Battery questions

[townvet]

At the risk of demonstrating my ignorance...

If my boat is plugged into shore power and the battery charger is on...is it ok to keep the batteries running for extended periods such as running both live wells overnight? Keeping the spreader lights on for many hours?

How long with the engines off and the boat not plugged in will the live wells keep going without sacrificing battery life? Can we fish for hours at anchor or drift with the batteries powering things and engines off? [/code]

 

[grady23]

Answer #1 -- Probably all night if your boat is equipped with an onboard charger.
Answer #2 -- Depends on how good your batteries are and how hot or cold it gets. Normal summer usage, I would think 3-4 hours without the engines running, but that just an un-educated guess since I've never tried it for any longer than that. I have dual batteries and start and run them in the "Both" position.
FYI -- Unless your boat is equipped with the type of battery switches that allow you to switch while the engine(s) are running, don't throw the switch while running the engines. You run the high risk of blowing the alternator(s) by doing it. The normal "GUEST" brand switches don't allow you to do the switch while running.

 

[wahoo33417]

Town Vet: I have run my live well for up to three hours with no obvious affect on the battery. I have a pair of AGM's. I run out on one battery and then run the livewell on the other. That way, if I did manage to run down the second battery, I know I have the first battery, that I ran out with, in good shape.

 

[JiminGA]

I have dual batteries and start and run them in the "Both" position.

Just a note of caution for you, Grady23: Starting and running on BOTH can potentially mask one of your batteries going bad. You may want to consider alternating between 1 and 2. For instance, if we are boating all day, I'll run on one battery in the morning and the other in the afternoon. Or 1 on a "Trip Out" and the other on the "Trip Home" - you get the idea.

In fact, this method identified a bad battery on our Grady just a couple of months ago. Because of their age (4 years +), I went ahead and replaced both.

PS A final note - starting and running on just one battery gives you an "emergency option" of switching to BOTH to get the engine started if all else fails and you are in a situation where you NEED to get it started!