Batteries not holding charge

[Ahoy Polloi]

New to this site and power boating. Just bought a 2006 sundancer 300 and I think I mucked up my batteries some how. Boat was running fine and then we hooked up to shore power overnight and didn’t switch the shore power switch to on and never turned on the AC convertor switch to charge the batteries. The next morning there was a weird alarm sound in cabin and my port engine would not start. We plugged into shore power again and made sure all switches were turned on to charge battery. It looked as though the battery charged (although not fully) and I felt confident that my port engine should start. That was not the case. I was able to eventually get the port engine to start - only because the throttle had to be jiggled to make sure it was truly in neutral. The throttle is a separate issue and probably needs to be replaced. After taking boat out to mooring and trying to start a cpl of days later, nothing. No power whatsoever. Generator will not fire up and the AC volt meter shows a weak battery. Any thoughts on what is going on? Going to have a mechanic take a look but if it’s batteries at end of life, I figured trying yo replace them myself.

 

[CaptRonn]

How old are the batteries?

Sounds like they are shot.

 

[Ahoy Polloi]

How old are the batteries?

Sounds like they are shot.

Thx for the reply. I really don’t know. Trying yo contact previous owner to find out. I think they must be. We did put abt 8 hrs on the boat before having the problem and the problem started after we hooked up to shore power which is why i’m wondering if I overloaded smtg.

 

[CaptRonn]

More than likely you have old batteries.

Start by replacing them. Then check your battery charger to make sure they are charging correctly.

 

[CaptRonn]

Your throttle safety switch sounds a little sticky. Try a little lube, or replace it. Easy replacement and not expensive.

 

[Timeflys]

If your batteries are lead acid, how are the electrolyte levels?

 

[Espos4]

Sound like you ran off battery power while at the dock and not having the shore power properly switched on.

A deep discharge is the kiss of death to an older battery. If it was marginal before, that deep discharge probably killed them.

If you plan on keeping this boat for a few years, you will replace the batteries at some point. With the unknown age and problems you are having, replace them all now and enjoy the benefits.

 

[yobub]

You can buy a battery load tester from Amazin or somewhere else. It will put a load on your battery the way a starting draw will, and tell you the condition of the battery. I would recommend this as a first step before anything else.

While I agree that bad batteries is the most likely issue, start by understanding what is really wrong. You may have a bad ground or some other issue.

You can also pull your batteries out and take them somewhere to be tested, but a load tester saves you the hassle.

 

[R-and-R]

Like many have said, it’s likely batteries are shot.
But start with something easy...clean the terminal connectors. It’s what I tell all my friends whenever their car batteries get finicky.

 

[Ahoy Polloi]

Thanks to everyone for all feedback. Going to check the connections snd test the batteries with the load tester. If replacing all 4, does anyone have brand recommendations? Sealed vs not sealed? Low maintenance, etc?

 

[RBB]

Thanks to everyone for all feedback. Going to check the connections snd test the batteries with the load tester. If replacing all 4, does anyone have brand recommendations? Sealed vs not sealed? Low maintenance, etc?

AGM battery's

 

[Pirate Lady]

Your batteries are junk, buy new. When your flashlight don’t work do you try figure out what wrong with the flashlight? Just replace the batts.

 

[yobub]

Thanks to everyone for all feedback. Going to check the connections snd test the batteries with the load tester. If replacing all 4, does anyone have brand recommendations? Sealed vs not sealed? Low maintenance, etc?

There have been many battery threads that discuss the benefits of AGM vs traditional, so you might research those to quickly get an in-depth perspective. Before you buy AGM batteries, make sure your charger will support AGM. Different people have different brand preferences, but there is some consensus about price and quality from the Sams Club batteries. Again, there have been many discussions here about brands and preferences.

 

[Ahoy Polloi]

So I got a shot of current battery setup. Boat is dead in the water. Could barely get the deck to lift for access to engine compartment. Based on this photo, any suggestions on replacements? Looking at 4 79 Amp AGM’s. Is that enough power for this 30’ cabin cruiser?

 

[ttmott]

Not much worse than batteries that can't be trusted in a boat. Probably smart to baseline your boat with new batteries. I would reinstall with Group 27 dual purpose batteries which are around 90 amp hours each. Yours looks to be Group 27. Group 31 dual purpose at 100 amp hours are another good choice if they will fit. AGM batteries have a lot of benefits but as others have said it is best to have a charger that can efficiently maintain them, not mandatory however. AGM charge profiles are slightly different than flooded lead acid batteries.
As a point of information that may help, your battery charger / converter is independent of the battery switches; in other words the charger/converter will supply power to the batteries regardless of the battery switch configuration. That is, as long as it is getting AC power.....

 

[Ahoy Polloi]

Thx so much for the feedback. There is a 30 day wait to get the batteries you mentioned from West Marine. Amazon seems to have more batteries ready to ship. Any knowledge of this brand? Want to stay away from anything dicey.

Banshee BCI Group 27M Dual Purpose Deep Cycle Sealed AGM Marine & RV Battery https://www.amazon.com/dp/B088X5YP3H/ref=cm_sw_r_cp_api_glt_fabc_FAJ706GC9P55JMSNFBBT

 

[CaptRonn]

Thx so much for the feedback. There is a 30 day wait to get the batteries you mentioned from West Marine. Amazon seems to have more batteries ready to ship. Any knowledge of this brand? Want to stay away from anything dicey.

Banshee BCI Group 27M Dual Purpose Deep Cycle Sealed AGM Marine & RV Battery https://www.amazon.com/dp/B088X5YP3H/ref=cm_sw_r_cp_api_glt_fabc_FAJ706GC9P55JMSNFBBT

Any auto parts store sells batteries, and not at boat boutique prices.

Bought my last batteries at Autozone, about $100/each. (lead acid)

 

[brewster16]

Thx so much for the feedback. There is a 30 day wait to get the batteries you mentioned from West Marine. Amazon seems to have more batteries ready to ship. Any knowledge of this brand? Want to stay away from anything dicey.

Banshee BCI Group 27M Dual Purpose Deep Cycle Sealed AGM Marine & RV Battery https://www.amazon.com/dp/B088X5YP3H/ref=cm_sw_r_cp_api_glt_fabc_FAJ706GC9P55JMSNFBBT

The following statement might be controversial and is my opinion only: As a brand new boater don't get sucked in to the notion that West Marine should be your source for everything. I can remember when I got my first boat..... I excitedly went to West Marine for everything, joyfully getting ripped off because I was a "boater" in a boat superstore! After overpaying for so many items I eventually realized they are 30% more expensive than everyone else for practically everything!

 

[ttmott]

Batteries-plus and Walmart are also good sources. Maybe just me but I try to stick with the name brands.
Remember with mail order batteries you have to pay return freight for a warrantee claim.... That is the main reason I don't mail order these types of weighty consumables.