Solar panel connection

[Petercatterall]

I have just installed a small (20 watt) panel, mainly just to keep my starter battery charged. I have connected it directly to the starter battery (via a regulator) so that I can switch off the boat power.

I also intend to connect up the bilge pumps so that when I leave the boat the pumps and the solar panel (and nothing else) is connected.
This will mean that if the pumps are needed they may deplete the starter battery despite the solar panel.

Perhaps I should connect the pumps to the domestic bank (and buy another solar panel for that bank ??!!)

I guess that if there is a serious leak then the boat will sink anyway!
What is the reccomended stratagy in this matter??

As allways thanks for the good advice.

 

[simonfraser]

that size panel may keep your battery happy but no more, if you need to use the pump a much larger panel is needed.

 

[supermalc]

My clinker boat has pumped out about once a day since I got it. Mainly I believe because when it was pulled onto the trailer, the roller rested on a plank, causing a slight leak.

With the large old YSE12 moving sideways on the original wooden mounting rails, this is bound to have exagerated the leaks. Had I not known of other boats that pumped out almost hourly, this would have worried me.

Recently I inquired of a fellow boater and electrician if the batteries would last long. 2 ordinany heavy duty car batteries are wired in series. I believe 80amp hour in total, so if only 25% of that power is available, we have worked out it will stay afload with no top up for at least 6 weeks. Even if it pumps out about 6 times a day.

Shortly when the river level is up to summer levels, and we can access the slip, I'm going to put it on my friends trailer and fill with bitumin and sawdust paste. When I had it on the trailer last year (twice) for a prop change then to take the shaft out to straighten it, I didn't have time to look properly. It had been antifouled just before I got it, but it was on the beach, so leaks couldn't be detected.

So if you have a pump on a starter battery, it will last months, unless of course you get a serious hole, unlikely isn't it on a mooring? I'm also informed most boats sink due to rainwater, not leaking hulls.

 

[Anonymous]

I'm surprised that you have chosen to connect the solar panel to the starter battery rather than the domestic. Normally starter batteries look after themselves unless they are at the end of life. 20W is not a huge panel, but it will give nearly 2A which is useful and surely better in the domestic battery?

As for the bilge pump question, is yours a dry boat? If you don't take much water then why leave the pumps on at all? Turn off all seacocks and a squirt of grease into the stern tube and you ought to be fine. If your boat is so wet that it needs regular pumping then maybe you would be better off curing the leaks.

 

[LORDNELSON]

Re:Yes but.......

I use a solar panel to top up my starter battery on the basis that the boat is kept on a swinging mooring and there is thus no shore power with which to float charge. Any battery looses stored energy gradually over time and if committments prevent my getting to the boat for a longish period my panel will meet the loss of energy and thus when I next visit the boat I should still be able to start the engine. If the engine starts then the other batteries can be charged. I personally do not like the idea of using a pump on a regular basis to clear the bilges and whilst I leave the pump on automatic (connected to the service batteries) I also try to ensure that there is no, or very little, water entering the bilges.

 

[Petercatterall]

Thanks guys for the various advice.
I have put the solar panel on the starter battery just as belt and braces to ensure the battery is at peak charge for starting. Like 'Lord Nelson' I reason that once started I can charge the domestic bank anyway.
My boat doesnt take in too much water (I do spend a lot of time chasing odd drips) I'm sure that I could leave the boat for a year and still have a dry cabin floor! But I think that things can always go wrong, a sea cock could fail, vandals could remove a hatch etc...anything can happen!!