Renogy DCC50S firstimer

[ARDUB]

I'm hoping to find someone who has installed this DC to DC charger/MPPT solar controller. I tried calling Renogy. That didn't work so I set up a "ticket" to ask a tech a couple of questions. In spite of them saying that they usually reply within 24 hours, four days later I had a rather vague response. The question had to do with ANL fuse sizes Renogy quoted that did not exist. I was told I could use larger fuses. Hmmm. I then noticed that the Power and Current figures given by Renogy didn't seem (to me) to add up. A little knowledge can be a dangerous thing, and I may have something FUNDAMENTALLY wrong. What follows is the question I sent them 8 days ago (and still haven't gotten an answer.) :

These are two statements made on the DCC50S SPECIFICATIONS page:

Maximum Charging Current : 50A (25A Alternator / 25A PV) Maximum Alternator Input Power : 660W

There seems to be a contradiction. I believe only one of them is correct. Maximum Alternator Charging Current is 25A AND
Maximum Alternator Input Power is 660W ???
Power=Current X Voltage (W=A x V)
If the first statement is correct, then the Maximum Alternator Power is 300W not 660W. W= 25A x12V W=300W
I the second statement is correct, then the Maximum Charging Current is 55A not 25A. 660W=A x 12V A = 55A

SO, WHAT IS THE MAXIMUM CHARGING CURRENT AND MAXIMUM ALTERNATOR INPUT POWER OF THE DCC50S ?

Essentially, how can the "Maximum Charging Current" of the Alternator be 25A if the "Maximum Alternator Input Power is 660W ?

Am I missing something? Ardub

 

[DIYVan]

Watch Will's test video, he goes through the scenarios. It's 50A from the alternator until there's voltage at the PV input and then it drops to 25.

 

[tictag]

It does seem quite misleading but do remember that these are 'maximum' values, under normal operation, these maximums may not be reached. For example, if the unit is charging your battery from the alternator at 25A then it will only be drawing between 263W - 365W (10.5V - 14.6V) from the alternator and, as it says 25A maximum charging it will never draw more than this, meaning that Maximum Alternator Power Input is a bit of pointless parameter.

Does the DCC50S support 24V battery systems? If so, 25A at 33.2V is 830W, which obviously breaches this maximum.

I would just ignore this Maximum Alternator Input Power parameter because, for a 12V battery system, this limit would never be reached.

 

[boondox]

The DCC50S doesn't support 24V systems. It will indeed pull 50 amps from the alternator as I have watched it do so. I don't have solar on the van yet, the panels are on order and I am working on the rack. I will have an easily accessed breaker for the solar as I can see situations where you are getting some nominal amount of solar coming in and it prevents pulling the max from the alternator.

 

[Andreas]

The DCC50S doesn't support 24V systems. It will indeed pull 50 amps from the alternator as I have watched it do so. I don't have solar on the van yet, the panels are on order and I am working on the rack. I will have an easily accessed breaker for the solar as I can see situations where you are getting some nominal amount of solar coming in and it prevents pulling the max from the alternator.

Maybe you can help me. The voltage limit from the solar panels into the DCC50S is 25v. Seems like most solar panels each generate more that 12v so it I want more than 1 panel, I cannot connect them in series. Is that correct?

What do you, or anyone reading this, suggest for a 400Watt solar panel, I'm thinking 2 x 200Watt panels. Do I connect in series or parallel? I dont know much about solar panels but it seems that most will exceed the25v limit when connected in series.

I want to replace my Sterling 1260 with the renogy dcc50s giving me the ability to add solar at some later point, but soon.

 

[boondox]

No, you don't want to put them in series. Look at the VOC of any panel you want to use. 2 x 200 watt panels in parallel will be fine, as long as the are 12V type panels.

 

[Dzl]

You might want to checkout this thread https://diysolarforum.com/threads/renogy-dc-dc-charger-w-mppt.1406/

 

[Dzl]

Maybe you can help me. The voltage limit from the solar panels into the DCC50S is 25v. Seems like most solar panels each generate more that 12v so it I want more than 1 panel, I cannot connect them in series. Is that correct?

Correct, you are limited to connecting panels in parallel and limited to using '12v' panels (which usually have a Voc of around 21-22 volts I believe)

What do you, or anyone reading this, suggest for a 400Watt solar panel, I'm thinking 2 x 200Watt panels. Do I connect in series or parallel? I dont know much about solar panels but it seems that most will exceed the25v limit when connected in series.

I want to replace my Sterling 1260 with the renogy dcc50s giving me the ability to add solar at some later point, but soon.

What is the Sterling 1260? Based on what I've heard, Sterling Power has a better reputation as a company than Renogy. If your only goal is to add Solar down the road, just buying a MPPT charge controller is a better option probably if the Sterling meets your alternator charging needs.

As for recommendations on panels, just pay attention to the Voc of the panels, the total array should be below 25V with some cushion. Most 100W panels should fit the bill, but there are probably 175-200W panels that fit the bill as well.

 

[ARDUB]

Will Prowse in his review of the DCC50S addresses the 25V limit at about 4:20 into the video.

It doesn't seem to me to have a big downside except at lower voltage having to run larger wire. I haven't worked out the details yet and it's great to hear some of the same questions I would be asking.

WHY HAVE A DC TO DC CHARGER?
I would like to throw this out there. I purchased 2 Battleborn 10012 LiFePO4 batteries. I now have them installed along with the DCC50S in a class C motorhome. Battleborn presents these batteries as "drop in replacements". BUT as soon as I started talking to BB's tech department, it was brought up that charging batteries directly off the alternator (start batt +) using the OEM relay/isolator was "fine for lead/acid batteries, but could/would present problems for the lithium batteries and the alternator if the alternator's output was greater than 100A." My 2003 Ford E450 is (I believe) 115A. As I understood from Battleborn, alternators alone do not present a good charging profile for LiFePO4 batteries which in the long run could damage them, and the very low impedance of the lithium batteries could damage the alternator. For this reason Battleborn recommended a DC to DC charger. I don't believe I have heard this from anyone other than Battleborn. (please comment)

In the case of most companies, Victron for example, you would need to purchase a separate DC to DC charger AND Solar Controller. To do this with Victron equipment it would cost around $600. That made the DCC50S, which is both a DC to DC charger and a MPPT solar controller, look pretty good at $300.

Boondox, Great idea of being able to easily turn off the solar when it is minimal (and is preventing the batteries from being charged by the alternator.)

 

[Dzl]

For this reason Battleborn recommended a DC to DC charger. I don't believe I have heard this from anyone other than Battleborn. (please comment)

Yeah, I'm not sure if other battery manufacturers acknowledge this explicitly or not, but its the accepted wisdom around here. More so to protect the alternator than to protect the batteries, but I suppose its a bit of both. Victron, Sterling Power, RedArc, Renogy and CTEK all make products to fill this gap. Renogy and CTEK both make duel purpose solar charge controller / battery to battery (alternator) chargers. Both are limited to smaller systems, but they seem like nifty little devices if they meet your needs, and I hope to see more companies coming out with similar offerings.

 

[Andreas]

Correct, you are limited to connecting panels in parallel and limited to using '12v' panels (which usually have a Voc of around 21-22 volts I believe)



What is the Sterling 1260? Based on what I've heard, Sterling Power has a better reputation as a company than Renogy. If your only goal is to add Solar down the road, just buying a MPPT charge controller is a better option probably if the Sterling meets your alternator charging needs.

As for recommendations on panels, just pay attention to the Voc of the panels, the total array should be below 25V with some cushion. Most 100W panels should fit the bill, but there are probably 175-200W panels that fit the bill as well.

Thank you.

 

[Andreas]

Correct, you are limited to connecting panels in parallel and limited to using '12v' panels (which usually have a Voc of around 21-22 volts I believe)



What is the Sterling 1260? Based on what I've heard, Sterling Power has a better reputation as a company than Renogy. If your only goal is to add Solar down the road, just buying a MPPT charge controller is a better option probably if the Sterling meets your alternator charging needs.

As for recommendations on panels, just pay attention to the Voc of the panels, the total array should be below 25V with some cushion. Most 100W panels should fit the bill, but there are probably 175-200W panels that fit the bill as well.

The sterling 1260 is programmable but its loud and for some reason my starter battery has gotten discharged and adding the Sterling 1260 is the only new part of the system. So I bought the Renogy, just waiting for it to arrive. I'll report back after I get it set up.

 

[FastFreddy]

Anybody find 65Amp and 75Amp fuses? I can't find online or locally....

 

[boondox]

I used a 70 and an 80. A little higher than the manual recommends but it will be fine.

 

[tictag]

Anybody find 65Amp and 75Amp fuses? I can't find online or locally....

If you can't find them here, they probably aren't manufactured.

 

[ARDUB]

I could not find either a 75A or a 65A (ANL type) fuse. I called one manufacturer and was told that those amperage fuses WERE NOT MADE. I was able to use a 75A MRBF type fuse on my starter battery positive. (ALT +) These fit a "Terminal Fuse Block" part # 5191 made by Blue Sea Systems or an identical Bay Marine Supply fuse block. This fuse block mounts on the starter positive battery post so if this is under a hood of an RV application, MAKE CERTAIN THAT YOU HAVE HOOD CLEARANCE!! Fuses are sold separately.

In place of the second non-existent 65A ANL type fuse that Renogy wants on the OUT + (charge line to house battery bank), I decided to put a 60A Type 3 switchable breaker. So far it is doing fine.
All of these are available on Amazon. Search these asin numbers on Amazon.

FUSE TERMINAL BLOCK: B075ZJ3MRV
FUSES: B0761JJTYP
CIRCUIT BREAKER: B07DJTLZH9

 

[boondox]

I would have gone one up instead of one down but it should work fine. The breakers are there to protect the wire, not the charger. In my case I used 4AWG so going up 5 amps was fine. One thing is I always recommend buying quality breakers when dealing with high amps.

 

[tictag]

One thing is I always recommend buying quality breakers when dealing with high amps.

Totally agree - lots of horror stories on here about cheap breakers melting, even when used within specs. Personal opinion: littlefuse for fuses, bussman for breakers.

 

[markbrouwer]

Hi guys, hope you can help here. I am trying to contact Renogy but so far no reply.
I am building the same set up (more or less) in my van as Will did in his video above. So far I did not install the PV as they didn't arrive yet, but when testing the dc to dc from the alternator my fuse is jumping (engaging -sorry not sure how to say it in English).
All works fine, leisure battery is charging up to 50.1-50 amps (the bms is working fine, not overcharge), cables not getting hot.
BUT after a few minutes (not many, maybe 4) the 80 amp fuse is jumping and stopping the system.
If I try without the breaker the dc to dc keeps charging and delivering those 50 amps to the battery but getting really hot underneath (I tried without the breaker the first time when checking if system was working) at that point cables were all OK nothing hot.
My set up is
fiat ducato with 12v 95 ah battery
cables all 4 awg (1 meter long from car to charger and 50 cm from charger to battery)
breaker to the dc to dc of 80 amp
so far no breaker to the leisure battery
leisure battery made following Will manuals (12v 190 ah) with a 4S 120 amp bms
Renogy 50A dc to dc

Any idea what could be? Or what I should test?
Thanks a lot for your help.
Mark

 

[boondox]

First thing I would like to do is verify that the input amps are in the 60 amp or so range. I would double check all connection points, lugs crimps, etc. I haven't checked how hot my unit gets while charging, I should have and will do in the future. However, I can't at this point say what is "normal" in terms of heat. It is possible that the breaker is faulty but I think verifying input current is important.