15Wp panel to battery without controller

[AzRoute66]

what about this scenario..youre off grid.its cloudy all day and your batteries are low. Your one 12v /25 watt panel usually produces 22v more or less, its cloudy and only producing 15v all day. Can you safely hook up that one panel directly just to get your battery bank charged up fully?

I think the answer would be that if you can monitor the voltage at the terminals and terminate it before overcharging it is safe, even if the panel is receiving good sunlight. Since I haven't done it, let's call that a guess. I think the problem with your question is that you didn't say what size/type battery you were charging.

[kdaddy1980]

say you have 16 25w panels (400w/28a) and twelve 73ah lead acid batteries.could you hook them all or a portion of them directly to achieve a "quick charge" on a cloudy day?

[AzRoute66]

What is up with the repeated 'cloudy day' proviso? How do you feel that impacts the question? Once answered, will you ask again about sunny days?

[Mike90250]

There is no "quick charge" on cloudy days. your 400w of panels would produce 40w.