Depthfinder/Chartplotter battery drain?

[Kevin C 26S]

Hi all,I'm still looking at getting a depthfinder/chartplotter combo, but have become concerned regarding the potential power usage of these guys.It seems the fishfinders are all about higher power output. RMS of 200W with some as high as 1000W. Seems like this would drain my batteries pretty darn fast. Since I plan to sail as much as possible (vs. motoring) I would think a few hours (or less) of usage would be enough to kill my battery. Not good for a long weekend out on a new lake.I know with some speakers I've seen they have these rediculusly high 500W ratings, but I can tell they aren't drawing that kind of power based on the wimpy little wires going to them.Any of you with one of these guys know if these power outputs are real? Or if the battery drain is a big deal?

 

[Joe A]

Depth finder power is pulsed

The transducer power is pulsed with a very short duty cycle. I don't know the actual power usage, but it's not as much as you think. I left mine on the other night and I didn't even notice the drain.

 

[Robspan]

Depthsounder

I have a monochrome depthsounder that I once left on for two days. It had no noticeable effect on the battery. I checked it with a hydrometer back at the dock and the battery was still high. I don't know how much more a color display and/or a chartplotter would add but I doubt the transducer will be a problem.

 

[Kevin C 26S]

Thanks!

Thanks.Didn't think about the "pulsing" possibility. That helps a lot!Thanks again!

 

[Kevin C 26S]

Bit the bullet...

Well I ended up going with a GARMIN GPSMAP 498C. Just under $500 w/ shipping on EBay. Color, built in detailed coastal maps.More than I really wanted to pay, but I'm pretty sure I will be happy with it.Thanks for the advice again.

 

[Kevin C 26S]

14 watts

So while reading my manual, I found that it used 14 watts max, no where near the 500 watt rms that the sounder puts out.14 watts is not neg. but I should be able to deal with it if I add a second battery.

 

[walt]

battery might be ok..

If your battery is around 12.5 volts, 14 watts "max" is about 1 amp current draw (the equation is simple: watts = amps * voltage ). If you used the chartplotter for 20 hours straight, you would have consumed 20 amp-hours. Compare this to your single battery which probably has a capacity of 80 to 125 amp hours. The 20 amp hours (for 20 hours of use) might only be about 1/5 of the battery capacity. You generally dont want to take a battery below 1/2 of its capacity but if the chartpotter is your only major power drain and your not going on extended trips without a method to recharge the battery (ie, with solar or using the motor alternator), you might be OK as is. Looks like a cool instrument..

 

[Kevin C 26S]

Yeah I did some research...

I did some research right after that post, and realized I would probably be ok (100 amp hours and what not). I also have a small 5W solar panel, and the outboard has an alternator on it. So they should help too.The other drains would be the anchor light and interior lights. I've decided to go with a "boom box" for music to avoid the battery drain.Thanks again for the advice.