc-dc?

    Wondering of its possible to use my NL25 dc-dc system (with solar) to charge the main battery once Aux is full? Is there a way to wire that up to automatically switch over? I dont think the NL25 system does this type of reverse charging automatically.

    thanks

    Mulva

  2. #2
    Join Date
    Apr 2016
    Location
    Johannesburg
    Age
    69
    Posts
    396
    Thanked: 62

    Default Re: Possible to charge main battery using solar and NL25 dc-dc?

    What is the main battery used for? Is it to power the charger if there is no other supply?
    It looks like in a caravan/trailer mode with PV panels it doesn't need a main battery..
    Please confirm if this is the case..

  3. #3
    Join Date
    Aug 2018
    Location
    Port Louis
    Posts
    35
    Thanked: 12

    Default Re: Possible to charge main battery using solar and NL25 dc-dc?

    Quote Originally Posted by Richard Mackay View Post
    What is the main battery used for? Is it to power the charger if there is no other supply?
    It looks like in a caravan/trailer mode with PV panels it doesn't need a main battery..
    Please confirm if this is the case..
    It's a simple dual battery system in my Defender. Main battery only used for starting and regular automotive features. Aux used for any overlanding accessories I have attached (led lighting, fridge, work lights). The NL25 is pretty straightforward - inputs from Main/alternator, Aux, ground and solar. The truck sits now and again with small battery drains from gps tracker and maybe other small parasitic drains. Main battery is also not in best shape anymore. It would be nice to be able to use the solar already topping up the Aux to keep Main charged

  4. #4
    Join Date
    Feb 2017
    Location
    Santa Cruz, CA
    Posts
    293
    Thanked: 205

    Default Re: Possible to charge main battery using solar and NL25 dc-dc?

    I have the NL25 DCDC too, and I also would LOVE this feature. Our vehicle is a dedicated overland vehicle, and goes long periods not being driven. Combined with the constant drain of the unavoidable CarTrack tracker, and it kills the start battery. Seem like it'd be great if the solar would switch over to the start battery if the aux battery was full.

    I'm going to install a manual switch, for when the vehicle in in storage, to accomplish this.

  5. The Following User Says Thank You to CalDriver For This Useful Post:


  6. #5
    Join Date
    Apr 2016
    Location
    Johannesburg
    Age
    69
    Posts
    396
    Thanked: 62

    Default Re: Possible to charge main battery using solar and NL25 dc-dc?

    The charger isn't designed to charge the main battery but you might be able to make a plan..
    You could swap the batteries to charge both. They also could be switched electrically with a changeover switch..

  7. The Following User Says Thank You to Richard Mackay For This Useful Post:


  8. #6
    Join Date
    Feb 2017
    Location
    Santa Cruz, CA
    Posts
    293
    Thanked: 205

    Default Re: Possible to charge main battery using solar and NL25 dc-dc?

    Quote Originally Posted by Richard Mackay View Post
    The charger isn't designed to charge the main battery but you might be able to make a plan..
    You could swap the batteries to charge both. They also could be switched electrically with a changeover switch..
    I haven't drawn it out yet, but I am thinking of one of these switches: https://www.bluesea.com/products/600...y_Switch_-_Red

  9. #7
    Join Date
    Apr 2016
    Location
    Johannesburg
    Age
    69
    Posts
    396
    Thanked: 62

    Default Re: Possible to charge main battery using solar and NL25 dc-dc?

    What is the main battery used for? Is it to power the charger if there is no other supply?
    If it's not essential then an easy plan is possible..

  10. #8
    Join Date
    Oct 2013
    Location
    Centurion
    Age
    63
    Posts
    1,492
    Thanked: 520

    Default Re: Possible to charge main battery using solar and NL25 dc-dc?

    Quote Originally Posted by CalDriver View Post
    I have the NL25 DCDC too, and I also would LOVE this feature. Our vehicle is a dedicated overland vehicle, and goes long periods not being driven. Combined with the constant drain of the unavoidable CarTrack tracker, and it kills the start battery. Seem like it'd be great if the solar would switch over to the start battery if the aux battery was full.

    I'm going to install a manual switch, for when the vehicle in in storage, to accomplish this.
    Is the logic of the NL25DC-DC not in such a way that if you have solar it will not charge via the main battery.

    If it is then one can charge the main battery via the NL25DC-DC (2nd bat not connected to NL25DC-DCwith solar to keep it full and use a bypass switch to connect the main and 2nd battery together to be kept full when the vehicle is not used.

    Can this work?

  11. #9
    Join Date
    Apr 2019
    Location
    Midrand
    Posts
    362
    Thanked: 569

    Default Re: Possible to charge main battery using solar and NL25 dc-dc?

    I had a few technical questions on the similar 40A DC-DC and e-mailed Nat Luna support - got a very prompt and VERY thorough, and technical, response from them. You might try that route to get it straight from the "horse's mouth" so to speak - I was very very impressed with their support.

  12. The Following User Says Thank You to heyyahhey For This Useful Post:


  13. #10
    Join Date
    Feb 2017
    Location
    Santa Cruz, CA
    Posts
    293
    Thanked: 205

    Default Re: Possible to charge main battery using solar and NL25 dc-dc?

    Quote Originally Posted by heyyahhey View Post
    I had a few technical questions on the similar 40A DC-DC and e-mailed Nat Luna support - got a very prompt and VERY thorough, and technical, response from them. You might try that route to get it straight from the "horse's mouth" so to speak - I was very very impressed with their support.
    Totally agree - NL support is excellent and knowledgable. Really impressed with them, and I've contacted them a few times.

  14. The Following User Says Thank You to CalDriver For This Useful Post:


  15. #11
    Join Date
    Jul 2019
    Location
    Houtbay
    Age
    63
    Posts
    32
    Thanked: 26

    Default Re: Possible to charge main battery using solar and NL25 dc-dc?

    Been considering something similar for my NL 25A DC-DC setup.
    A marine change-over switch would work but is expensive.
    Could use a DB type change-over switch if inside the vehicle and not under the bonnet - a bit cheaper.
    A few Brad-Harris plugs would also work - cheap but fiddly.
    My preferred approach and what I'll probably do is buy a solar controller and wire it directly between the panel and the main battery. This is simple and gives you redundancy if your DC-DC charger fails.
    2020 Landcruiser 79 DC V6
    2012 Prado 150VX V6

Tags for this Thread

Bookmarks

Posting Permissions

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