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diy solar

Does an MPPT solar controller, turn excess voltage into Current/Amps?

When the battery is fully charged, the current drops to zero and thus the batteries are consuming no power. The panels also produce no power when the current is zero, so nothing is wasted. The panels have potential to produce power.

I have long suspected (but never bothered to test) that panels producing power should be cooler than identical panels in the same solar situation that have nothing connected to them. If that is the case, then the answer to your question is that unused potential simply heats the panels. Somebody with an IR imaging system could test this easily by putting two similar panels next to each other in full sun, short one of them, leave the other open, then see if they are at different temperatures.
AFAIK photovoltaic cells don't produce heat, they produce electricity. You suspect if they're not producing electricity they retain more solar heat? I'm having trouble wrapping my head around that.
There are thermal solar panels, but I think those are a different animal altogether.
 
Does an MPPT solar controller turn excess voltage into Current/Amps?

If my solar panels create 21V @ 7Amps and my battery only needs 14.2V to charge. What happens to the excess voltage? Is it just wasted away by dumping into a heatsink or is it converted into additional current/charge?
Man, I dislike it when people reply on questions to prove they are smart, or prove they understand things well, instead of trying to help the person asking the question.

I believe the simple answer you are looking for is: The MPPT can indeed output a higher current to your batteries than the current that is flowing from your solar panels. It will do so to maximize the power throughput from your panels to the battery, while maintaining the correct voltage required to charge your battery.
 
Consider not complaining about what people post - just skip over them if you don't like them.

And the 'excess electricity' is simply not utilized. Current flows or is drawn, it's not pushed.
Why a 5A appliance plugged into a 20A receptacle doesn't blow up.

A battery will only draw what it can, if it needs to charge, up to the limit of the charging output. There needs to be a difference in voltages from one source to another for current to flow from high to low. And why the water analogy works for some.
 
MPPT is a smart DC to DC buck converter. By excess voltage op means panel voltage that is above the battery charge voltage and the answer is YES the MPPT will output more amps and less volts to the battery than it is taking in from the panels and at very high efficiency. A cheap unit I tested earlier today was steady 98.5%.
 
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AFAIK photovoltaic cells don't produce heat, they produce electricity. You suspect if they're not producing electricity they retain more solar heat? I'm having trouble wrapping my head around that.
There are thermal solar panels, but I think those are a different animal altogether.
As already mentioned it is about conservation of energy. Panels would need to be more reflective at no-load if they don't heat up more.

AFAIK Internal mechanism for heating is roughly following: Electrons(current) is generated in the P-N junction of the solar cell even if there is no load. Voltage is limited by the forward treshold voltage of the silicon PN junction (diode) and it is about 0.7 volts per cell. When there is no external load the solar cell is shunted by the forward biased diode. There is same current flowing "internally" even when the panel is not loaded.
 
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