Jump to content


Photo

MPPT + DC-DC = (cheap) B2B

Solar DC-DC B2B Hack Battery Charger

  • Please log in to reply
12 replies to this topic

#11 rando

rando

    Senior Member

  • Members
  • 1,113 posts
  • LocationColorado

Posted 04 October 2019 - 08:23 PM

I honestly can't say why you are only getting 2-5A into the battery - which MPPT charger do you have and are you sure the settings are correct?  

 

You do not need to ground the output of the DC-DC converter to the frame - it should just go into the solar panel terminals on the charge controller.   Do you also have a solar panel hooked up to the input to the input?


  • 0

2016 Fleet Flatbed

2016 Toyota Tacoma


#12 wiredinoc

wiredinoc

    Newbie

  • Members
  • Pip
  • 3 posts

Posted 04 October 2019 - 10:09 PM

OK that's how I'm hooked up. What did you mean by a common ground then?

 

I do have a solar panel but its the suitcase type. I only unpack it when parked and disconnected from the vehicle.

 

I haven't made any changes to the MPPT, solar works fine. I'm wondering if the 48v is too high. I just ordered that 24v 20 amp model you posted to give it a shot.

 

Victron 100/20 mppt


  • 1

#13 rando

rando

    Senior Member

  • Members
  • 1,113 posts
  • LocationColorado

Posted 23 February 2020 - 08:38 PM

Quick update on this project.   Used this for a week out in the desert in some overcast conditions and it worked beautifully.   I set the charge controller for 20A charge current, and after a night of furnace use and charging laptops I managed to pull nearly 60Ah out of the battery.  Driving for ~3 hours the next day I was back to 95% full, then the solar did the rest.   I saw no issues pushing 20A through the charge controller (and 12A through the DC-DC converter) for hours at a time, and when I stopped the solar charging also worked just as it should. 

 

Anyway, this is officially a proven success.


  • 0

2016 Fleet Flatbed

2016 Toyota Tacoma






Also tagged with one or more of these keywords: Solar, DC-DC, B2B, Hack, Battery Charger

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users