12V 10W Solar panel with MPPT into a MPPT controller?

[sspark]

Hi gang, I have a question if anyone here can help me with.

I installed a Victron 75WV 15A MPPT solar charge controller in my SUV the other day to connect my 100W foldable solar panel to charge my Odyssey deep cycle AGM car battery that I use as the main starter and for auxiliary to power things like a fridge, and many led lights.

My question is, I purchased a ‘Renogy 12V 10W Solar Charger and Maintainer with built in MPPT Charge Controller’ hoping to keep my battery topped off when parked for a few days (no fridge or any auxiliary things running). This 10 Watt mini panel does have a MPPT charge controller built in. Would it be okay to plug this panel with the MPPT into my Victron MPPT controller? I have the Victron PV input port right in my dash for easy access, and I’d love to plug this 10W mini panel in there if possible. If not, I'd have to run new wires directly to my battery as the 12V port is not hot when car is off.

Thanks in advance.

 

[calicamper]

Hi gang, I have a question if anyone here can help me with.

I installed a Victron 75W 15A MPPT solar charge controller in my SUV the other day to connect my 100W foldable solar panel to charge my Odyssey deep cycle AGM car battery that I use as the main starter and for auxiliary to power things like a fridge, and many led lights.

My question is, I purchased a ‘Renogy 12V 10W Solar Charger and Maintainer with built in MPPT Charge Controller’ hoping to keep my battery topped off when parked for a few days (no fridge or any auxiliary things running). This 10 Watt mini panel does have a MPPT charge controller built in. Would it be okay to plug this panel with the MPPT into my Victron MPPT controller? I have the Victron PV input port right in my dash for easy access, and I’d love to plug this 10W mini panel in there if possible. If not, I'd have to run new wires directly to my battery as the 12V port is not hot when car is off.

Thanks in advance.

A hard panel 10watt easily maintains a 12v battery. I use two of those 10watt panels to power my camping setup?. One panel easily maintains the battery
But two controllers no bueno

 

[wirenut]

I don't see that working. You need to hook the output of a charge controller to the battery, not another controller's input.

 

[Roaddude]

Hi gang, I have a question if anyone here can help me with.

I installed a Victron 75W 15A MPPT solar charge controller in my SUV the other day to connect my 100W foldable solar panel to charge my Odyssey deep cycle AGM car battery that I use as the main starter and for auxiliary to power things like a fridge, and many led lights.

My question is, I purchased a ‘Renogy 12V 10W Solar Charger and Maintainer with built in MPPT Charge Controller’ hoping to keep my battery topped off when parked for a few days (no fridge or any auxiliary things running). This 10 Watt mini panel does have a MPPT charge controller built in. Would it be okay to plug this panel with the MPPT into my Victron MPPT controller? I have the Victron PV input port right in my dash for easy access, and I’d love to plug this 10W mini panel in there if possible. If not, I'd have to run new wires directly to my battery as the 12V port is not hot when car is off.

Thanks in advance.

.
Hey @sspark, I don't know your full setup and if it's possible, but why not leave your 100w foldable hooked up when parked, running through your Victron 75|15 to keep the battery topped off?

I have a 120w folding panel that I used to always put away every time I broke camp and hit the road or was parked. Then started keeping it on top of my trailer's RTT when underway and when parked to keep the trailer's dual AGM Odysseys topped off all the time.

Even laying flat all this last year and never moving, it worked so well I am replicating it for my van; another 120w folding panel with a quick-release mount on the roof to keep a 100ah Odyssey house deep cycle topped off for the fridge, small batt chargers, occasional lights, USB and 12v outlets, and inverter, etc.

That way I can remove either or both units from the roof it's on and place around camp for maximum gain. I've fabbed up several 25' 10 AWG extensions with Andersons so can reach out about a hundred feet. And when underway or parked in a driveway can keep them on the roof topping everything off.

I would not plug your 10w maintainer with it's own charge controller into another charge controller, for the reasons already outlined by others.

If you can't leave your 100w panel going when parked, many on-panel charge controllers can be simply bypassed/eliminated from the wiring run by adding an Anderson plug at the panel and an extension with an Anderson on one end and the appropriate SAE or whatever to go into the charge controller.

edit: Some folks have great luck with Victron support with questions like this; others not so much. It may be worth a shot to reach out to them and see what they suggest in your situation. Be aware, though, that right now most outdoor and recreational vendors are experiencing historic surges in interest and sales, so may not be as typically responsive as we'd like.

AND, if your 12V port is not hot when the car is off but that's where you want to plug in the 10w maintainer, it's not going to charge anyway, right?
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[calicamper]

I only have a hard 10watt panel. I have a hard time thinking they are adding controllers to cheap 10watt panels. I literally just have a Renogy 10watt it was like $30. Mine are aluminum framed hard panels almost 9 yrs old left out all yr they work great zero issues. My controller is a generic $20 controller. My last battery lasted 7 yrs.

 

[Roaddude]

I only have a hard 10watt panel. I have a hard time thinking they are adding controllers to cheap 10watt panels. I literally just have a Renogy 10watt it was like $30. Mine are aluminum framed hard panels almost 9 yrs old left out all yr they work great zero issues. My controller is a generic $20 controller. My last battery lasted 7 yrs.

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I find it odd, too, that vendors may be adding MPPT charge controllers to lower wattage panels, though perhaps things have changed in the electronics of it all. For a long time, PWM charge controllers were just fine for small installs like we use on vehicles and adventure rigs, and MPPT (maybe because of cost?) were used primarily for higher wattage installations; I mean a lot higher, like for housing.

I've had a Zamp Solar 15AW PWM charge controller for my 120w folding panel in my trailer set up for years and regularly pull in the max for my dual Odysseys (100ah together), and have never felt lacking. I think a lot of it is marketing and that folks read MPPT controllers handle higher voltage better, so assume it must be better for all applications and spend the extra moohlah. When the truth is for simpler/smaller 12v applications, PWM is often just fine.

That said, I do like the Victron MPPT and bluetooth capability to control and view what their MPPT controllers are doing. I have one of each; a Victron MPPT and a ZAMP PWM, and will be running them separately with identical folding panels, both going into 100ah of Odyssey deep cycles in isolated systems (not connected to starting batts) and will be interested to compare what's coming in and going to the batts in the same location and environment.
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[john61ct]

Victron 75W 15A MPPT solar charge controller

75/15 means 75 **voltage** maximum, really 65V max Voc would be safer.

In order to turn on, it must detect a panel output voltage ~5V higher than your selected CV setpoint

for Odyssey 14.5V iirc?

So likely best to bypass the Renogy SC and wire that little panel direct to the Victron.

Note the SC should be right near the target bank, and any intermediate connections (varying resistance) between the SC and panels may interfere with the accuracy of the MPPT algorithms - irrelevant at only 10W though.

I sure hope not using a ciggie style port there!

 

[LilKJ]

Remove the 10W controller from the circuit and simply wire that panel into your victron.

 

[sspark]

Thank you all for your time and input, it was greatly appreciated.
Based on your suggestions, I've decided to run the 10V panel directly to my battery to avoid any issues by connecting the mppt output to another mppt input. I wish I had the option to disconnect the Renogy SCC, but upon opening the back cover, no wires were accessible as they covered everything with some sort of sealant. I also wish I could use my foldable 100W instead, but I highly doubt it will still be on my car the next day.
Thanks again, and happy wheeling!

 

[calicamper]

Thank you all for your time and input, it was greatly appreciated.
Based on your suggestions, I've decided to run the 10V panel directly to my battery to avoid any issues by connecting the mppt output to another mppt input. I wish I had the option to disconnect the Renogy SCC, but upon opening the back cover, no wires were accessible as they covered everything with some sort of sealant. I also wish I could use my foldable 100W instead, but I highly doubt it will still be on my car the next day.
Thanks again, and happy wheeling!

Are you sure your 10watt has a controller? I have major doubts it would. If it doesn’t it will cook your battery to a crisp. This is what my 10watt looks like. No controller just a diode and wires in the box. A MPPT controller will be a larger box and typically have a screen and buttons to select charge profiles.