How long will a battery hold charge prior to using it?

[FreddyTT]

I park my boat in a storage lot. There is no power in uncovered parking, so I used to pull the batteries out every week and bring them home during boating season. Total pain! Last year I picked up a Honda 1000 generator and l chain it to my trailer to charge the batteries. Made life easier for sure. This year I picked up a Pro Sport 20 amp dual bank charger. So far, I love it. Its supposed to charge both batteries independently and has a sensor that allocates the rest of the power to the deep cycle when the cranker is charged. I think this charger is going to save me trips to the storage unit to fill the generator with gas and hopefully save me even more time overall regarding my batteries based upon my situation.

I was wondering how long the batteries would hold a full charge as long as the battery switch is off? Since I take it out on Saturdays, I am often busy with work, laundry, dinner etc all week and approaching Saturday, Im getting food for the cooler and I wash the boat and spot vac it the night before I take it out. It would be nice if I could get the battery charging out of the way Monday, or Tuesday so I can move on to other stuff during the week. Is it possible the batteries would lose charge if not on a battery tender with-in 7 days once fully charged with the switch off? Or do I have to charge them with in a day or two of taking it out?

 

[ondarvr]

You only have several months with good batteries, sometimes much longer.

 

[Chryslerman123]

You should have no problem with dead batteries if only sitting for a week. I keep my boat batteries in my closet all winter from late November to mid April. I don't even have to charge them. I just put them in in spring and they always crank the motor just fine.

 

[bruceb58]

Flooded lead acid batteries self discharge around 1% per week.

 

[roscoe]

You should't need to charge your starting battery at all.

Deep cycle after each use.

So, you hook up the charger, start the generator, and sit there at the storage lot for hours while it charges?

What is the deep cycle used for? trolling motor? stereo? does it get depleted each day on the water?

Might be easier, more convenient, less time consuming, to charge the deep cycle at home, or while towing back to the storage lot.
It should only take you a minute to pop the battery in/out.

 

[fhhuber]

Depends what is hooked up.

If the battery is maintaining a stereo's presets memory, you have about 3 months.

If its maintaining all the memories in a modern car, 2 to 3 weeks.

Terminals disconnected, 6 months to a year.

 

[mr 88]

The Honda generator is small and lightweight along with a run time of about 8 hours and has a 10 amp built in battery charger. Why not fill it up,lock it in the boat and never worry about your batteries going dead while on the water. Do that with my duck hunting boat that is used in the dead of winter with temps of 0-20degrees. Peace of mind on the upper Niagara River,the falls is a big drop........

 

[Ned L]

What everyone else said,.... and a little more perspective;.... You park your car in the garage,..do you expect a dead battery in a week or two?

 

[Old Ironmaker]

There was a very similar thread last year. The problem was the deep cells needing a charge after every use. I believe the solution was solar panels. The cranking battery will be fine. Mine goes untouched for over a month at times in warmer weather. A booster pack on board is always a smart thing to have for the cranking battery. Small and cost less than 100 bucks. I have used it more than a few times to give other boaters a boost.

 

[BRICH1260]

I think you`d be better off to just bring the batteries home and keep them there until you bring the boat home in the spring, rather than running them back and forth. Sooner or later somebody is going to take your new generator. Plus you can keep the batteries in more of a climate controlled environment.

 

[BigDfromTN]

Maybe hook the Honda up when you trailer your boat and charge the deep cycle on way to storage lot. Depending on time to lot you may be ok. Could also then fire up Honda for ride back to ramp if needed. I would not want to leave a $1000.00 generator ( or there about) unattended!
Like others say, crank g battery should be fine.