Max amp dc to dc charger for 5.4 owners

[posplayr]

Originally Posted by lashidalgo

I've been using this https://www.renogy.com/dcc50s-12v-50...ger-with-mppt/ for a little over a year in the PNW where it doesn't get that hot without any issues !, Sometimes at night I run my 30amp light bar, no problem

That 50A DC-DC Mppt has a different input and appears to be designed for smart Alternators whatever that means.

[lashidalgo]

Originally Posted by posplayr

That 50A DC-DC Mppt has a different input and appears to be designed for smart Alternators whatever that means.

That pin is optional, as long as you connect alt+ it WILL work

I have my panels and alternator connected to it, when my house battery is full it tops off my starter one which is pretty cool

Page 13 point #3 at the bottom of the page: https://www.renogy.com/content/RBC30...D1S-Manual.pdf

[Scalf77]

I believe the model of DC to DC the OP has chose to use is pretty simple. In that it merely relies on the ignition input to decide to operate. If the alternator is up and operating then it turn on the DC to DC charger. It does also have a current limiter which when invoked will cut the current in half. You could use that to determine if a 20 amp version would work.

My assumption is that he is seeing the lower voltages when the alternator is closer to idle. It really depends on what additional electrical loads one is running at the time this is happening. Remember the The surepower and B/S ACR would monitor voltage, if the voltage dropped below 12.8 volts the units would disconnect, thus reducing any load coming from the "house system".

This system does not have that protection, so you pretty much want to make sure that you have enough alternator power. Actually even with systems that have some protections the goal is to have enough power.

The 50 amp version that "lashidalgo" mentioned does not operate the same way. It operates much like a ACR , it will come on when the start battery voltage is above 13.2 volt and will disconnect when it is below 12.7 volts. It should also be noted that while this unit is a 50 amp unit, it shares 25 amp of solar and 25 amps of Dc to DC. I believe the max DC to DC is 25 amps.

There is also a connection on the 50 amp version for a "Smart Alternator". If this is hooked up, it will take the low voltage disconnect to 12 Volts. This is because smart alternators generally run at a lower voltage. These smart alternators are found on newer vehicles, such as my 2020 Transit.

I am not a big fan of the version of DC to DC the OP has, to many other better options out there. There are a couple of versions that will throttle themselves back if they are detecting low voltage input.

-greg

[neatvan]

Originally Posted by Scalf77

The 50 amp version that "lashidalgo" mentioned does not operate the same way. It operates much like a ACR , it will come on when the start battery voltage is above 13.2 volt and will disconnect when it is below 12.7 volts. It should also be noted that while this unit is a 50 amp unit, it shares 25 amp of solar and 25 amps of Dc to DC. I believe the max DC to DC is 25 amps.
-greg

I recently installed the DCC50S that "lashidalgo" mentioned. The documentation is confusing, but it can supply the full 50A from either solar or the alternator IF it only sees one source. If two sources are detected, it will limit solar to 25A and alternator to 25A for a total of 50A.

Another feature that is not documented well is the ability to limit the charge current. You can set the total charge current in increments of 10A, but my experience is you can only access this feature with the BT-2 bluetooth module and the app for your phone. This allowed me to set a safe charging current from my factory alternator!

Unfortunately, I believe this is the OPs model, and sadly, I couldn't find a bluetooth dongle for it to access similar current limiting features.
https://www.renogy.com/12v-40a-dc-to...ttery-charger/

[Scalf77]

Thanks for that information, it does make sense that it would supply the full 50.

-greg

[Lcavalletti]

I have retired my charger to now provide half the amperage. The LC input allows one to charge half the amperage. 40. Down to 20. I figure I’ll use the charger this way until the time comes to change my alternator. When I change that I’ll go with a higher amp alternator. Until then I’ll charge at a safe 20 amp. Starter battery now holds steady at 14.4 while charging even at idle.

I just can’t justify changing out a perfectly functioning alternator.

Now the question I have is how does one trickle charge the starter battery with solar so it’s always fully topped up. While connected to house battery. Would feel a lot better if my starter battery was at 12.7 instead of 12.3 or lower all the time. Would be a nice feature

[posplayr]

Originally Posted by Lcavalletti

Now the question I have is how does one trickle charge the starter battery with solar so it’s always fully topped up. While connected to the house battery. Would feel a lot better if my starter battery was at 12.7 instead of 12.3 or lower all the time. Would be a nice feature

While it is somewhat brute force, it is relatively cheap. get a 120VAC to DC charger like this one and it will DC isolate the input side from the output side. Then you can attach it to the input side (which should go directly to your Chassis alternator/battery) of your DC-DC charger and power it from any AC supply (e.g. shore power or Inverter) and control the charging however you wish but probably not while the engine is running.

https://www.harborfreight.com/4-amp-...ner-63350.html

[motovan_mn]

Originally Posted by posplayr

While it is somewhat brute force, it is relatively cheap. get a 120VAC to DC charger like this one and it will DC isolate the input side from the output side. Then you can attach it to the input side (which should go directly to your Chassis alternator/battery) of your DC-DC charger and power it from any AC supply (e.g. shore power or Invertor) and control the charging however you wish but probably not while the engine is running.

https://www.harborfreight.com/4-amp-...ner-63350.html

I think OP was asking how to keep their starter battery topped off using the existing solar panels on the van.

Could they plug that linked battery charger into their solar system's inverter, and hook up the 12V output to the chassis battery as you described?

Alternatively, they could could buy a dedicated solar panel trickle charger like this:
https://www.amazon.com/Sunway-Solar-...ergysm-20&th=1

[posplayr]

Originally Posted by motovan_mn

I think OP was asking how to keep their starter battery topped off using the existing solar panels on the van.

]

If you run an inverter off the haus battery and you have solar I assume that solar charges the haus battery, and so you have what you want. (more below)

Originally Posted by motovan_mn

Could they plug that linked battery charger into their solar system's inverter, and hook up the 12V output to the chassis battery as you described?

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Yes, it is an isolated output so any ac input. An independent dashboard solar charger for the cigarette lighter would work as well.

The benefit of the ac input (off inverter) is that if you have 300 amp-hrs of LiPO you always have plenty of power to keep your chassis battery up. It will also support 4 amps @12v charging which is much more than any small solar input.

That solar panel lists 4W max solar so that is going to be 4/13=0.3 amps MAX in comparison. In the AC-DC case, the solar panel doesn’t really matter compared to solar battery charger's limits.

[Kibo]

Not sure if it helps any, but my 2011 E350 has the 'EXTRA HVY DUTY 225-AMP ALT' option (from the Monroney) and has had no problem keeping up with my Kisae 50A DC-DC (DMT1250). I do have a new-ish Odyssey 65-PC1750T. I'll have to look the next time I'm charging 50A at idle to see what the battery voltage reads at the Kisae.