Voltage drop a major issue for solar charging.

A couple of recent discussions and a thread on another forum have highlighted the very dramatic effect of voltage drop in cables in solar charging rigs.

Yeh I know lots of people are aware of voltage drop in low voltage DC wiring.......if there are only 12 or 24 volts and one or two go missing, things don't work so well.

BUT when we look at battery charging in particular solar battery charging, the problem of voltage drop becomes a very serious issue.

when the difference between barely charging at all and charging at a fairly rapid rate can be less than a single volt, voltage losses in solar charging systems could be crippling your system.

A poster on a thread on another board, baught a folding solar panel charging system.....for a very cheap price knowing full well what he was buying and expecting to do a little "tuning".

As well as replacing the hinges and latches with better items and a few minor mechanical tweaks......he replaced the wiring with some considerably heavier cable.
Being someone handy with electrics he had the ability to measure output and the presence of mind to do so before and after.

Before with the package cabled as it came out of the post the performance was disappointing to say the least.....the system delivered nowhere near what the panels output should.
After replacing the wiring and with no change in anything else, the charge current delivered to the battery doubled...in fact the systems deliverd close what is should have in theory.

I had a long phone discussion with one of the exploreoz members....and I agree that he should be doing much better out of nearly 500 watts of panels on top of his motorhome....he's getting nowhere near the 20 odd amps at 24 volts that he should out of this system in full sun.

I know those of us that are informed are well aware of voltage drop but, on solar charging systems, a very small voltage drop could very serioulsy effect your charging efficiency, particularly in marginal sunlight.

Remember too that almost every manufacturer of everything is trying to save money everywhere they can....so they predictably never "go overboard" with the wiring sizes

So...if you are not happy with the charging efficiency in ya solar system...or the figures just don't seem to add up.....maybe you should look at the size of the cables.

AND they probably should be very much larger than may seem reasonable.

A fraction of a volt will chaneg how fast ya batteries charge.

cheers
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