Another electrical question

bestfriend · #1 (**permalink**) 07-04-2007

I am onboard reading posts about electronics, trying to decide if I should run everything off a computer, including LCD monitors inside and out and TV through the computer. All of a sudden I realize that the lights are getting dim, and that its not the amount of alcohol I've had. So, I start to think that the power draw may be way too great to run a computer on board, if I am draining the batteries to keep this thing charged. Then I start to think, I am on shore power, shouldn't the batteries be a non-issue? I have one start battery and two house batteries. I keep the switch on one and I have a charger on a timer. I turned the charger on and its all back up to snuff, but what is the issue here, is my shore power inadequate, do I have the switches wrong, do I need the charger on longer, do I need to stop worrying and have another drink?

PBzeer · #2 (**permalink**) 07-04-2007

If you're on shore power, why aren't you running the computer off of the 110v? As to the draw on the batteries, how are you powering it when on battery power? Large, hardwired inverter? Plug-in portable inverter?

My laptop draws 4-5 amps through a 400 watt portable inverter. About the same as the reefer. Not sure how much draw a dedicated chartplotter would have, so can't comment on if that would be a more efficent use of power. Personally though, I like using the chart software on the laptop, as it has a 17" widescreen, making it easy to magnify in dicy areas.

Currently at 35 54 33 N 75 40 06 W

SimonV · #3 (**permalink**) 07-04-2007

BF
If your battery charger is only 4 or 8 amps supplying a trickle charge to the battery. your inverter is hunting for power and can only get it from the battery and your charger is unable ot keep up with the power drain. A 400 watt inverter will draw 33.3 Amps.

sailingdog · #4 (**permalink**) 07-04-2007

Another point, if you're using a fairly small charger, which it sounds like is the case, you don't want it on a timer, since it will never get a chance to fully replenish the batteries that way. While the bulk charging phase of the batteries (up to 80% or so) goes rather quickly, the 80-->100% phase takes quite a while, as the charge acceptance rate of the batteries drops dramatically once it hits 80% charge or so.

PassionKid · #5 (**permalink**) 07-04-2007

BTW PBzeer - wave - I think I see you on Google Earth

Enjoy Manteo! Wish I was there rather then work!

bestfriend · #6 (**permalink**) 07-04-2007

Some more info for you guys. I am running the laptop off the 110v. The charger is a small 8 amp trickle. No inverter. The PO never stayed on board, so the trickle worked well for him. I need to improve this set up as I will be spending much more time aboard. Any suggestions? Get an Inverter? I guess I should start charging the batteries for 24 hours at a time. If I have the Perko selector on, and am on shore power, am I drawing anything from the batteries? Should I just turn it to off until I am charging? Thanks for the help. First night went well, too much celebrating. The dog caught a mouse, not on board.

sailingdog · #7 (**permalink**) 07-04-2007

If you are on shore power, with the trickle charger plugged in a running, leave the battery bank switch off. Having it on will introduce small loads and tempt you into turning something and then you'll probably be using almost as much electricity as the trickle charger provides. If you have wet cells, don't forget to check the electrolyte levels and add distilled water as needed.

Sailormann · #8 (**permalink**) 07-05-2007

CS built a lot of its boats with Converters rather than Inverters. If you have original equipment, you may have one of those... I have three batteries on the 30 as well, and find that I have to keep my battery switch on "All" to keep everything up and running at full power, when we are plugged in. When we're just on batteries, it's not an issue.

When you are alongside you should be able to plug everything into the shorepower...

bestfriend · #9 (**permalink**) 07-05-2007

Everything seems to be running good today. No electrical drain. This is such an old marina, I wonder if they have power draw problems sometimes. I turned the perko off and ran the charger all day. I noticed that the bilge filled up (ice box full with beer and ice) and it does not run with the perko switch off. Seems a little odd. I am not sure about the converter. How does that work and where would it be, behind the panel or inline somewhere?

CapnHand · #10 (**permalink**) 07-05-2007

Your boat is haunted. Good news is the spirits seem to be playful, not mean. Having the ice box full of beer seems to keep them at peace.