wiring fixed and deployed solar to one controller

cruxarche

Observer
Fwiw, My popup trailer I plan to fit a solar controller behind its lower refrigerator grille. Solar controller is nothing what needs regular attention, But still want access to it when roof is down
My controller does not have remote temp sensor so I’m trying to find a way to mount it on the tongue near the battery pack. Not sure how much difference it makes though. Inside would be easier for sure. It was a pain mounting the shunt and fuse box under the trailer.
 

pdavitt

Member
My controller does not have remote temp sensor so I’m trying to find a way to mount it on the tongue near the battery pack. Not sure how much difference it makes though. Inside would be easier for sure. It was a pain mounting the shunt and fuse box under the trailer.
Actually, Victron makes a remote temperature device that is compatible with your SmartSolar, BlueTooth Enabled Charge Controller. It's called "Smart Battery Sense" and the manual can be found here: https://www.victronenergy.com/live/smart_battery_sense_manual
It cost about $40 bucks.

Using the Victron Connect app on your smart phone you can setup a Victron Smart Network so the two devices can talk to each other using a Bluetooth connection. Hard wires, between the Battery Sense device and the Charge Controller, are not needed.

Hope this helps,
Pat
 

cruxarche

Observer
Pat,
Somehow I missed that. $40 is well worth the time and materials it would take me to build and mount a weatherproof enclosure on the tongue near the battery box. And I am already familiar with the bluetooth app from the smart solar controller and the bmv 712 battery monitor.

Thanks for the suggestion. I just picked up a couple of 50w flexible 12v (18vmp) panels to build my own lightweight solar suitcase. Won't be long til I have 100 watts up top and another 100 portable.

Thanks again all posters.

Scott.
 

cruxarche

Observer
if anyone has any suggestions on how to mount/manage the 50w flexibles as a portable solution (solar suitcase or otherwise) please let me know. I am pretty much making it up. Looking primarily for the the following attributes:
1. protect panels during transport
2. protect panels from ground when deployed
3. stand/mount to support panels when deployed.

Thanks!
 

luthj

Adventurer
Two aluminum sheets bound with a slightly offset hinge. Bond the panels to the aluminum. A folding leg would be simple, as would a latch or bungee loop to hold it closed. Rivets to connect the various bits together.
 

cruxarche

Observer
luthj,
I was investigating Aluminium sheet, but don’t have much experience with it. I assumed I needed at least 1/8” and at first glance the price and weight were off off putting . Do you have sense of the minimum thickness that would be effective?

To reduce materials I also considered an aluminum piano hinge of some type with some additional aluminum straps to complete the support. But was not sure of the best design.

The connections are on the front side of the panels. Would I still benefit from an offset hinge?

Thanks!
 

cruxarche

Observer
Thanks luthj,
those alubond sheets are pretty cool. I am not familiar with them. I may also consider doubling up some corrugated polypro sheets and test them out as well.
 

cruxarche

Observer
So I have this prototype ready to go. I used aluminum sheet and offset hinges to avoid binding. I am using two 50w flexible panels. I have I bought the MC4 connectors to set it up wired parallel. I am charging a single 12v battery with a victron MPPT 75/15 because I like the app and have other victron stuff.

Question: The parallel wiring takes up more space and uses more connectors. Could I wire these two panels in series? Or would it be a waste of energy because the controller would have to step down the voltage?
 

Verkstad

Raggarkung
Question: The parallel wiring takes up more space and uses more connectors. Could I wire these two panels in series? Or would it be a waste of energy because the controller would have to step down the voltage?
Using your MPPT controller, Series is better wiring scheme.
Aside from loss inherent with any energy conversions,..
MPPT is not wasting energy ’stepping down’ voltage. MPPT takes all that voltage then magically converts it to the lower target voltage but at higher amperage. Amperage is magic pixie stuff what fills a battery. More amps fills battery faster.

If using PWM controller. Those type just reduce voltage to whatever its target output voltage is supposed to be. It cant convert those extra volts into anything. It just leaves them behind.

Some will say thats not wasted energy, its just potential energy that was not captured...
The mind boggles.
 
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