Solar Battery Charger permanently connected

[Clearsky]

I'm totally new to boating and any advice would be greatly appreciated. I have purchased a solar powered battery charger with the intention of hooking it up to the battery and leaving it connected permanently (mounting it on the boat).<br /><br />The charger came with a cigarette lighter plug however it does say you can wire it in (just cut off the cigarette lighter plug). My question is are these chargers safe to leave connected permanently?, and if so do I run the risk of damaging the battery or even worse the motor?. I have read through some other posts and I think if I'm reading them correctly it is safe, however I'd rather be sure.<br /><br />The purpose is just to keep the battery charge up during idle times as the boat may not be used for a month or so at various times.<br /><br />Any advice would be greatly appreciated as I really have not knowledge of marine electronic's.<br /><br />Thanks in advance.<br /><br />Grant

 

[cuzner]

Re: Solar Battery Charger permanently connected

You may run into a problem with overcharging, and that will ruin your batteries.Solar chargers will put out up to 17 volts. <br /><br /><br /> Jim

 

[vipzach]

Re: Solar Battery Charger permanently connected

Is it safe to leave it connected? that will depend if it has any kind of smart charging built into it. Meaning, will it cycle off and on and adjust its charging rate. I have never seen a solar charging that would charge like cuzner said (17v), but that doesn't mean that they don't exist, I just have never seen one that would charge near that much.

 

[jtexas]

Re: Solar Battery Charger permanently connected

Assuming it's a 12-volt charger, what's the output? 1 or 2 amps continuous trickle charge would be okay. But make sure it has a built-in diode to keep it from draining the battery when it's not putting out any power.<br /><br />And you'll want to remember to check the water levels every so often.<br /><br />And welcome to iboats!

 

[Paul Moir]

Re: Solar Battery Charger permanently connected

If it's over 15W or so, which is 1 or 2 amps like jtexas says, they make a little controller that prevents damage to the battery. If the literature for your panel doesn't advertise it as being "Smart" or something, you can safely assume it doesn't have one. It's simple to add.

 

[Silvertip]

Re: Solar Battery Charger permanently connected

They work just fine. I have a small one mounted in the window of my shed to keep my tractor battery topped off during winter months. Works great. It's a very low output unit so a charge controller is not necessary.

 

[tommays]

Re: Solar Battery Charger permanently connected

My alternator stays at 14 volts pretty much all the time ,it does not seem to hurt anything <br /><br /><br />tommays

 

[Boatist]

Re: Solar Battery Charger permanently connected

Without knowing the output wattage or amps no way to give an answer.<br /><br />The better solars chargers have two thing just like smart battery chargers. They have a diode to prevent the panels from draining the batteries at night. They have some sort of voltage regulation. On very low wattage panels voltage regulation may not be required.<br /><br />Panel will not charge for more than 10 hours at most in the middle of summer. Full output at best from 10AM to 2PM in summer and less in winter so low wattage should not over charge.<br /><br />You can not compare it to a alternator as a alternator has a voltage regulator just like a smart charger and also has output diodes to prevent battery drain when not charging.

 

[Clearsky]

Re: Solar Battery Charger permanently connected

Thanks for all the info, it's amazing..<br /><br />It is designed for 12V batteries and is a trickle charger, as for the output it says "100 mA Solar Maintainer".<br /><br />It' also makes a statement "Will not overcharge!", but cannot see any mention of any built-in diode, it's does have a light on the maintainer which goes on when charging, however this could just indicate it has sufficient light to work, rather than not charging due to battery being full.<br /><br />As suggested, I'll keep an eye on the water levels.<br /><br />Thanks for all the advice.

 

[ZmOz]

Re: Solar Battery Charger permanently connected

100ma will not cause any problems what so ever. It will only be producing 100ma during peak hours on the sunniest days. All other times 0-50ma would be more likely.

 

[JohnRuff]

Re: Solar Battery Charger permanently connected

I love solar cells! But - there is a lot to know about them. For instance -- you need to keep a load on them if they are receiving light. To not have a load on them -- will over time destroy them. So if your charger is connected 24/7 and your boat battery gets fully charged, your solar panel is no longer under load. One way producers have solved this is to switch the output when fully charged, from the battery to a lightbulb (for example). Some units even switch it over to a large power resistor. For example -- a solar panel that is left under sunlight for one year without a load can be expected to lose a minimum of 20%+ of its output.<br /><br />Another note -- make sure there is a circuit (diode) to not let the unit back feed from the batter at night when the panel is not getting any light.