Solar panel connection

[Tauras Junior Member Find all posts View Profile Close Tauras]

I currently have a 12v fridge running through a 6 B&S cable from aux battery to the rear, that wire is dedicated to the fridge only and I have another wire for everything else. I would like to incorporate a 120w solar panel and would like to connect it to the same wire as the fridge, I would do that by getting an anderson plug splitter.

Does anyone see any issue with that? I'm trying to get my head around whether the wire can simultaneously draw current from battery to fridge while putting current into battery from the solar panel?

[AussieAndy Find all posts View Profile Close AussieAndy]

No problems doing that at all, should be fine

[oceanracer Moderated member Find all posts View Profile Close oceanracer]

I have the primus portable power pack and feed solar power into it while the fridge is plugged into it no probs, Anderson plug feeding inton the batt and12v socket for the fridge

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

No issue, the solar panel when charging will supply the fridge, the excess current it generates
will go to the battery, it would be better if the panel was connected directly to the battery
but what you propose will still work ok.

[Tauras Junior Member Find all posts View Profile Close Tauras]

So I have tested this setup over the weekend, when the battery is at 11.5v the regulator returns approximately 12.5v at say 4A. I know that the panel is generating over 19v, so shouldn't the regulator be generating around 13.8v given the battery is low? 12.5v does not seem high enough to recharge the battery. This setup did not seem to produce a difference when the compressor was on or off. I did not test it connected direct to the battery, and my next step will be to test at the terminals to determine if there is a voltage drop somewhere, although I doubt this. Any ideas?

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Hi Tauras, when using solar power, taking volt and current reading, unless you know what you are doing, are just confusing.

To get a truly accurate idea of what is going on in your system, you need to be using watts as the reference for both the output of your solar panel and the supply to your battery.

Putting this in a simplified way, the way your solar reg works is that it takes the higher voltage, but lower current coming from your solar panel and converts it to a lower, safer voltage but at a slightly higher current.

Now because the current output of your solar panel is not that high in the first place, the output voltage and current going to your battery is not going to be that high, while the battery is in a low state of charge.

But if you leave the battery connected to the solar reg long enough and without any loads running off your battery, your battery will eventually reach a fully charged state, at which time, the solar reg will have an output voltage in the low to mid 14v, and the current level will be quite low.