Your Garmin will tell you voltage when you are on the dashboard screen, (you may have to put voltage on the selections) so you can monitor it. If your batteries are fully charged and healthy my 31 group will last a couple of days.
, there are lots of variables. This question has been asked a lot so do a search and you will find more.

 

Thanks, Mike. Nice to hear from you again!

The Garmin is only interfaced with the marine radio so I can't see the draw. The batteries are only 5 months old and we only need to run it for 2 days....

I'll search the forums more.

Rocco

 

Rocco. If your Garmin has power it will tell you how much power is available to it, no special connections needed. Mine has about a 1/4-1/2 volt drop in display voltage vs what a meter indicates directly on the batteries. MM

It took me some work to find this feature on mine.

 

Did you look for this? MM

 

:huh:I am rafting up this weekend and will have my small mini-fridge that came with the boat running.

How long will it run off the battery before I need to start the engine to recharge?

How often should I run the fridge?

How often to run and for how long to recharge that battery?

Thanks!

:huh:

There are so many variables an answer is almost impossible to give you.
What is the amperage of your house bank, the voltage is the same in every battery but the amperage will be different.
I have 2 golf cart batteries 225 amp hours but you can only run them down 50% of the capacity so I have 112 amp hrs to run the boat.
My fridge draws 3.5 amps and with the lights and the radio and the electric head we draw about 7-9 amps per hour so I get about 18 hours out of my system.
If you drain down your batteries 100 amp hours it will take 3 to 4 hours to recharge the next day.
It does get a little complicated being on the hook, your batteries are the most important thing to watch.
I have a link 1000 and a Xantrex 1000 inverter charger the link is like a fuel gauge but for batteries.

Ken

 

I cannot answer how long they will last, as was pointed out, there are too many variables. I can tell you a few leasons that I have learned. When the batteries get old, they drop off very quickly. Our house bank did just that after being on the hook for about 24 hours. I went to check the volts and found the gauge below 8v. Fortunately, I turn the starting battery off when we are in on the hook. We do not have a generator. I was able to start the left engine. I than used the emergency start switch to close that relay and tie all the batteries together. I than used the left engine to charge the right house bank. Which coincidentally startes the right engine. So I stood there for about 20 minutes holding that switch to get some power into the house bank and than started the right engine. All was normal after that.

Needless to say, I am off to get some new house batteries.

 

I'm having battery woe's myself. In the course of troubleshooting, my fridge uses just under 5.0 amps when on. I put the fridge to max when I have shore power to cool it off. and drop it to mid setting when out and about. In theory... my battery is rated at 200 minutes @ 20 amps. so 1/2 is 200 min at 10 amps. Which in theory would give the fridge 400 min of use time (actually in the cooling phase)

As a side note.. i discovered that EACH light (bulb 1141) uses 1.45 amps. The single LED test bulb I bought uses 0.20 (ish)

I too fear I am going to need to buy new batteries before the start of next season.

 

Mike,

I ended up in an 11 boat raft-up next to a 40' Ocean Yacht with a huge generator and was plugged into him most of the time so the issue became null.

I never got a chance to play with the Garmin settings but I plan to poke around them this weekend as I will be overnighting with one of my kids Friday night.

-Rocco-

 

If you need more help to find it, I will be with the boat this weekend. MM

 

Thanks, Mike. Will bring a laptop with internet wifi in case I need to reach out!

 

Thanks Mike,


I didn't know I could get battery info on my Garmin 545s, I just look at the manual and noticed the Battery alarm under Config>Alarms>System

Rocco check out page 46

http://static.garmincdn.com/pumac/GPSMAP_400_500_Series_US_OM.pdf

 

I'm not talking alarm, but a digital readout on what Garmin calls the "dashboard". I keep that screen up all the time except when under way. You can choose to display 3,4,5, or 6 data fields on the "dashboard" display depending on how large you want the text size. I never saw this in the sorry excuse for a manual. MM

 

We lessen the drain on our batteries by keeping 2 of those blue freeze packs in the freezer when not using the boat.Then move them down to the lower refrigerator part when we are on the hook.Also we keep very little beverage in the refrigerator , its kept in the ice cooler.This lessens the refridge door getting opened and closed.