Solar panel damaging battery?

[Mad Harold]

I was recently given a 10W solar panel by a fellow moorer having a clear out.Was told that only being 10W there was no need for a controller.

The boat is now going to be left for some time,so I thought it might be prudent to disconnect it.

When connected to the panel,the battery voltage reads 14V.Connecting the voltmeter to the solar panel it reads 1V.

I thought that I should disconnect the solar panel from the battery and cover the solar panel,but the reading on the voltmeter with the panel covered was 6V.

Most puzzling,so did it again with the same result.

Been told that leaving a solar panel disconnected in the sun will damage it.

Two questions,will disconnecting the solar panel from the battery damage the panel?

Will leaving the solar panel connected to the battery damage the battery?

As the voltmeter reading on the battery is 14V,I assume the battery is fully charged.

Thanks for any advice..

[Tony Brooks]

To be  sure I would want to know exactly how an where you connected the voltmeter to the panel and if the panel was in bright daylight.

 

I am sure leaving the panel disconnected will not damage it.

 

10 watts is within what used to held to be safe to connect to a typical inland boat bank without a controller. It is unlikely to produce more than the self discharge rate of a larger bank - less than half an amp.

[WotEver]

22 minutes ago, Tony Brooks said:

To be  sure I would want to know exactly how an where you connected the voltmeter to the panel and if the panel was in bright daylight.

 

I am sure leaving the panel disconnected will not damage it.

 

10 watts is within what used to held to be safe to connect to a typical inland boat bank without a controller. It is unlikely to produce more than the self discharge rate of a larger bank - less than half an amp.

Agree with Tony. No damage to a tiny (or even large) panel by leaving it disconnected and no damage to the battery if left connected. A 10W panel at midday on the equator would output less than an amp. In the UK never more than half that. 
 

If it was mine I’d certainly leave it connected and it would help counter self-discharge.