boat lights no battery

ljcatman

Petty Officer 3rd Class
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Aug 27, 2008
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91
i got a boat about 1 month ago i haven't got a battery for it can i hook up a battery charger to it to see if my lights work or will it blow the fuse. also what wire goes were there's a red one with fuse & a yellow one with a fuse too. and two white wires i don't know were they go. my charger is a sears sensor 10 amp charger. it charges regular 12volts & low maintenance free batteries & deep cycle batteries. here's a picture of the wires let me know which wire goes were



 
D

DJ

Guest
Re: boat lights no battery

The battery charger is fine. Set it to its lowest amp rating.

My GUESS is that the two fused wires are Positive and the whites are Negative.
 

mthieme

Captain
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Oct 6, 2007
Messages
3,270
Re: boat lights no battery

I would not recommend using your charger for this.
Put a battery in.
The ones with fuses are positive, the white are probably negative.
One set is most likely for your bilge pump. The other pair probably goes forward to the fuse panel.
It would be best to trace the wires to be sure.
 

ljcatman

Petty Officer 3rd Class
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Re: boat lights no battery

do i connect both positves together & both negatives too. it has two switches for bow light & rear light
 

achris

More fish than mountain goat
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27,468
Re: boat lights no battery

DO NOT!!!! connect a battery charger up without a battery there :eek: :eek:
The charger needs to 'see' a battery as a load to set itself to the right voltage and current...

From the picture it is difficult to tell which wires go where.... sorry.

Chris.............
 

ljcatman

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Re: boat lights no battery

will get better pictures tomorrow thanks
 

ebry710

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Re: boat lights no battery

I have always used my 12 volt charger as a backup battery. My charger (and most chargers) has a breaker if you get into trouble. I do not use it for sensitive electronics though, but to see if a 12 volt light works it shouldn't be a problem.
 

achris

More fish than mountain goat
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Re: boat lights no battery

I have always used my 12 volt charger as a backup battery. My charger (and most chargers) has a breaker if you get into trouble. I do not use it for sensitive electronics though, but to see if a 12 volt light works it shouldn't be a problem.

This only applies to the old transformer type chargers.. Most modern chargers are 'switch mode' and will not react kindly to being connected to a load (globes, etc) without a reference (battery).

The voltage will rise uncontrolled, or not at all.

Chris.........
 

tashasdaddy

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Re: boat lights no battery

pull the battery out of the tow vehicle for testing.
 

kenmyfam

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Re: boat lights no battery

Should have a battery in place in my opinion. You will need to buy one anyway will you not ??? What else will you be running off the battery ???
 

Silvertip

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Re: boat lights no battery

If you measured battery charger output voltage without a load it would very likely measure much higher than 13 volts. Connect it to a battery or any load for that matter and it's output voltage drops to normal charge levels. It is perfectly safe to use it to check boat lights. In fact I use one regularly when troubleshooting trailer light problems.
 

mthieme

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Re: boat lights no battery

Amperage is going to more of an issue than voltage. The voltage is going to be fairly constant and DC is tolerant of voltage fluctuations. e.g. the lights will work with 10v and they will work with 14v.
You do not want to throw 100 amps at it though, stuff is going to start popping.
I assume when you use your charger for testing, it's set on the lowest amperage (?).
 

Silvertip

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Re: boat lights no battery

Come on folks -- you have a 100 amp battery in the boat. Accessories
DRAW from the battery the current they need. You don't THROW 100 AMPS at the devices. Mthieme - If that were the case every time you flipped a switch you would toast every device that draws less than 100 amps (or whatever size battery you have). You can hook a gauge lamp that draws about .2 amps to a 10 amp battery charger to test it with no damage. If your charger happens to have an ammeter on it you will notice the needle barely wiggles when you light the bulb. The only way you will get full output from a battery charger is to short the output leads or connect a device that draws more current than the rated output of the charger.
 

mthieme

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Re: boat lights no battery

Every charger I've ever had and used surges when turned on and drops in amperage from there. 10 amps isn't much which is why I inquired about your setting. We don't know what kinda charger he has...could be a larger 100 amp shop unit, could be an automatic 55 amp unit, could be a trickle charger.
I maintain that it is better procedure to use a battery and not a charger to test with.
If it works for you, great.
Personally, I test mine hooked up to the tow vehicle and that works for me.
 

triumphrick

Lieutenant Commander
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Jun 26, 2008
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Re: boat lights no battery

Poor OP, every other post discredits the previous. Use your battery charger. As Silvertips stated, the devices are only going to draw what they need, and we are only talking about your lamps and probably a bilge pump.

I am sure we have people who want you to do and begin to do things in an orderly, proper fashion. Why start off with an improper testing procedure? But for a brief test of your lights, go ahead. However, if feeding gps, radios, motor electronics, it is probably agood idea to do things properly, and that is with a battery in the circuit.
 

mthieme

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Re: boat lights no battery

I'm not usually anal about such testing procedures.
Heaven knows, all to often I have chosen the path of least resistance.
I concede via an Alfred Plea.
 

ebry710

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Jan 29, 2008
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Re: boat lights no battery

By the time we debate battery vs the charger you can go down to Interstate and buy a battery.
 

mthieme

Captain
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Re: boat lights no battery

Amen.
$30 and a trip to wally world.
Done
 

achris

More fish than mountain goat
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May 19, 2004
Messages
27,468
Re: boat lights no battery

Electronic engineer here....

DON'T USE A BATTERY CHARGER WITHOUT A BATTERY CONNECTED!!

Chris.......
 

Silvertip

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Sep 22, 2003
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28,762
Re: boat lights no battery

OK Chris -- Explain why it can't be used to test lights. Remember -- we are not testing sensitive electronics. Everyone knows, or should know, filtering is not very good on many auto/marine chargers so I will agree they should not be used to power sensitive electronics without a battery to absorb ripple and noise. Anyway, to prove my point, here is a 6 amp charger connected directly to a 7 watt, 12V landscape bulb. Your an engineer so you can do the math to determine current draw but you will note the ammeter has not left the zero peg. The charger was connected for about five minutes while I rounded up my camera.

Charger.jpg
 
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