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  Topic Review (Newest First)
08-20-2010 01:03 PM
malovich this should be simple and ample enough, dead power supples are easy to find, they usually aren't really dead. pretty easy to check to see if one has a working 12v out
How to Convert a Computer ATX Power Supply to a Lab Power Supply - wikiHow
08-20-2010 11:55 AM
nickmerc I you are really concerned about the power available from your supply, I have an old 30A Shipwright power supply I just replaced with a new intelligent charger. I think it would cover all of your DC needs. If interested, pm me.
Lashay cam
08-18-2010 09:49 PM
redline The power supply should do fine for your intended use, as long as you are aware of inrush or start-up currents.

I did exactly that with an Astron 20A regulated power supply, only to find that it could not handle the start-up surge of the fridge, which only consumes 5A while running. But within its limits, it worked fine. (fridge = cold beer during cleaning/waxing, before anyone gets off topic with that).

Now I just leave the batteries in (4 Group 27 on a 3-stage "intelligent" charger) because it's much easier on my back. It does get cold on the shores of Lake Champlain in winter, but the batteries and charger have not complained.

I would put a multimeter on the output when you first connect it, and make sure it can handle your loads, just in case. Also measure the output in AC, to check that it is as regulated as they claim.
08-16-2010 08:15 PM
mitiempo I won't bother you with why you live that far north. But do you really sail up there?
08-16-2010 06:22 PM
Well…… this has been an interesting conversation to say the least.
I waited a few days to respond to think about it. Not sure why this seems to have become a bit confrontational. And I apologize if this sounds like a rant. It is not meant to be.

I read the Sailnet forums religiously and have learned many things over the years from the wisdom of those with much more experience and knowledge than I.

Thank you everyone.

kd3cp ….. Actually, I did identify the unit. "Tripp Lite 3 amp power supply." It’s not like they make 20 different 3 amp power supplies.
The link Hartley gave in his first response takes you right to it. (thanks Hartley)

And thank you kd3cp for your valued opinion that this make of Power Supply is poorly made. I would have thought that the avionics shop that sold it to me to power up a $2K gps unit would have suggested something better built. …..Now I know. (I’m not being sarcastic)

For the record, I had not planned on leaving this unit powered on for more than an hour or two. I did not perceive it as a long term power source. I do not leave my extension cord lying out in the weather for long periods of time. So I routinely (when I leave the boat after working on a project that requires power) unplug the boat and bring the extension cord in. (yes call me anal ….. It‘s the way I do things) I tell you this so you know that there was no chance of leaving it powered up.

So, since kd3cp seems so passionate about how unwise it would be to use this unit, I will not use it.

Now, everyone just take a breath and try to trust me on why I take my batteries out of the boat for the off season. kd3cp and sailingdog…..there are reasons why a person might want to take their batteries off their boat. It’s not about bad advice, it’s about what works best for me.

I must admit, I’m baffled at this turning into an argument about taking batteries off a boat (I feel like I’m being called stupid)!

My boat is a 27ft minimal electronics “kiss” system.

I have two group 24 batteries.

I bring the boat home every winter. Why? It can snow 4 or more feet of heavy wet stuff in one night. Then it could start to rain. (think of the snow as being like a sponge…..oh my! ) Every year someone loses a boat up here due to snow / rain load.

I did the “leave the boat in the water” thing a few years. Left the batteries on the boat with a trickle charger. But it’s hard to find responsible people to watch and shovel your boat when it is left in the water. (And you always wonder if when they shovel snow, do they have the same respect for your deck and bright work that you do?). Watching the batteries, shoveling snow, etc..... isn't cheap.

The closest harbor is 90 miles away from where I live. There is only one road to get to the harbor is and it goes through a two mile tunnel that restricts traffic hourly so that there is only a 15 minute window on the hour to drive through it. And it is completely closed from around midnight to early morning. Not exactly handy.

Can’t you understand why I might sleep more soundly in the winter knowing that my boat is high and dry in my back yard? Sure, some boats stay in the water up here. But the vast majority are taken out if there is anyway for them to do it. One disadvantage is that the boat no longer has the heat sink of the water. The boat gets a lot colder out of the water. Very big boats have no choice, I do ….. So now I take it out.
It can snow a lot in my back yard too….. And as I have said before, it can (though it hasn’t been as cold the last couple of winters) get more than 25- 35 degrees below zero F.

I have made a very strong braced tarp system that covers the boat and sheds most of the snow off.

We get wind storms in the winter. The wind might blow for days 30 to 40 with gusts to 70mph. Once close to 100. I lost shingles off of my roof last winter.
I have found that if you put enough tie downs on the tarp system it will survive the wind storms.
But this tarp system tied up and buttoned up on the ends restricts mid winter access to the boat. I could dig my way out there and untie the tarp and crawl in the boat but it’s not something I care to do any more than I have to.

The best place on my property to keep the boat is more than 6o feet away from the house so it takes a fairly long extension cord . There are the worries of having the extension cord get buried under the snow and possibly damaged or short out. I have moose that wander through my yard (even in the winter) I’d think all it would take is one hoof coming down on the extension cord and it would do the cord in. How about plowing or shoveling the snow?….. Another possible accident waiting to happen. This morning I found brown bear poop in my yard. Hmmm... let's not think about what gentle ben might do if he got tangle up in a cord lying out there.

Leaving a cord out is just not a good idea. I suppose I could get an electrician to put in buried cable and have a hard wired power plug put in out there. Sounds expensive to me.

Would it shock you to know that after I wrap my baby up in late October, I may not go back aboard again till March? Kind of a long time to hope that the trickle charger system is doing it’s thing. Having nothing on the boat that can freeze or short out gives me peace of mind.

Why not a solar charger? I’m at latitude 61.5 N. sailingdog, it may have been you that told me a year or two back that I’m not going to get much output from solar up here….. Especially in the winter with only 3-4 hrs of mid winter sun (not to mention if the solar unit got buried in snow or is blown away.)

Does anyone of you see why I have chosen not to leave the battery on the boat with a trickle charger on it ?

For me, it seems an easy choice to take 15 minutesand pop the batteries out of there and put them in my workshop.


They end up right next to my lawn tractor battery and my airplane battery. That way, I can personally monitor them from the ease and comfort of my heated shop. It’s not a matter of who gave me the advice to do this. It’s a matter of me knowing my circumstances. Sometimes you guys jump to assumptions a little too quickly. You are going to have to give me much more compelling evidence to change my mind about taking my batteries off my boat.

Taking my batteries off my boat has nothing to do with my original question.

My method is how I can get a battery to last many many seasons. Yeah, I know some guys that leave their battery on their boat up here….. These are some of the same guys that find out something happened a month or so back and the trickle charger stopped working. …….. Yep…..and they are buying new batteries every few years. (I’m talking about people up here…. Not in more moderate climes)

Another reason I like to do things the way I am doing it is that when I go to Hawaii for a month or more in the heart of winter, I don’t have to ask my house sitter to keep track of a battery on a boat.

My original question was posed just because I was thinking lazy….. And thought maybe this little power supply could have a use and spare me the few minutes to carry a battery back on board. Not a big deal…. But as has been pointed out…… electronically safer. (though moving batteries has it’s own risks eh?)

Now guys, don’t start in on me with a tirade on why would anybody want to live where I do…… pictures are available on request..
08-13-2010 01:28 PM
hellosailor It all depends on exactly what you have.
"I have 3 amp trip lite dc power supply that puts out 13.8 V." A lot of those were marketed so you could use a "car" device at home and a lot of those were built pretty robustly. I used to have one (home made) installed in a 7-up can and if you put too much load on it, the only thing that would happen is that the output voltage would drop and things would stop working as the pilot light dimmed out.
Odds are your Trip is built the same way, if you pull too may amps you oversaturate the transformer, the voltage drops, and things stop working. I wouldn't be afraid to use it--but try to make sure whatever you are plugging in does NOT exceed the rating. If you want some comfort on that, put a 2.5A or 3A fuse on the output, so you blow the fuse if you're overloading it.
You could also hook up a cheap DC voltmeter on the output, if you see the output voltage drop below 13.8 (or 13.6) when you are using it, turn something off. Odds are you can draw the output down to 12.x volts before anything gets unhappy, anyway. The transformer might overheat--but probbaly not until hours of overload, so a few minutes probably won't bother it.
08-13-2010 07:01 AM
sailingdog I'd point out that many people do keep their batteries aboard the boat YEAR ROUND, even up in New England. As long as provisions are made to charge the wet-cell batteries and keep them topped of, there is little risk of damage to them. I use a 30 watt solar panel for this purpose and it works quite well.
08-13-2010 06:53 AM
kd3pc Hartley

the OP has not identified which TripLite he has, except that it is 10 years old...they(TripLite) make a range of supplies. Regardless of what the web site says, they are seldom "precision regulated" as compared to other PSs. Marketing 101, they are NOT known for their quality as they like others have downsized, moved assembly offshore, etc, etc.

The decision to use them is entirely up to the OP. I have one running a small QRP rig at the house. The on/off switch is intermmittent (gets hot every now and then) and the 13.8 v fluctuates as read by a fluke meter. The QRP rig is homemade and thus not a big deal if the PS pukes.

To the OP, if batteries are kept charged there is no reason to remove them from the boat...Even in Maine and Alaska, they still use them to start boats/cars/snowmobiles...not sure where the "advice" came from that batteries need to be removed from the boat in the winter..
08-13-2010 01:07 AM
Originally Posted by mitiempo View Post
I agree with kd3pc. It is a low output power supply and will likely choke if it sees a real load like a battery that needs charging.
MIT, I don't think anyone was suggesting this unit be used as a battery charger - since it clearly isn't..

Originally Posted by kd3pc View Post
contrary to what others say, this is not a trickle charger...and while it puts out 13.8 vdc nominal it is most likely not well regulated and is NOT a battery charger. Given it's age and lack of use, you may have bad caps in it as well.
Why would you say that when the web site clearly indicates it is "precision regulated"? Can you get any better regulated than that??

As I see it, there is very little reason he couldn't use it for what he wants, within it's limitations, but, to my mind, he might be better served leaving his batteries on-board and running a battery charger instead.
08-12-2010 10:42 PM
mitiempo I agree with kd3pc. It is a low output power supply and will likely choke if it nears its max output. The cd player can exceed 3 amps by itself probably.
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