Reliable Budget MPPT controller req'd

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Originally Posted by Don 130

Greeting all, I got a 40watt solar charger from Ebay a few months ago to keep a breakaway battery charged up. The controller has failed so I want a recommendation for a reliable budget MPPT controller to run the panel through. I got Victron one for my camper trailer battery but the budget doesn't stretch that far for the cheapie little panel. There are quite a few MPPT controllers advertised on Ebay etc, but I'm after a recommendation based on experience. Thanks.
Don.

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If the controller is mounted on the panel it could be that heat has caused its failure. It’s much better if any controller is mounted away from heat, particularly well away from the solar panel. I use a Victron for the flexible panel I use for topping up the car batteries.

Have you considered hard wiring the breakaway battery to the camper power supply? Doing so would require a fair bit of research as apparently can be quite complex (and well beyond my understanding).

cheers

David

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Originally Posted by DiscoMick

Did you miss the bit where I said to use a controller?
My example was only to show a 40 watt panel was unlikely to overload a 15A controller.

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Your singular post at the time stated “I dont think it would be a problem without a controller at all.” Nothing about overloading a controller.

Remember people don’t always read further on, and it was only later you posted “use a controller”

Keep that in mind.

Wow.......
So much uninformed content.........
I’d suggest people just google the differences between pwm and mmpt.....
You need to understand panel voltage and the benefits of an mmpt...
If you buy the cheapest possible equipment you will see failures......
Nothing wrong with that, just don’t expect different.
Jaycar are usually 12 months behind eBay IMHO.....
Classic Tombie👍
I love the velvet sledgehammer 😂😂😂😂

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Originally Posted by modman

Wow.......
So much uninformed content.........
I’d suggest people I’d suggest people just google the differences between pwm and mmpt.....

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Or perhaps MPPT. :)

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Originally Posted by Tombie

Your singular post at the time stated “I dont think it would be a problem without a controller at all.” Nothing about overloading a controller.

Remember people don’t always read further on, and it was only later you posted “use a controller”

Keep that in mind.

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I was talking about the size of the panel and controller, not about if a permanent controller was needed.

My knowledge of how this things work is clearly lacking. On the suggestion of Gav 110, I connected the panel/controller to a battery and found that the output reading of the controller shot up to 13-15volts. So the controller is not stuffed, but that means I've got a different problem. I tapped into the wiring coming from the towing vehicle to input the power from the solar panel/controller. There is a circuit board in the breakaway battery housing through which the input power flows, so perhaps that circuit is stopping the feed from the panel. My knowledge of these things is well depleted by this time. Would that happen or not?
The float is 6 hrs away from me, so it's a decent trip to replace the panel, I'd like to try and sort the problem before returning to it. In the meantime I've suggested the battery is removed and kept charged on a separate charger.
I also wonder if I connect the panel/controller output directly to the battery terminals would be a better option.That way the circuit in the breakaway box would be bypassed....wouldn't it?

Don.

Yes I would connect straight the battery as you don’t know what the other electrical circuits are doing even though they are supposed to regulate the charge from the vehicle

Maybe your original controller is putting out a higher voltage than it should?
Is it going into float mode?

Without a calibrated meter, it’s hard to get proper readings

As mentioned when you buy something cheap don’t expect the world

The controllers Jaycar sell are at least of half decent quality for the price from my experience
My controllers (exactly the same as Jaycar sell) I bought off eBay three or four years ago (for a third of the price), I checked the voltage when I installed them
All units are on the original batteries and doing what they should (giving the animals a zap when needed)

My advise (take it with a shot of your best hooch as required)

Get a new controller ($15 ain’t gunna break the bank)
Mount it somewhere away from the panel (as mentioned by Oddiseyman)
Check your meter (against at least one other (poor mans calibration))
Take a packed lunch (maybe even a swag and dinner) and a new battery
Hook directly to battery and test
Leave it for a couple (beers or hours)
Retest and hope for the best[emoji12]

Thanks for your help with this Gav, when you say calibrated meter, I have a digital multi meter does that count?
As for getting it to float stage,I didn't get it hooked up first thing and the sun went down by the time I got back to it. I'll give it another go over the weekend and watch carefully. A trip to Jaycar is also on the list.
Thanks again.
Don.

As i have found, just test the same battery with a couple of meters at the same time and see if there the same
I’ve sent multimeters in for calibration only to find they were out when I got them back

For maximum output best to mount the the controller close to the battery. You see eBay panels where the controller is mounted on the frame of the panel.

Cheers