I have searched on the solar topic and it seems most are content to charge their batteries by running the engine or plugging in to shore power. My E38 will reside on a mooring so shore power is not an option. Most seem to speak of running the engine for an hour or more to keep the batteries up when out with the boat. Running the engine for any longer than needed to get in and out of the harbor seems the opposite of why I sail.... I don't want to listen to a diesel engine while I SAIL, which is the whole point of having a sailboat. That said I would like to install a fairly substantial solar system to maintain the batteries. Not these weak 5-15watt panels but something in the 100-200watt range that will easily recharge the batteries while on the hook and partially offset the electrical demands when we are onboard for weekends. I understand that a solar system will still need occasional engine based charging but it should required much shorter durations. Any thoughts on this appreciated. Thanks, RT
Rocinante33
Contributing Partner
solar panels
RT,
We found this supplier on the web & prices look reasonable for the BP solar panels. Check it out. We plan on doing some comparison shopping in the future, too.
Keith
E-33
Rocinante
http://www.suncowboy.com/
RT,
We found this supplier on the web & prices look reasonable for the BP solar panels. Check it out. We plan on doing some comparison shopping in the future, too.
Keith
E-33
Rocinante
http://www.suncowboy.com/
Graham Cole
The Zoomer
we just installed 2 shell solar pv panels on our Riviera 43 and were stunned by the output. Granted the panels were 4.5'X3.5' and fit on the hard top (couldn't do this on the 30+!) but we get 15 amps + on perfect days and about 1.2 when overcast. Never thought that they would be this good. This boat has 2 dc fridges and big electrical demands on 6 6v. batts. Very impressed.
Gary Freeburg
Member II
I put solar panels on my boat years ago and was very pleased. Solar Inc. out of San Diego, will take your load requirements and design a system that works. They were very reasonable.
Gary
SV Katmai
E27
Gary
SV Katmai
E27
NateHanson
Sustaining Member
I've been looking at this for my boat, since I don't have an auxiliary engine, and the 8hp outboard alternator kit is pretty small. Good sources I've looked into are:
www.altenergystore.com
www.affordable-solar.com
www.earthsolar.com
I've emailed a couple of them, and they're very helpful in designing systems for your needs.
www.altenergystore.com
www.affordable-solar.com
www.earthsolar.com
I've emailed a couple of them, and they're very helpful in designing systems for your needs.
Last edited:
Gary Lerner
New Member
solar panel
I think I can give you some pretty specific advice on this one. One year ago I was exactly in your shoes. We had bought an '82 Ericson 381 from a power crazed PO who had installed 5 batteries in the boat with a total of almost 500 amps. He used shore power but we kept it at a mooring and found that typical use of the engine was inadequate to keep the batteries charged. So we went the solar route.
I bought a kyocera 4.7 amp rigid panel and found it nestles perfectly between the grabrail in front of the dorades and the back of the forward hatch. (I am assuming the deck layout of the 38 and 381 are indentical.) This is the one location that no one seems to miss. We paired it with a flexcharge controller, which is a superb device, and found the setup more than adequate to keep our system fully charged. Of course "adequate" depends on how much juice you need and how long you're out. We tend to be day sailors. You can get even more power with the panel on the stern rail but we haven't needed it.
If you feel comfortable with fairly simple DC electrical work, it's a single weekend do-it-yourself project. We just use the engine to get out of the mooring field and then let that big Genoa do all the work.
I think I can give you some pretty specific advice on this one. One year ago I was exactly in your shoes. We had bought an '82 Ericson 381 from a power crazed PO who had installed 5 batteries in the boat with a total of almost 500 amps. He used shore power but we kept it at a mooring and found that typical use of the engine was inadequate to keep the batteries charged. So we went the solar route.
I bought a kyocera 4.7 amp rigid panel and found it nestles perfectly between the grabrail in front of the dorades and the back of the forward hatch. (I am assuming the deck layout of the 38 and 381 are indentical.) This is the one location that no one seems to miss. We paired it with a flexcharge controller, which is a superb device, and found the setup more than adequate to keep our system fully charged. Of course "adequate" depends on how much juice you need and how long you're out. We tend to be day sailors. You can get even more power with the panel on the stern rail but we haven't needed it.
If you feel comfortable with fairly simple DC electrical work, it's a single weekend do-it-yourself project. We just use the engine to get out of the mooring field and then let that big Genoa do all the work.
Thanks Gary Lerner!
Thats the kind of info I was looking for. 4.7 amps puts you at about an 85 watt panel, correct? I was thinking between 80 and 100 watts would do it. On the charge controller, how do you control what batteries get charged? Multiple Flexcharge units? The boat I am buying has two house batteries tied together and a separate starting battery. I have looked into another brand of charge controller that is basically two chargers in one to handle both banks at the same time. How do you do it? I may do two smaller panels on the aft rail. removeable if needed. 12volt work is no problem. Thanks, RT
Thats the kind of info I was looking for. 4.7 amps puts you at about an 85 watt panel, correct? I was thinking between 80 and 100 watts would do it. On the charge controller, how do you control what batteries get charged? Multiple Flexcharge units? The boat I am buying has two house batteries tied together and a separate starting battery. I have looked into another brand of charge controller that is basically two chargers in one to handle both banks at the same time. How do you do it? I may do two smaller panels on the aft rail. removeable if needed. 12volt work is no problem. Thanks, RT
Gary Lerner
New Member
Solar panels
Yes a 4.7 amp panel would deliver 80 watts. As far as size goes let me give you my non-expert understanding of the facts. Your starting battery requires minimal charging and is rarely a problem. I'll assume your two house batteries are about 200 amps together. Typically the usable amperage from the batteries is about 30-40 % of the total or 60-80 amps in your case. This is because it's not healthy to discharge batteries much beyond 50% on a regular basis and most batteries are usually charged back to 80-85% of the total. So you would need approx 80 amps of solar power to recharge your batteries after they are discharged.
I sail at a similar latitude to you out of the North Shore of Long Island. Even with a worst case assumption of 3-4 days of rain in a week the 4.7 amp panel will generate about 80 amps so it would typically recharge your batteries once weekly and often more depending on the weather and season. And remember, you're not throwing out your alternator so that will add to the charging. If you're not using big ticket items like refrigeration or extensive autopilot one panel may be enough.
I have the flexcharge PV7D controller. It has primary and secondary charging outputs for two banks. However, only the primary utilizes charge regulation geared to it's attached battery. The secondary output just mimics the primary. I prefer to use only the primary output and connect it to the line coming from the alternator to the electrical panel. I then use the main A-B switch to determine which bank is charged. This way the flexcharge algoithm fully charges each battery. Since one of your banks is the starter battery which has minimal requirements, I think the second approach would do the trick.
Good luck.
Yes a 4.7 amp panel would deliver 80 watts. As far as size goes let me give you my non-expert understanding of the facts. Your starting battery requires minimal charging and is rarely a problem. I'll assume your two house batteries are about 200 amps together. Typically the usable amperage from the batteries is about 30-40 % of the total or 60-80 amps in your case. This is because it's not healthy to discharge batteries much beyond 50% on a regular basis and most batteries are usually charged back to 80-85% of the total. So you would need approx 80 amps of solar power to recharge your batteries after they are discharged.
I sail at a similar latitude to you out of the North Shore of Long Island. Even with a worst case assumption of 3-4 days of rain in a week the 4.7 amp panel will generate about 80 amps so it would typically recharge your batteries once weekly and often more depending on the weather and season. And remember, you're not throwing out your alternator so that will add to the charging. If you're not using big ticket items like refrigeration or extensive autopilot one panel may be enough.
I have the flexcharge PV7D controller. It has primary and secondary charging outputs for two banks. However, only the primary utilizes charge regulation geared to it's attached battery. The secondary output just mimics the primary. I prefer to use only the primary output and connect it to the line coming from the alternator to the electrical panel. I then use the main A-B switch to determine which bank is charged. This way the flexcharge algoithm fully charges each battery. Since one of your banks is the starter battery which has minimal requirements, I think the second approach would do the trick.
Good luck.
Capn Geoff
New Member
I'm new to the group but noticed the discussion about solar panels. I have a 1989 E38-200 that I bought 2 years ago and it was very over equipped. I've spent a lot of the last two years (when I wasn't shipping the boat cross country) removing superfluous gear. However, one thing that I've grown to love is the twin solaer panels. I don't have details with me but if anyone is interested an get them from the boat. However, they suppy about 8 amps on a good day. This makes us largely independent of shore power and running the engine, except as a normal part of coming and going. They are mounted obove the bimini, where they are pretty much completely out of the way, and have the added advantage of stiffening the (soft) bimini structure. We are, admittedly, quite careful with power when sailing (for example, I use a $10 home depot garden solar light as an anchor light, which saves me almost an amp during night hours), but we don't go short of needed power.
Geoff
Geoff
NateHanson
Sustaining Member
Tell me more about your Home Depot Solar Anchor light! Do you just leave it attached to the masthead, and it's always on after dark? Or do you have it in the rigging? Does it have enough capacity to stay lit until dawn?
Gary Lerner
New Member
solar panel
Thanks Geoff. That a brilliant example of dual use technology. I presume the bimini ends well aft of the boom so the the panels are well out of harm's way. Are they mounted to the the bimini frame? How easy are they to remove when the frame comes down? It would be great if you have some pictures.
Gary
Thanks Geoff. That a brilliant example of dual use technology. I presume the bimini ends well aft of the boom so the the panels are well out of harm's way. Are they mounted to the the bimini frame? How easy are they to remove when the frame comes down? It would be great if you have some pictures.
Gary
Hi,
Can't resist any longer. Thinking back to my first cruising days many years ago, no one I knew (we're talking mid to late 70's) ran anchor lights off house batteries. We all had 6 volt dry cell lights we hung forward, and these often had a solar switch to turn them on and off.
It appears they have become a bit hard to find, but doing some searches, check out these MARINE GRADE anchor lights:
http://www.foreandaftmarine.com/ANCHORlight.htm
They've got what looks like a bargain by McDermott for $16 new. They also have a more sophisticated light by Guest. Now, I know the fancy light by Guest for $119.00 will make you cringe. So, if you don't have a local used marine place handy, call Bacon's - their website is www.baconsails.com (410-263-4880) They have a pile of the Guest lights ranging from about 10-25 dollars depending on the condition. I got one like new for under $20 with spare bulb etc - don't think it had ever been used.
Just a thought, as my gut tells me these will last longer being made for marine use. Also, if you have a really bored CG or marine police on your hand, I don't think they can give you a hard time about using one of the above as an anchor light. I think they could give you a reprimand if they felt like it for something that isn't approved (there are visibility requirements on your anchor light, and who knows if the Home Depot solution meets them....)
-David
Independence 31
Emerald
Can't resist any longer. Thinking back to my first cruising days many years ago, no one I knew (we're talking mid to late 70's) ran anchor lights off house batteries. We all had 6 volt dry cell lights we hung forward, and these often had a solar switch to turn them on and off.
It appears they have become a bit hard to find, but doing some searches, check out these MARINE GRADE anchor lights:
http://www.foreandaftmarine.com/ANCHORlight.htm
They've got what looks like a bargain by McDermott for $16 new. They also have a more sophisticated light by Guest. Now, I know the fancy light by Guest for $119.00 will make you cringe. So, if you don't have a local used marine place handy, call Bacon's - their website is www.baconsails.com (410-263-4880) They have a pile of the Guest lights ranging from about 10-25 dollars depending on the condition. I got one like new for under $20 with spare bulb etc - don't think it had ever been used.
Just a thought, as my gut tells me these will last longer being made for marine use. Also, if you have a really bored CG or marine police on your hand, I don't think they can give you a hard time about using one of the above as an anchor light. I think they could give you a reprimand if they felt like it for something that isn't approved (there are visibility requirements on your anchor light, and who knows if the Home Depot solution meets them....)
-David
Independence 31
Emerald