Christmas Lights and Battery Power

[r.oril]

I plan to put my Mac 26D in a lighted boat parade for the first time this year. I have 2 RV type batteries and a 10 year old 400 watt inverter. The LED lights will have to be on for about 2-3 hours. During the parade the Honda OB will be running and puts out 13+ volts.
I want to run lights up all rigging and around the life lines with a lighted raindeer on the bow.
Not having done this before, what problems might I incure?
I know we have a few electric wizzards in our group and someone "has been there done that".

Thanks

 

[Rick D]

If They Are LED's,

...you won't have a problem. Regular mini lights pull about ten amps (converted to 12 volts)/ hour for 200 which is about 80 feet. There is some inverter loss, but if you start out with a full battery, you are good. LED's are a lot less draw. Have fun!

 

[r.oril]

...you won't have a problem. Regular mini lights pull about ten amps (converted to 12 volts)/ hour for 200 which is about 80 feet. There is some inverter loss, but if you start out with a full battery, you are good. LED's are a lot less draw. Have fun!

Rick D - Thanks for the reply/info.
Bob

 

[txtowman]

I concur

 

[walt]

Yup, no problem at all. In the picture below, there is an LED anchor light on which draws about 300 ma directly from 12 volt and also a couple strings of 120 VAC LED Christmas lights (maybe just under 20 foot) run off a 175 watt inverter. The total current draw from the 12 volt battery for all of this was just a hair under 1 amp. So the LED string (and fairly inefficient inverter) used maybe 0.7 amps at 12 volts. The string in the picture looks like maybe 20 foot so you could assume a current draw on the batteries of maybe .035 amps per foot. Ie, I think you can really light up the boat with LED Christmas lights and not stress your battery much at all. Have fun.. I think I may know where you intend to use this?

 

[Benny17441]

Just watch your connections. Allow me to suggest that you place your inverter as close as to the batteries as possible and that you hard wire it to the batteries instead of using a 12V plug. This will insure a solid connection and will allow you to use the maximum output of your inverter. Install a fuse on the positive lead and make sure you do not cross the leads. A 400W inverter at maximum output will draw about 3.5 amp/hour so your two batteries should be more than adequate for the desired time. You can use regular mini lights and run extension cords between lights and inverter as necessary. Another suggestion is to divide your lights into two circuits. Your inverter should have two 120V oulets so you could plug one circuit into each. What this will do is to allow you to shut down half of the lights in navigation streches where they may not be needed and then turn them on for full effect where crowds of observers may be gathered. You may artistically arrange each circuit so that each looks good on its own. A music boom box can be used to play X-Mas music. We participated for 3 years in a row in the FT. Lauderdale Light Parade and ran around 5,000 lights and a big stereo amplifier and speakers with a portable generator. It helps to pick a theme and try to work it into a lights design as well as dressing up for the part. You will enjoy it and the crowd will appreciate your effort.

 

[r.oril]

Cool picture Walt. Any more photos of decorated boats? I could use the ideas. Two separate lines for sure.
Again, thanks to all for your valued input.

 

[druid]

Incandescent Christmas lights are SO 80's! Go LED, you'll never turn back. And when you do, you'll have no problem lighting up the whole boat for an evening on a battery and invertor (We once were in a parade where we had a 15ft long dragon lit up by strings of Christmas lights, with a guy at the back pushing a small grocery cart with a battery and invertor.)

druid

 

[walt]

r,oril, we have the same boat (and I have AC powered LED Chrismas lights on also) so I thought I would pass on one more thing.

It regards the safety issue of using 110 VAC Christmas LED lights and the very unlikely risk of having the powered lights fall into the water with a swimmer near by. What would happen probably depends on salt content of the water, how close the swimmer is, etc - but it could be dangerous. And I would agree that the risks of this ever happening are extremely small (ie, don't let anyone swim near the boat when the lights are on).

Regardless, GFI outlets are a good way to protect for this problem. Pretty simple - just use a GFI AC socket coming off your inverter that power's the Christmas lights. Ie, take the AC out of the inverter and run it to a GFI socket. Plug the Christmas lights into the GFI socket.

The slightly tricky thing with this is making sure that the Green ground on the GFI outlet gets to the water. GFI only trips when some of the "hot" AC current flows to the green ground. If the light string falls in the water, it would trip the GFI only if the GFI ground is also in the water.

On the setup I just did, I used a "hardware store" inexpensive inverter to power the LED Christmas lights. On this particular inverter, the AC green ground is internally connected to the 12 volt DC ground. Since my DC ground is connected to the outboard, all I need to do for the safety issue is make sure my outboard is in the water.

A second small inverter I checked did NOT have the AC and DC grounds internally connected - so you should check this (just use an ohm meter between the grounds unpowered. In this case, you would have to make sure the GFI socket ground was somehow connected to the outboard.

As mentioned.. risk of any problem is probably extremely small - but thought Id post this just in case..

 

[arghhh]

GFI only trips when some of the "hot" AC current flows to the green ground.

Not quite. A GFCI monitors the amount of current flowing from hot to neutral. If there is any imbalance, it trips the circuit. It is able to sense a mismatch as small as 4 or 5 milliamps, and it can react as quickly as one-thirtieth of a second.

Some of the newer inverters use GFCI outlets on them and is never a bad idea.

 

[walt]

what I said is correct. And what you said is also correct. Ill clarify a little more..

All current flow normally should be between Hot and Neutral. GFI is monitoring current between hot and neutral and expects them to be the same. As you probably know, in the US, the Neutral is normally "about" the same voltage as ground.

So how do you get the imbalance in current between hot and neutral to trip the GFI? Hot to green is 110 VAC, Neutral to green is about 0 VAC. If I put a powered light string in the water, there is a big voltage potential between hot to green but not neutral to green. So current flowing from the hot to green (ground) causes the imbalance between hot to neutral and is what trips the GFI (what I originally said).