Max amp dc to dc charger for 5.4 owners

[posplayr]

Greg , I agree that the Renogy has a rather simplistic control setup but as I recall many of the more sophisticated options are generally for marine application where the price points are substantially above these cheaper options.

Many people have been trying to make the Renogy 40 amp DC-DC work especially after you get above 200 amp-hr in haus bat. A couple years ago I saw a ytuber specifically mention going for 20 amp unit vs 40 amp for the specific consent of burning up the alternator.

Call me one of the skin flints for going with the Renogy, but I also have an adversion to complex integrated controls where a whole family of products from one vendor are required.

[posplayr]

Greg, I just looked at this Victron dc-dc and it says it operates down to 8.5v. From what you said before this does not apply to the boost charging range because the functionality you described would have thd charger shut down at say below 12v?


https://shop.pkys.com/Victron-Energy...iAAEgJiePD_BwE

[Scalf77]

That is a plain dc to dc converter not a their smart dc to dc charger.

- greg

[posplayr]

Originally Posted by Scalf77

That is a plain dc to dc converter not a their smart dc to dc charger.

- greg

This must be what you are talking about

https://www.victronenergy.com/upload/documents/Engine-on-detection-set-up-Orion-Tr-Smart-DC-DC-Charger-EN.pdf

[LSretired1]

posplayr, I also have a stock 5.4 and a Renogy 40 amp dc to dc charger (Not installed yet). Did you install your 3 way switch and thermal cut off switch and if so, how did it work?

[posplayr]

Originally Posted by LSretired1

posplayr, I also have a stock 5.4 and a Renogy 40 amp dc to dc charger (Not installed yet). Did you install your 3-way switch and thermal cut-off switch and if so, how did it work?

Sorry I have not. The DIY LiFe battery got more involved and now I have crashed the front of the van so this has been set back pretty far.


https://diysolarforum.com/threads/di...4/#post-437407


I redrew the switch setup. It is simply a convenient way to control both power control lines to the renogy. What I labeled as +12V_RUN could be instead what is described in the manual coming right off the back of the alternator.

Generally, if I were to do a colder start to the vehicle, I would switch off the charging "O"=OFF. Leave it in this position when you stop the vehicle.

Once underway in town use the "I" = "20 amp charging".

Once on the freeway, you can safely go to "II" ="40 amp charging".

Otherwise, you just monitor the voltage on your dash and the Haus battery voltage that you can optionally install so you can read it while driving.

I simplified the diagram to eliminate the Temperature cutoff. The truth table is on the right-hand side. The only complication is the diode you would need to add to get the correct logic.

Alternatively, add the Temperature control (see original drawing). That is pretty simple as well if you can wire an automotive relay it.

Here are some garden variety diodes that you can put right in line with a piece of wire and a section of shrink tubing. You could buy smaller 1 amp diodes but there are physically more robust and you can manhandle them without ripping the device apart.

For Diode logic like this, there is very little current flowing so the 5A is fine. If you want something else that needs 10A then you could use those just as well. The band on the device indicates the point of the triangle or the cathode on the diode. These are just easier to solder to 14-16GA wire.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Note: I added the page from the manual for controlling D+. This alternator output would be the +12V_RUN on my schematics which is what powers the double rocker switch. (With the temperature control option the relay provides the power to the switch and is cut out when the thermal switch activates)
Essentially this allows you to interrupt the D+ signal (which is required to start DC-DC charging) from the alternator and control it as circumstance might dictate.

Also, It was not my own plan to wire the +12V_RUN from the alternator as I have already identified the HOT key ON wire in the steering console in the multi-switch connector.

If there is some additional functionality you can pull from the alternator then you can do as Renogy suggests.

[Lcavalletti]

SO I have now installed a switch to turn on or off the renogy Dc to dc charger. Until the time that I upgrade the stock alternator ( when mine craps out)

The switch works great, I turn it on at highway speeds and off at idle. That is if I need to charge the battery. Right now the battery stays charged with solar alone.

So that will be my solution here until something changes. I just bought a 3000 renogy pure sine inverter now to run ca coffee maker and an induction cooktop in the new kitchen. Will report how that all goes, I opted to now buy an inverter charger as I just dont see myself needing it with the DC to dc charger.

[posplayr]

Originally Posted by Lcavalletti

The switch works great, I turn it on at highway speeds and off at idle. That is if I need to charge the battery. Right now the battery stays charged with solar alone.

So that will be my solution here until something changes.

With 300 amp-hr you are probably not depleting your battery bank too much and the solar is sufficient to make up for your usage.

While it is a simple solution using a switch, there is no simple fully automatic control of the DC-DC unless you monitor voltages, currents, temperature and RPM. So the switch gives you complete control albeit with the requirement to be a little diligent about load controls.