Mount Solar Charge Controller near Battery or near Accessories? (1 Viewer)

[SnoViking]

Hey Folks,

So I'm in the process of redoing some electrical accessories and am looking for some input. I currently have a Victron solar charge controller and I once had it mounted under the hood, then I had it mounted in the cargo area, and currently it's just laying on the floor in the cargo area. It's bounced around and I have yet to figure out a good place to mount it. It would be nice to have it up under the hood which is closer to the battery and the accessory fuse block but I've heard that the heat under the hood is not the best for it. I tried mounting it in the cargo area driver's side but then I'm running extra wires back and fourth from the battery to the cargo area.

What has everyone else been doing?

 

[CharlieS]

I have a Redarc bcdc in the engine bay with solar input.

 

[spressomon]

Victron states 40C/104F is the max ambient temperature for full output of their MPPT controllers. It can tolerate 60C/140F but presumably will result in diminished output/performance.

https://www.victronenergy.com/upload/documents/Datasheet-SmartSolar-charge-controller-MPPT-100-30-&-100-50-EN.pdf

 

[TeCKis300]

Ideally, it would be close to the battery. Heat concerns may be legitimate. Perhaps a compromise located under the footwell?

Generally close to the battery because any charger relies on voltage feedback to execute optimal charge profiles. Longer wire runs will have minor voltage offsets. Could compensate with larger gauge wire runs. How much this really matters is arguable and heat may be the higher order constraint.

 

[RET2]

Heat, while an issue may not be as big of an issue as one would imagine as a lot of solar is used while stationary and motor isn't running?

 

[SnoViking]

Heat, while an issue may not be as big of an issue as on would imagine as a lot of solar is used while stationary and motor isn't running?

Thats a very valid observation.... .... .... ......

 

[Sandroad]

What about location of the solar panels? That dictate where the CC goes? The CC connected to the starting battery? Is it used just to top off the battery, or for significant solar power input the vehicle?

 

[sdnative]

The SCC needs to accurately sense the voltage at the battery so as close to the battery as possible. Location of the panels is mostly irrelevant as long as the voltage drop is not excessive. Better to have the voltage drop between the panel and controller vs between the controller and battery. For long runs between the panel and controller, a series connection may be better if the controller can handle the higher input voltage.

 

[tincan45]

For those of you who run MPPT charge controllers be sure to run at least two 12V panels in series (24V). Any good MPPT charge controller (especially victron) will not start charging until you are +5V over your battery voltage. This can result a short charge window when you panels are flat on your roof. Sometimes you are better off with a simple matched PWM controller. Just my $.02

 

[FrazzledHunter]

I'm scheduled to get a Redarc BCDC1225D installed and the unit will be mounted passenger-side on the SLEE tray just to the left of the 2nd battery. Location for the connector for solar input is TBD but will likely be mounted to the battery tray.
Out in front heat is supposedly not an issue.

 

[CharlieS]

I think you'll be fine. A lot of people have the Redarc bcdc under the hood. There's lots of real world evidence that it will be fine. Poke around some of the tacoma boards or the Australian hilux/land cruiser boards.

 

[Fisher23]

For those of you who run MPPT charge controllers be sure to run at least two 12V panels in series (24V). Any good MPPT charge controller (especially victron) will not start charging until you are +5V over your battery voltage. This can result a short charge window when you panels are flat on your roof. Sometimes you are better off with a simple matched PWM controller. Just my $.02

I would disagree with that .. just so others know it's not actually true in general. This Maybe true Just for victron?

I have a single 100 watt panel and an MPPT and it runs just fine.

I did buy two 100 watt panels and hand been debating if I want the panels in parallel or series, and was testing the single panel this month. So it's what I have experienced with the Renology panels and MPPT 30 amp controller.

 

[tincan45]

I would disagree with that .. just so others know it's not actually true in general. This Maybe true Just for victron?

I have a single 100 watt panel and an MPPT and it runs just fine.

I did buy two 100 watt panels and hand been debating if I want the panels in parallel or series, and was testing the single panel this month. So it's what I have experienced with the Renology panels and MPPT 30 amp controller.

What do you disagree with? I'm not saying it won't work, you will just have a shorter charge window because the voltage drop will be enough during the early morning hours and evenings to prevent an MPPT charger from charging effectively. A matched PWM would be better suited for a single 12V panel. MPPT in this scenario is just extra money for less performance. I would encourage you to test your system with a PWM and compare. You might be surprised.

 

[Fisher23]

This piece is what I was referring to, " will not start charging until you are +5V over your battery voltage ".

Like I said works find on mine but maybe it is just a victron thing?

 

[rlynch356]

chargers should be mounted as close to the battery as possible but under hood is not a great option since heat will diminish the capacity to charge and shorten life of the charger (good ones are thermally regulated so they decrease current when overheating) an engine bay is pretty hot.

 

[tincan45]

This piece is what I was referring to, " will not start charging until you are +5V over your battery voltage ".

Like I said works find on mine but maybe it is just a victron thing?

It "is" somewhat of a Victron thing since some of the other MPPT chargers will operate at lower voltages, but that doesn't change the fundamentals. Here's a video explaining why in more detail. I only mentioned this because I see a number of solar installs in overlanding designed with single 12V panels or multiple in parallel and they also have expensive mppt charge controllers.

 

[Fisher23]

Thanks for that, I had a posted the that question over in the "power" forum on which was better parallel or series.