Charge controllers

[Scott3569]

well what can I say guys, Sometimes my head is not on to damn tight, been going back and forth about my power situation.. I know I need power.. there i no question in that.. Will it happen immediately NO it will not.. But it does need to happen pretty quick.. 

So I think I have a basic idea of what my power consumption will be and I am thinking 500wh will probably be enough.. at least to start.. 

I know what batteries I will end up with when I actually get there.. and I will start off with 1@ 100AH.. and probably 1 100w Solar panel.. I know the solar panel probably will not be enough, but that combine with a little driving (delivering/working). I think it should be fine.. 

But as the title says, I obviously need a charge controller.. 
I have been set on the Renogy dc-dc 30am Controller the link is below

https://www.walmart.com/ip/Renogy-D...BqMD2S8Hm_qEETlJuaBoCu3MQAvD_BwE&gclsrc=aw.ds

Now, my question is Do I really need to have that?? 
what I mean is If I connect an AGM 100AH to my battery won't a normal Charge controller do the same thing? 

For example:https://www.renogy.com/rover-elite-20a-mppt-solar-charge-controller/

And yes I know I am linking to different controllers here. Renogy does not have the one I was looking at on their site

I also understand it would be a 20A and not a 30A, But I honestly don't believe I would even need the 30A.. 

I hope I have laid all this out correctly and so that you can understand my thought process here.. 

and I serious appreciate all the help everyone has given me.. even though someone of you have probably been scratching your head on a few of my threads 

BTW I am not married to Renogy, if there is another controller out there good customer service reliable product, good price..  please let me know.. 

 

[highdesertranger]

I feel it all depends what you want to end up with.

IMO for small systems with low voltage panels there is no reason to go with a MPPT controller a PWM will work fine. I used a PWM for about 10 years it worked fine. But I had a small system with low demand.

IMO your better off getting the higher voltage/wattage panel and a MPPT controller. However it don't ever plan on going for a bigger system then just stay with the lower voltage and a PWM.

I like Victron or Morningstar for controllers.

Highdesertranger

 

[MGfromBC]

I'm thinking about and asking similar questions myself.  I found this site helpful in learning enough to at least know what questions I wanted answers to.

The Definitive Guide to Solar Charge Controllers: MPPT and PWM Charge Controllers in Off-Grid Solar Power Systems (solarpanelsvenue.com)

MG

 

[jimindenver]

Do you need the first controller? no

I suggest that if you even think of getting more panel I would get at least the Victron smart solar 15 amp MPPT with blue tooth. It has better features, is more easily settable and cycles faster than the Renogy's.

Do you need MPPT?

I agree that a single 100 watt panel doesn't require a expensive MPPT. It already produces so little power that the improvement with MPPT would only be 1.5 amps at peak. Believe it or not that measly 1.5 amps is a good sized portion of what you will see out of a 100 watt panel on PWM.

What does 1.5 amps mean in the long run?

It's measly, right? What consequence could it have in day to day use? Track the sun with that 100 watt panel a full summer day and you are looking at peak out put for 12 hours or better. That's a 18 amp improvement. That's nearly 36% of your usable battery capacity and a little under half of your 500 wh draws. It's not so measly when compared to your capacity and loads.

This is what I see. Your 500 wh loads convert into 41 amp hours. That's really close to the usable capacity of a 100 Ah AGM. You don't have any room for unexpected loads, bad weather days or the like. The 100 watt panel flat mounted certainly will not cover it even with a MPPT controller because at peak it only produces 5.4 amps on a MPPT controller during the 5 hours of peak sun a day. That's less than 30 Ah's and closer to 20 amp hours with a PWM.

That's why I suggested a 15 amp controller because I see a second panel in your future. 200 watts at peak will produce you daily needs even if you did use a PWM. They will produce at least 8 amps x 5 peak hours = 40 amp hours along with the shoulder hours is enough. On MPPT you are looking at over 11 amps which will easily cover your needs and provide a small buffer.

 

[PeterPiper]

I use a Xantrex C40 PWM controller in my minivan with two 100 watt panels.

That thing keeps my batteries charged like no bodies business.  Every battery I keep on that controller for a while gets a good increase in capacity.
I rotate my tired, slouching batteries on it for a while and it revives them.

I think I paid $35 for it.

On a small system a good quality PWM controller works well.

 

[jimindenver]

It isn't how well a product works. It's how well it meets your needs.

 

[Scott3569]

@JiminDenver

My plan is to add a solar panel and another 100AH AGM I would imagine the Victron Charger Controller your talking about will be fine with the future plans of my system..

And yes of course you are correct, I will add another solar panel.. once I get the full system, I really feel like it will be more than enough..

But just in case, how much can that controller handle? what would max it out?

 

[jimindenver]

The 15 amp Victron 75/15 will handle 220 watts. You could run the panels in series to get a little better output, just keep them the same.

The Victron Energy SmartSolar MPPT 75V 15 amp charge controller is $118.

https://amzn.to/2SgVZfU

The blue solar version is only $88 but you have to buy the bluetooth dongle killing any savings.

 

[jonyjoe303]

for a 100 watt panel I wouldnt get more controller then you need. A 20 dollar pwm controller will work as well as the 200 dollar renogy. With a low voltage (21 volt) panel the most amps you see is 5 amps with either pwm or mppt. Mppt requires the high voltage (36 volt) panels or 2 of the lower voltage panels connected in series.
Mppt requires the higher voltage for best performance and converts that extra voltage to more amps.

Myself I would stay away from a controller that doesnt have an LCD screen so you can program. I wouldnt even consider the renogy, no matter how good the reviews are due to it doesnt have an LCD screen. If you have to rely on bluetooth or seperate dongle to program it that is a deal breaker. 

I been using the makeskyblue 60amp (130 dollar) mppt for the past year. Its been excellent. On my 365 watt panel I seen it extract up to 375 watts (27 amps of charge power). Everything is programmable on the LCD screen and I been using it on my 220ah lifepo4, so it easily will work on lead acid. One feature it has that I dont see on other controllers is the ability to calibrate the controllers voltage to the battery terminals voltage. This will compensate for any voltage drop that all controllers have. You can use this controller on a 100 watt panel but it will only give you 5 amps, but its cheaper then the renogy and can handle much larger panels when your ready to upgrade.

makeskyblue 60a mppt controller performance. note the lcd screen, you can cycle through the watts, amps, and program all the settings right on the controller. Its connected to a 365 watt panel, it maxes out at a little over 27 amps of charge power.

 

[hugemoth]

The $15 Chinese charge controllers on eBay work just fine. They have an LCD screen and are adjustable. I've been using one for about 8 years now.

 

[Camper]

Fancy brand names don't impress me any longer at all... I use a $20 MPPT from eBay and it works perfect for me every day.

 

[sneaks]

You’ve had a few well-respected, knowledgeable members give their thoughts. Definitely take that info for consideration, read the links they dropped. I did a ton of research before I dipped my toes into solar. I went cheap, cheap. It for me this was a POC and never planned as a long term installation. I figured for $50 between controller and panel, if I did something stupid as my first attempt, I’m not out any significant $. I’m also not living out of my rig so I have the luxury to experiment. Now that I have some experience and better hands on knowledge, I’ll be improving my system.

What I don’t see many people talk about is the other stuff that isn’t a controller or panel when it comes to factoring costs and being on a budget: wires, fuses, etc. They can add up fast. No matter what you end up as your first panel and controller, don’t skimp on the wires. You want to only run this stuff once through your rig, get good stuff.  Size for future needs. Avoid the crappy audio-quality aluminum core crap. Invest in a good crimper. Invest in good connectors & shrink wrap. Don’t forget to use grommets, strain relief, proper colors, and safe routing. Think about chafe points, protect the wires with a good loom. Do yourself a favor and plan out exactly where things are going to run, add a few extra runs for unexpected add ons, keep it organized. Give yourself a little extra length, there’s always an obstacle or unexpected route change that you need to factor in. Doing all this means that if\when you upgrade, all you have to do is swap controllers and\or panels, everything else is up to snuff.

 

[Scott3569]

You’ve had a few well-respected, knowledgeable members give their thoughts. Definitely take that info for consideration, read the links they dropped. I did a ton of research before I dipped my toes into solar. I went cheap, cheap. It for me this was a POC and never planned as a long term installation. I figured for $50 between controller and panel, if I did something stupid as my first attempt, I’m not out any significant $. I’m also not living out of my rig so I have the luxury to experiment. Now that I have some experience and better hands on knowledge, I’ll be improving my system.

What I don’t see many people talk about is the other stuff that isn’t a controller or panel when it comes to factoring costs and being on a budget: wires, fuses, etc. They can add up fast. No matter what you end up as your first panel and controller, don’t skimp on the wires. You want to only run this stuff once through your rig, get good stuff.  Size for future needs. Avoid the crappy audio-quality aluminum core crap. Invest in a good crimper. Invest in good connectors & shrink wrap. Don’t forget to use grommets, strain relief, proper colors, and safe routing. Think about chafe points, protect the wires with a good loom. Do yourself a favor and plan out exactly where things are going to run, add a few extra runs for unexpected add ons, keep it organized. Give yourself a little extra length, there’s always an obstacle or unexpected route change that you need to factor in. Doing all this means that if\when you upgrade, all you have to do is swap controllers and\or panels, everything else is up to snuff.

Yes I agree with you on the wiring, and I have planned out were everything will be going.  I don't know a lot about electrical things.  But I do know I don't want to undersize my wiring.  And I don't believe I have to this point.. and I will be adding fuses before I go much further.. especially when I get my solar set up

 

[1shemp]

KISS.you could buy another panel for what an mppt costs.

 

[Scott3569]

@ 1shemp
I am sure that is true.. however I will not be staying in this van more than a year or two.. I will get something larger.. so my thought is to try to purchase something that 1 I can expand with when I do get something larger

@jimindenver

So if I get just the controller you mentioned in your previous comment.. will that alone charge my house battery while driving? So that then I will at least have some back up power.. then a little later down the road get the solar panel?

Reason I ask is I will be doing door dash for so I will be driving a quite a bit.. this will only be for about two months then I will have the ability to get the solar panels..

 

[XERTYX]

You know my opinion brother. Buy once cry once.

I gave you a break down of my cost thus far. If it ain't in the budget it ain't in the budget. But I'll say this. The cloudy weather we've been having in GA recently havent phased me. The panels in series get up to a respectable voltage even in low light. In really low light I'm only seeing slight charging BUT with 1 panel I'd be seeing about 9 volts in seriously low light and no charging at all whereas in the real world I'm getting a little trickle.

I didnt mention I dont think that I also bought the ~$30 wifi module for my system so I have real time monitoring. Yesterday I went to check on my system (dark stormy skies) and I was seeing about what I normally would around that time of day even with moderate clouds. It was almost done charging and only putting out about 50 watts.

It took until about 2pm with no sun at all to fully charge. Most full sun days it's done by 1pm. Sometimes a little sooner as where it sits it sees sunlight at about 8am.

I like my EPEVER charge controller. I really like it. Its middle of the road. It wasn't $200, not even $100. It works, does its thing and keeps on truckin.

I've never heard any bad word on victron. Quite the opposite actually. They're a damn good piece of kit. I think epever doesn't get the love it deserves. Also I'd never again wire panels in parallel after "seeing the light" about what series panels and an MPPT controller can do.

My last system with parallel panels and a $10 charge controller had me praying the rain away. Haha. And that one was just a hobby solar system, not life support. My $0.02

 

[Scott3569]

Yes I agree, I don't want to have to buy things twice.. and I certainly have taken your advice.. I looked at those controllers you mentioned in your break down.. and I didn't see where they had much of a customer service here in the USA.. 

Bcause I am such a novice with this, I would like some good customer service.. yes I say that lightly.

 

[XERTYX]

That's understandable. In my experience I haven't needed any customer service level help. It's pretty well plug and play. Except for the 2 button interface. That was a little tricky.

If you can program a VCR I think you can set the CC to FLA like I did. I had mine for a few days before I got the wifi adapter. And it just worked. If using lithium I wouldn't do it with the 2 push buttons. Like not even in the apocalypse.

 

[flying kurbmaster]

@ 1shemp
I am sure that is true.. however I will not be staying in this van more than a year or two.. I will get something larger.. so my thought is to try to purchase something that 1 I can expand with when I do get something larger

@jimindenver

So if I get just the controller you mentioned in your previous comment.. will that alone charge my house battery while driving? So that then I will at least have some back up power.. then a little later down the road get the solar panel?

Reason I ask is I will be doing door dash for so I will be driving a quite a bit.. this will only be for about two months then I will have the ability to get the solar panels..

 

[66788]

I feel it all depends what you want to end up with.

IMO for small systems with low voltage panels there is no reason to go with a MPPT controller a PWM will work fine.  I used a PWM for about 10 years it worked fine.  But I had a small system with low demand.

IMO your better off getting the higher voltage/wattage panel and a MPPT controller.  However it don't ever plan on going for a bigger system then just stay with the lower voltage and a PWM.

I like Victron or Morningstar for controllers.

Highdesertranger

I had a Morningstar TriStar 45 PWM in the stepvan for 3 years and it did its job flawlessly.   The reason I replaced it was incompatibility with my Propex heater.   The Propex faults out right at 15 volts.   It's easily resetable, but constantly faults at 15 volts, which is normal for that heater.

This was not a problem until I moved to Southern Oregon where winter days can top out at 25 degrees or less, and the solar output consistantly was 15.5 volts during the day.   The high voltage set point is not adjustable on the TriStar PWM controllers.    Plenty of great heat at night, but when the sun came up, the heater quit.

The MPPT I replaced it with allows me to set voltage points as needed, so now  the Propex is happy and so is my cat.

If the equipment meets your needs, no problem.   If not, time to rethink the system layout.