Solar Panels

Hello all,

Just wondering if anyone uses solar panels to trickle charge their batteries onboard? thinking about setting up one, planning on installing VHF, GPS/FishFinder combo, marine radio and speakers, nav lights and spot lights so obviously a bit of juice will be used. Just wondering if anyone has any idea how many batteries I'd need, I have one 12v 7ah battery for the e/s outboard and will get another to run all the electronics but will one do? and if it's continuously trickle charged will it work?

thanks in advance!

I've had a pair of paralleled solar panels (Maplin, 2w) clipped onto the boat battery for the last four years, and they keep it tip-top. Your e/s battery is quite small, and several electronic items running at the same time would drain it fairly fast unless its being charged from an alternator, so a second battery is the way to go. A standard 45Ah sealed car battery from say Halfords would give you good margin over a normal-length outing.

Ok so two batteries for my electronics and such you think? well i have the motor as a separate circuit so it keeps its own charge up with the alternator maybe if i put the nav lights on that battery instead? then run my echomap, radio and VHF off the other? well i was looking at getting 10W< so that it has a could chance of charging the battery sufficiently over rest periods. Plus it would trickle charge the battery while I'm using it i think I'd need quiet i high output from the solar panel though to keep that much power going? All lights are LED so low power consumption, I'm assuming that the echomap has low consumption so just mainly the two radio's running off their own 12V?

Thanks

What engine are you running? Must be fairly small if 7Ah starts it? I have a 50HP 4-st on my yoke, and a 60Ah battery starts it and runs radio, sounder, electric tilt/trim etc as well, in conjunction with alternator. I carry a standby 45Ah and switch electronics over to that when fishing with the engine off, so's not to sap the main battery. Probably overkill, but I like to be sure to be sure...

You dont need much output from the solar panels, mine are only 4W total, its having them hooked on the battery for long periods that does it. They'll make almost no impression when you've got lights/electronics etc running.

Ya i've a 60hp Mercury autolube with t+t. I've no idea what that battery is it's back under the transom and i haven't touched it since i bought the boat, i was wondering if a 7ah would run my electronics (beginning to accept that's not remotely possible ) I'd say i'll run the lights off my engine battery just because the alternator will keep that battery tip/top (hopefully).
Ya i want a good output from the solar panel so i can run the two radios and fish finder from anything like six to eight hours from full battery? I'm not sure if the battery would do that anyways or not because my knowledge of circuitry and electronics is not very high!

OK, gotcha now. Ur onboard battery will handle everything while the engine's running and charging (have a look -its probably 45Ah upwards). Ur problem will come when u want to fish with the motor off. Electronics/electrics will be draining the battery at a rate of knots, and the tiny input of solar panels will be no help. Best to have a second battery u can switch over to - 7Ah is way too small - or wire up sounder, radios etc permanently to the 2nd battery (via fuses!) and use the solars to keep this topped up. OR u can just use the main battery for all and leave the engine running.....
In any event, a second battery is always a good thing to have on board. They're not that dear these days.

Oh right I have you! ya it's all bit of a tricky mess really that's why I'm thinking maybe 10W solar panel so its charge rate might be high enough to slow the drainage on the second circuit with the radios etc. The engine circuit i wanna put the nav lights to because i'll only ever be using them when the engine is on and they're all LED's so hopefully the usage is low enough that the alternator keeps the battery fully charged!

Haha well if i figure out something ingenius i'll let you know how it goes..

Go and watch "Apollo 13" again. That's a great training video for onboard electrics......

Hahaha ya i think i might actually get a book of some sort though, wouldn't go astray for future use.. Thanks for all your help as well Hugo!

I carry one of those portable power station/jump starter packs as a backup, mine will start up to a 2L diesel so will easily start (and has done)an outboard. I don't think they are any dearer than a battery. You can even charge them up when the car is running by plugging them into the cigarette lighter/power socket.

You can even charge them up when the car is running by plugging them into the cigarette lighter/power socket.

I've a 12v socket on the boat actually, used it for a spot light but would work for that!

Oh right I have you! ya it's all bit of a tricky mess really that's why I'm thinking maybe 10W solar panel so its charge rate might be high enough to slow the drainage on the second circuit with the radios etc. The engine circuit i wanna put the nav lights to because i'll only ever be using them when the engine is on and they're all LED's so hopefully the usage is low enough that the alternator keeps the battery fully charged!

Haha well if i figure out something ingenius i'll let you know how it goes..

Yes these leds does consume less power and alternator keeps the battery charged.. I am trying to use solar panels but still working on it..

Solar panels are ideal to keep a fully charged battery topped up (trickle charged) they are not suitable to charge a battery with such large amounts of current being drawn from it. I would think about installing two identical sized main batteries and install a switch similar to one of these http://www.chmarine.com/acatalog/Blue-Sea-Battery-Switch---E-Series---Twin-Battery-On-Off-Model-9001e-BS9001E.html

And run everything your engine and electronics off them!!

With this switch you should start the engine in the morning on position 1+2 so using both batteries the minute the engine is running switch to either position 1 or 2 then you are running everything just on that battery leaving the second as your reserve, while both batteries are being charged by the alternator. Should you have trouble starting just switch back to 1+2 to start but make sure to switch back to a single battery each time. You should never encounter battery problems at sea with a set up like this as you have a fully charged battery always in reserve.

Turn it to "Off" when the boats not in use and nothing will be accidently draining the batteries but be careful though if left afloat if you have an auto bilge pump, you need to wire the pump to by pass the switch

WARNING!!!!! It is very important that when you are switching batteries when the engine is running that you never turn the switch to or through the "OFF" position as this will damage your alternator by removing the load from it. The way the switch is designed it's difficult but not impossible to do this, just look at the switch you only turn it 90 degrees from positions 1+2 to 1 or 2. Never turn it 270 degrees or 3/4 of a turn trough "OFF"

Solar panels are ideal to keep a fully charged battery topped up (trickle charged) they are not suitable to charge a battery with such large amounts of current being drawn from it. I would think about installing two identical sized main batteries and install a switch similar to one of these http://www.chmarine.com/acatalog/Blue-Sea-Battery-Switch---E-Series---Twin-Battery-On-Off-Model-9001e-BS9001E.html

And run everything your engine and electronics off them!!

With this switch you should start the engine in the morning on position 1+2 so using both batteries the minute the engine is running switch to either position 1 or 2 then you are running everything just on that battery leaving the second as your reserve, while both batteries are being charged by the alternator. Should you have trouble starting just switch back to 1+2 to start but make sure to switch back to a single battery each time. You should never encounter battery problems at sea with a set up like this as you have a fully charged battery always in reserve.

Turn it to "Off" when the boats not in use and nothing will be accidently draining the batteries but be careful though if left afloat if you have an auto bilge pump, you need to wire the pump to by pass the switch

WARNING!!!!! It is very important that when you are switching batteries when the engine is running that you never turn the switch to or through the "OFF" position as this will damage your alternator by removing the load from it. The way the switch is designed it's difficult but not impossible to do this, just look at the switch you only turn it 90 degrees from positions 1+2 to 1 or 2. Never turn it 270 degrees or 3/4 of a turn trough "OFF"

Ah ok and the batteries are wired in parallel then through the switch is it? this is all so complicated should have paid more attention in engineering class!
Sounds like a perfect idea to be honest but the circuitry and stuff i wouldn't have a notion how to execute. I have a buddy who's an electrician but i'm not sure if he'd be able to do that?

Ah ok and the batteries are wired in parallel then through the switch is it? this is all so complicated should have paid more attention in engineering class!
Sounds like a perfect idea to be honest but the circuitry and stuff i wouldn't have a notion how to execute. I have a buddy who's an electrician but i'm not sure if he'd be able to do that?

Yup both batteries when switched in as 1+2 are wired in parallel I have mine on this system but I have 4 batteries in two banks to give me a 24 volt system on my boat. This switch allows both batteries to constantly charge while allowing just one to supply all the power once switched to either 1 or 2. Some recommend alternating use between 1 and 2 every second trip but it's not that important really, although it's worth changing every now and then to help prolong each batteries life span.

The advantage of this setup is even with two half discharged batteries they will give you enough combined power to start the engine, So you can start on 1, 2 or both so you have 3 lives rather than just 1 like you have now.

It's a no brainer approach really When you're leaving the boat on a trailer just turn it off and that will kill the power to all your electronics so there is no fear of forgetting to switch something off causing your batteries to drain.

Here's a very simple wiring diagram for you: http://www.google.ie/imgres?imgurl=http://i61.photobucket.com/albums/h51/40oldtimer19/Electrics/StandardBatterySwitchWiring.jpg&imgrefurl=http://www.tinboats.net/forum/viewtopic.php?f%3D5%26t%3D24548&h=433&w=454&sz=28&tbnid=sagNK7Ybsmu58M:&tbnh=117&tbnw=123&zoom=1&usg=__xzkgdyAgpzIIFQcBegDUh8ioUKw=&docid=IATwXq-oyxW15M&sa=X&ei=eZxFUs25JYSShgePxoHACw&ved=0CDQQ9QEwAg

Ah ok and the batteries are wired in parallel then through the switch is it? this is all so complicated should have paid more attention in engineering class!
Sounds like a perfect idea to be honest but the circuitry and stuff i wouldn't have a notion how to execute. I have a buddy who's an electrician but i'm not sure if he'd be able to do that?

Yup both batteries when switched in as 1+2 are wired in parallel I have mine on this system but I have 4 batteries in two banks to give me a 24 volt system on my boat. This switch allows both batteries to constantly charge while allowing just one to supply all the power once switched to either 1 or 2. Some recommend alternating use between 1 and 2 every second trip but it's not that important really, although it's worth changing every now and then to help prolong each batteries life span.

The advantage of this setup is even with two half discharged batteries they will give you enough combined power to start the engine, So you can start on 1, 2 or both so you have 3 lives rather than just 1 like you have now.

It's a no brainer approach really When you're leaving the boat on a trailer just turn it off and that will kill the power to all your electronics so there is no fear of forgetting to switch something off causing your batteries to drain.

That's awesome man sound for that, the solar panels were really putting my head in a fizz! Will probably get that, doing a big job on the boat over christmas gonna make it how i like it!

That's awesome man sound for that, the solar panels were really putting my head in a fizz! Will probably get that, doing a big job on the boat over christmas gonna make it how i like it!

You're welcome

The solar panels are really only good to keep the batteries charged between fishing trips so if you leave it on a mooring / marina or on a trailer then they would be useful if say you were leaving the boat sitting idle for a month or more but if you're out nearly every weekend then they aren't much use to you really You can always add some solar panels to the dual battery circuit too if you want to confuse yourself more

That's awesome man sound for that, the solar panels were really putting my head in a fizz! Will probably get that, doing a big job on the boat over christmas gonna make it how i like it!

You're welcome

The solar panels are really only good to keep the batteries charged between fishing trips so if you leave it on a mooring / marina or on a trailer then they would be useful if say you were leaving the boat sitting idle for a month or more but if you're out nearly every weekend then they aren't much use to you really You can always add some solar panels to the dual battery circuit too if you want to confuse yourself more

Solar panels are just awesome.. Bit high cost of installation but still we are able to generate cheap and green electricity.