Hi from Greece

[Sotos74]

Hi I,m sotiris from Greece i.m new into solar systems and have questions about a portable system I have .
I have a Chinese loskii generator rated at 12 to 24 v input charging and a Chinese imars panel rated at 23.7v max charging voltage 135watts output max .so the first minutes when I plug the panel to input it reads 50 to 60 watts charging power during a relativly sunny day but then gradually decreases to around only 30 watts while panel is warming up .
I need your help about what happens ..any suggestions?
Thanks in advance !

 

[Ted Katsouras]

Sotiri, my guess to your problem is that the Loskii generator does not have MPPT in the solar imput to optimize for solar panel output.

 

[Sotos74]

Hi again !
Thanks for your reply .But I want to rephrase my question ..First on the box of the generator says it has mppt but it is chinese so it may be a lie .And second the phenomenom happens always on the first one minute every time I plug in the panel Should be the case of overvoltage protection ?I mean since the panel warms up and increase output an overvoltage protection kicks in and cuts input power readings ?

 

[Ted Katsouras]

I will say to check if this is coming from the solar panel, check on the specs the temperature coefficient of the panels you are using. Another simple way in testing will be let the panels worm up so you see the power drop then sprinkle water on the panels to bring the temperature down, if the problem is on the panels you should see the power going up as the panels are cool.

 

[Don B. Cilly]

Hi from (an Italian living in) Spain. (which - all the way to Greece - pretty much cover the Mediterranean ;·)

So your "generator" is just a portable inverter-solar charger, right?
And you get 60W (5A at 12V) for the first minute or two of charging, then it drops to half of that, right?

Well, out of 135W rated, you should get some 90-100 with the sun at a good angle, so 60 is pretty low to start with.
Then, it's (very) true that as temperature goes up, panel efficiency goes down... but not by that much, and not in such a short time.
And they'd be hot to start with - from the sun itself.

First thing I would do is get an ammeter (they're really cheap) and put it between the panels and the "generator".
So you "see" what goes on with your panel, and how the MPPT deals with it. Analog ammeter would be best, but digital will do.

Then, if it confirms what the thingy says... try another panel. They're cheap enough, and you can always parallel them for added power.
Chances are - from what you're saying - that panel isn't all that good.

Unless, of course, your battery is fully charged to start with, in which case the MPPT is just doing its job.

 

[Sotos74]

Hi from (an Italian living in) Spain. (which - all the way to Greece - pretty much cover the Mediterranean ;·)

So your "generator" is just a portable inverter-solar charger, right?
And you get 60W (5A at 12V) for the first minute or two of charging, then it drops to half of that, right?

Well, out of 135W rated, you should get some 90-100 with the sun at a good angle, so 60 is pretty low to start with.
Then, it's (very) true that as temperature goes up, panel efficiency goes down... but not by that much, and not in such a short time.
And they'd be hot to start with - from the sun itself.

First thing I would do is get an ammeter (they're really cheap) and put it between the panels and the "generator".
So you "see" what goes on with your panel, and how the MPPT deals with it. Analog ammeter would be best, but digital will do.

Then, if it confirms what the thingy says... try another panel. They're cheap enough, and you can always parallel them for added power.
Chances are - from what you're saying - that panel isn't all that good.

Unless, of course, your battery is fully charged to start with, in which case the MPPT is just doing its job.

Thanks for your kind and extensive reply !!In fact I really don t know if it is a battery/generator or panel problem ...the generator if a panel or wall plug is uplugged and plugged again in seconds it refuses to charge ...it shows only 3 watts charging ... also the generator when I power on the ac port it shows consumption 11watts without any device .... unfortunately I haven't noticed if this was happening from the beginning ...and this constitution goes down to 3watts when solar input is plugged in .....strange things happening or I know nothing about solar systems or a Chinese worker messed up wiring !!

 

[Sotos74]

Thanks for your kind and extensive reply !!In fact I really don t know if it is a battery/generator or panel problem ...the generator if a panel or wall plug is uplugged and plugged again in seconds it refuses to charge ...it shows only 3 watts charging ... also the generator when I power on the ac port it shows consumption 11watts without any device .... unfortunately I haven't noticed if this was happening from the beginning ...and this constitution goes down to 3watts when solar input is plugged in .....strange things happening or I know nothing about solar systems or a Chinese worker messed up wiring !!

......or it is a panel problem as you said

 

[TomC4306]

Unless, of course, your battery is fully charged to start with, in which case the MPPT is just doing its job.

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