Solar an Zincs

[Tri]

I have the feeling that the Zincs are being eaten up by the use of a Solar system on board. Is that possible and if so what to do?

[Drift Woods]

Great question, I just installed solar last week and I was wondering the same thing. My last boat had an electronic system to stop electrolysis and I was advised not to leave the charger plugged in 27/7

[unclemack]

This would seem to suggest that the solar industry sees galvanic corrosion as a serious threat to installations

https://www.civicsolar.com/resource/...-installations

The average battery voltage is presumably now slightly higher than before so any pre-existing leakage path to prop, zincs etc. might have greater effect on zinc loss?
Just a guess, be interested to learn what you find out.

Good luck, hope someone with a voltmeter can help you resolve it.

[Paul Elliott]

Originally Posted by unclemack

This would seem to suggest that the solar industry sees galvanic corrosion as a serious threat to installations

https://www.civicsolar.com/resource/...-installations

The average battery voltage is presumably now slightly higher than before so any pre-existing leakage path to prop, zincs etc. might have greater effect on zinc loss?
Just a guess, be interested to learn what you find out.

Good luck, hope someone with a voltmeter can help you resolve it.

The link above is referring to galvanic corrosion between the aluminum solar panel rails and the mounting hardware -- *not* the type of corrosion that leads to zinc loss. Also, battery voltage should have virtually nothing to do with zinc loss, unless there is some serious miswiring or leakage going on.

If your solar panels let you disconnect from shore power, they should improve the zinc erosion. Doing that certainly helped preserve my zincs. Just having panels shouldn't have any effect on the zincs. If you are seeing more zinc erosion that usual, you might look at any surrounding boats or changes in the marina wiring. If you are on a mooring, or at anchor, look for wiring problems. If you are plugged into shore power consider adding an isolator if you don't already have one.

[Tri]

I personally don't have shore power on board but there still seems to be a lot of galvanization going on.

The boat is hardly ever in a port.

[a64pilot]

Really unless I misunderstand, you must have a wiring issue that is allowing a path for DC positive to ground, this may have been as a result of your Solar install, but it is not due to Solar, there is nothing inherit about Solar that would cause a current "leakage"

A way is to turn every thing off, so that nothing is drawing power, then disconnect and measure the amperage draw from the batteries by inserting a multimeter in line with the positive cable, if there is any current, start disconnecting circuit breakers till the current draw goes away, then you have found the circuit that may be the problem, of course some circuits draw a tiny bit of current to keep clocks set etc., too.

Or hire a an electrician to find your leakage, there are ways to measure it to that a Marine electrician may have, a reference electrode I believe its called, but the "leakage" can be measured, and or determined if you have a problem or not.

On edit, read this

assets.fluke.com/appnotes/electricalpower/B0269b_u.pdf

[fstbttms]

Originally Posted by Paul Elliott

The link above is referring to galvanic corrosion between the aluminum solar panel rails and the mounting hardware -- *not* the type of corrosion that leads to zinc loss. Also, battery voltage should have virtually nothing to do with zinc loss, unless there is some serious miswiring or leakage going on.

Galvanic corrosion is absolutely one of types of corrosion that zinc anodes provide protection from, and therefore would cause anode depletion. But you are right; without some other underlying problem, a solar charging system should have no effect on anode wastage.

[Paul Elliott]

Originally Posted by fstbttms

Galvanic corrosion is absolutely one of types of corrosion that zinc anodes provide protection from, and therefore would cause anode depletion. But you are right; without some other underlying problem, a solar charging system should have no effect on anode wastage.

What I was trying to say is that galvanic corrosion between the aluminum panel frame and the stainless mounting hardware will not affect the zincs, since it is contained between the panel and the mount.

Yes of course galvanic corrosion between differing underwater metals can deplete the zincs and erode props, through-hulls, etc., as can shore power ground issues.

[fstbttms]

Originally Posted by Paul Elliott

What I was trying to say is that galvanic corrosion between the aluminum panel frame and the stainless mounting hardware will not affect the zincs, since it is contained between the panel and the mount.

Roger that. Just trying to clarify for those among us who consider "electrolysis" (which is a misused term when discussing metal corrosion in boats) to be the only reason we install anodes to protect against.