Charging from Alternator via Renogy's DC to DC Charger

[DanDweller]

Does anyone here have actual experience using the 20 amp version of the device mentioned in this video on a smaller van (eg, Ford Transit Connect) or a similar device by another brand?



Unfortunately, the reviewer does not mention whether this device would be compatiblw with the solar charging system I plan on using with an MPPT controller.  I have talked to Renogy's "technicians" and only received conflicting and hesitant answers.  I am trying to get a definitive answer on whether the additional 20 amps draw would be too much for my alternator to handle and whether this will work in tandem with a solar system.

 

[Cajunwolf]

@DanDweller

I don't see why it wouldn't work myself. DIY has a forum, I'm a member there too, there are people over there who are really up on this stuff as power systems are there main focus. You might try contacting Will directly, I have before about my sailboat charging system, and he is accommodating. If you're in doubt about your alternator, check with Ford, or an alternator repair tech. I had to add a bigger alternator on vehicles before to handle additional loads; it's not a problem money can't solve.

 

[highdesertranger]

I would like to point out that anything Renogy sells on Amazon has terrible reviews this DC to DC charger is no exception.

when my inverter went out and I was shopping for a new one I liked all the features of the Renogy. however when I read the reviews I said no way.

take Will with a grain of salt. he is in this to make money not help people. if you notice in the video there is a disclaimer that says paid promotion. just saying.

highdesertranger

 

[Cajunwolf]

remove please, an error.

 

[tx2sturgis]

I agree with HDR...both of us (and a few others here) have had to clean up the mess of misunderstandings that Will leaves in his wake. 

Too little info, too much info-tainment.

And I seriously doubt that he would have the ability to predict whether a Ford Transit Connect alternator will overheat or fail if loaded down with an extra 20 amps.

As to whether the B2B chargers will work OK if hooked to the same battery as a typical solar controller, yes, they will work fine, if all the parameters on all devices are set properly.

 

[MrAlvinDude]

hmmm... why not ask Will himself this very question.  If it possible to use either of these DC-DC converters in combination with a mppt solar charge controller? 
Or better yet, with a specific mppt charge controller.

It might even be possible to persuade him to do a video about it.

I do not personally know Will, but from his style of very blunt, straight forward and sometimes very harsh comments of some of the devices that he does test, I am inclined to think that he values his freedom and right to speak his mind, and will not limit or censor negative comments in his videos.
But that is just my personal impression.



Either way, I think, that if the internal design of both chargers use an output diode, then it would for sure be possible to combine two charge systems.  I do however not know any details about the internal designs of  these systems. All I know is that the reference DC-DC boost design  does rely on (and need) an output diode.

 

[Cajunwolf]

@MrAlvinDude

I do not personally know Will, but from his style of very blunt, straight forward and sometimes very harsh comments of some of the devices that he does test, I am inclined to think that he values his freedom and right to speak his mind, and will not limit or censor negative comments in his videos.

This is true, and for that reason, he strikes some folks the wrong way. I have spoken to Will over a year ago. We don't see eye to eye on many things, but he was willing to help me with a question on my sailboat at the time and went out of his way doing research too. My point is this, there are folks on his DIY forums who can help with this and other questions, and I can't see not suggesting a useful resource over personality conflicts. Let others decide for themselves. There are two guys on his forum, for example, that rub me the wrong way and I them, but we've put that aside when trying to help others. That's all I'm trying to say here. If not fond of someone for whatever reason, unless they're doing harm, I don't put them down. How does that old saying go: Let he who is without sin cast the first stone.

 

[MrAlvinDude]

And I seriously doubt that he would have the ability to predict whether a Ford Transit Connect alternator will overheat or fail if loaded down with an extra 20 amps.

Most likely no one can say for sure, not even Ford, as loads vary during a drive.  And it also depends on which electric functions one uses during a drive. 
But focusing on the typical big loads, one might be able to give some advice of what to do and what not to do, in order to limit the likelyhod of overloading the standard alternator.

And I suppose this is why a voltage sensor for the starter battery is requested to be a part of the DC-DC converter used to charge the 'house/aux' battery. As once the starter battery is charged to a high degree, then the amp load from that process will become very much lower, and would leave amp capacity to be available to be used to charge the house battery.

Besides charging the starter battery, the big user decided amp loads, in the cars I have owned, would be the fan that moves air for the ventilation/ac and the 'back window/outside mirror' defrosters.



So perhaps the best advice is; to use a DC-DC converter that has a built in max amp limit (and a 15-20 amp limit sounds quite safe to me) AND that will only charge  the house battery, once the starter battery has been charged enough.

 

[Cajunwolf]

@MrAlvinDude

Dang dude, that's pure common sense, kudos! :thumbsup:

 

[tx2sturgis]

Most likely no one can say for sure, not even Ford, as loads vary during a drive. 

And that was exactly my point.

 

[MrAlvinDude]

I agree with HDR...both of us (and a few others here) have had to clean up the mess of misunderstandings that Will leaves in his wake. 
Too little info, too much info-tainment.

Good to know, but sad to know, as I am one of the people who like the depth and technical details that I frequently see presented in his videos.

But I accept that running an experiment and getting good or interesting data, or setting up a solution that works well for a person with some technical insights,  does not necessarily translate to also be a good installation or setup, for a technical/electrical  novice.

 

[tx2sturgis]

Let me clarify a bit more:

Lots of information presented by youtubers can be wrong, out dated, erroneous, misleading, etc. There is no 'vetting' of the information for the most part. They have no fact-checkers on staff. And, they do not get paid for presenting truth anyway. They get paid for presenting titles and content that is 'ad-friendly' and that people will click on. 

Content is EASY...but 100% correct, provable, well-researched, hard technical content is hard. 

The everyday youtuber presents opinions, not necessarily facts. You have no way of knowing what level of fact-checking, research, experience, or knowledge they have beyond opening a box and hooking up some wires to a new toy. 

I'm not saying Will gets it wrong while everyone else gets it right, what I'm saying is that the content is presented in a pleasant way, so people think that by golly, he MUST have this all figured out. And there is a mix of good and not-so-good information. Or, things that get left out so we end up explaining the details to the newbies that come on board here. 

And its a never ending, thankless job. 

Just make sure to be skeptical when the presenter is being paid to promote him or her self, or endorses a product for money.

 

[highdesertranger]

well said Texas.

I would also like to point out that the video that was posted for the Renogy DC to DC charger was a sponsored video. so in other words he was getting paid by Renogy. all your parents should have warned you about slick talking salespersons. just look at the reviews on Amazon they are pretty abysmal for that device and none of that was mentioned in the video.

I have seen Will give some real good info I have also seen him give some real bad info.

highdesertranger

 

[DanDweller]

I would like to point out that anything Renogy sells on Amazon has terrible reviews this DC to DC charger is no exception.

when my inverter went out and I was shopping for a new one I liked all the features of the Renogy.  however when I read the reviews I said no way.

take Will with a grain of salt.  he is in this to make money not help people.  if you notice in the video there is a disclaimer that says paid promotion.  just saying.

highdesertranger

 In fact those terrible reviews are part of the reason I'm here asking around.  So now that leaves me wondering if I should also forego the solar panels and MPPT controller by Renogy and look for another brand?

 

[DanDweller]

I wish I didn't feel like I was trying to reinvent the wheel here for a very basic system that surely many vandwellers have.  I mean, my main consumer is a 5 amp vent-fan.  Why does it seem so difficult to figure out which components I should get?  I don't have a schematic or diagram to show anyone because that's exactly why I'm here--to figure out what I need. Should I just skip trying to use the alternator and trust that between solar panels and shore power I will be fine?  I just dont want to find myself struggling somehwere, while traveling, to get some ventilation because, even though hot and muggy, the sun is not shining and I don't know anyone else around me to bother with asking to plug into their wall outlet.  My last van, an overoutfitted, gas-guzzling Roadtrel, I drove to Brazil and back.  I might not take my Transit Connect that far, but I might drive it as far as Costa Rica.  I know--crazy.  My panels could get stolen for example.  And it could happen in a town where I don't happen to know anyone.  Then I find myself wishing I could deliver something from the alternator to the Battle Born but don't have a way because no connection was made back during the furstrating days (today) of trying to understand just enough to outfit the van.

 

[regis101]

Don't rule out Renogy. Everything is made overseas for everyone anyways.

I'm using their Rover 20a with a couple 100w mono panels.
Plus I grabbed one of their Wanderer 10a PWM's with a couple 30w mono's for a sub system.
I'm also using a BT-1 module. It tells me what I need to now. It, they, have a small software issue but no big deal.
However, Renogy tech support sux.

 

[Cajunwolf]

In fact those terrible reviews are part of the reason I'm here asking around. So now that leaves me wondering if I should also forego the solar panels and MPPT controller by Renogy and look for another brand?

NO! Why because you're getting conflicting views? I'd say you're on the right track by doing your research like you are because that's what you're supposed to do. Now, I think the Renogy product that a member of a particular person's website and forum I suggested would work fine in your situation, but I can't guarantee it because I don't have all of the data you as it's your project. Go there and ask him on that thread would be what I would do. He seems like the one most able to help you. I can't recommend using that product, not because its a bad product, quite the contrary, but at least I'm being honest with you by telling you I don't know, but here's someone who most likely does. All anybody here has done so far is confuse you, and I, for one, apologize if I have. Now, and once again, if you're concerned about the alternator, take the vehicle to a reputable alternator shop, these guys will know, it's their job. I've taken my work trucks to such people before, and for a reasonable fee, they built my alternator up to handle the load of an inverter run light duty welding machine I carried around with me and suggested the best way to hook things up. That's why I again provided some links for you to explore so you would be fully aware of the ins and outs of using the vehicles alternator for the intended purpose. I was trying to help. Stick to your research Dan, your the one who has to make the decision.

 

[Cajunwolf]

@regis101

Thank you, that was a pleasant breeze of common sense.  :thumbsup:

 

[tx2sturgis]

Should I just skip trying to use the alternator and trust that between solar panels and shore power I will be fine?  I just dont want to find myself struggling somehwere, while traveling, to get some ventilation because, even though hot and muggy, the sun is not shining and I don't know anyone else around me to bother with asking to plug into their wall outlet. 

Do you already have the lithium battery?

If not, just buy a lead acid AGM to power the fan.... and charging it with your existing infrastructure becomes much easier. A super simple and cheap solenoid or switch will keep that house battery happy, it will allow you to charge it with the engine alternator, no worries, and a ventilation fan plus an LED or two is NOT a heavy drain on any reasonably sized lead acid battery.

 

[Cajunwolf]

@tx2sturgis

Dang! Now that's the best advice to date!  :thumbsup: