jim
Full Member
Posts: 41
|
Post by jim on Jul 7, 2014 19:21:44 GMT
I am the proud owner of a new SO439 which has been factory fitted with solar panels. The panels are Solara 12V 45W SM160M producing about 160-180Wh on a typical summer's day with a mix of sun and cloud, which is about 15Ah in a 12V system (info from Solara). If I turn the isolators off there is 'low voltage' battery alarm sounding all the time as the panels produce 9-11v (as per the voltmeter) when the sun shines which triggers the alarm (?). Solara advise to leave the isolators 'on' however on returning to the boat after a week the voltage will have dropped from 13v to 12/12.2v although there are no electrical devices left switched on - everything turned off including bilge pump. This drain of power seems extraordinary and would not have expected it on my old 40.3 after a month - and she did not even have solar panels. I would be very interested to hear from other owners with solar panels what their experiences are and whether they think something is awry.
|
|
|
|
Post by rxc on Jul 7, 2014 19:52:34 GMT
Jim,
Could you describe your solar panel setup a bit more, and explain what the "isolators" are?
I have two 130s panels on my 43DS, connected in parallel to a solar panel controller that is then connected to the batteries. My controller is a semi-intelligent unit that tries to keep the battery voltage up until it thinks that the batteries are fully charged, and then it drops down to the float voltage to maintain them.
Do you have any sort of controller in your system, or do you just depend on some diodes (isolators?) to charge the batteries when the panel voltage is above the battery voltage? If this is the case, I would suspect that maybe one of your isolators has blown and is allowing the battery voltage to flow back into the panels, which is not a good thing.
How do you "turn the isolators off"?
|
|
jim
Full Member
Posts: 41
|
Post by jim on Jul 7, 2014 20:41:53 GMT
rxc
There is a solar panel controller (a 'Solara SR135TL') connected to the electrical system (which has its own Cristec battery charge/controller) but not sure if this solara unit is connected direct to the battery bypassing the isolator switches or not, both have charge/float settings. By 'isolators' I mean the large handle type switches that turn off all the electrics on the boat - one positive each for domestic and engine batteries and one negative that serves both. Apologies but I am no expert in the field of electrics so my terminology may be a little ambiguous but does the performance I am experiencing sound right to you? the boat is covered by warranty but dont want to be brushed off that this is 'normal' and would appreciate your experiences on what your panels can deliver.
|
|
|
|
Post by Don Reaves on Jul 7, 2014 20:59:21 GMT
Clearly, either the system was installed correctly, or one or more parts has failed. It is the purpose of the solar panels to prevent exactly what is happening. That is, you should not see the battery voltage decrease over time if there is no load on the system. In fact, good batteries will hold their charge for weeks without the kind of drop you're seeing if there is no load at all.
Call your dealer and get the system serviced.
Don
|
|
jim
Full Member
Posts: 41
|
Post by jim on Jul 7, 2014 22:23:10 GMT
Don - thanks your comments which echo my own, albeit unqualified, thoughts.
|
|
|
|
Post by Quiddle on Jul 8, 2014 8:10:58 GMT
Definitely not right. Possibly a faulty / missing diode which is allowing the panels to discharge the batteries during darkness. Can you try disconnecting the panels to see if the battery discharge stops?
|
|
|
|
Post by rxc on Jul 9, 2014 17:56:19 GMT
Jim,
Your situation is definitely NOT normal for the equipment you have installed. You should ask the dealer to fix it, and you should also ask him to explain how the system works, as well.
For a good explanation of electrics, Nigel Calder has an encyclopedic book "Boatowners Mechanical and Electric Manual" that describes all the major systems on a modern cruising boat, and how they work. It is very clearly written so that a boater who is not an engineer can understand how things work and use the book to better maintain their boat. I am an engineer, but even I found it informative. It won't give you the details to rebuild your diesel engine (I think he wrote one other book to do that), but the electric explanations are especially good for non-technical owners.
Ralph
|
|
