House battery short life

[Wassim Merhebi]

I own a 2023 SDX 290 with twin outboards .
When I first got delivery from new I asked the dealer to install an extra battery (total 3 ) with a separate power switch to use for accessories while out at sea .
When we are out I switch off both engine battery switches and keep the house battery on to use for music system and lights mostly .
After 1 year of use , average use is two outings per month , the battery lost most of its power , it’s giving 10v now so not possible to operate the music system .
The dealer said the battery is almost dead and needs to be replaced .
When the boat is docked I connect it to shore power to charge all 3 batteries and keep it connected .
I’m concerned that I will have to change the house battery every year unless I find a solution.
Has anyone come across such a situation and what can you recommend?
My 2nd question , is it recommended to keep the shore power connected all the time when in the marina ?
I have owned a number of boats and always used the same protocol but I never faced the issue of depleted battery in such a short time .
Look forward to read your recommendations with thanks .

 

[Creekwood]

It sounds like that house bank is not properly connected to the charger. Test the voltage right at the house batteries when the charger is turned on. It should read the charger voltage, which would be about 14 volts or more.

Yes you should leave your chargers turned on all the time when connected to shore power. Modern chargers will not damage the batteries. It will also protect the boat in case you develop a leak and your bilge pumps have to run run.

 

[ranger58sb]

When we are out I switch off both engine battery switches and keep the house battery on to use for music system and lights mostly .
After 1 year of use , average use is two outings per month , the battery lost most of its power , it’s giving 10v now so not possible to operate the music system .
The dealer said the battery is almost dead and needs to be replaced .
When the boat is docked I connect it to shore power to charge all 3 batteries and keep it connected .

Have you checked the house battery voltage before leaving the dock?

Is the house battery connected to any kind of charging source while you're away from the marina? Engine alternator?

Is it a flooded battery, and if so have you routinely replenished the water supply?

"Lights" suggests overnight use -- is that without charging? An incandescent anchor light or deck lights can be a big draw; LEDs could significantly reduce that.

And/or is your music system so huge that you also entertain everyone else on the water?

-Chris

 

[Lazy Daze]

What type of battery is it? Brand/group/style?

 

[Wassim Merhebi]

Have you checked the house battery voltage before leaving the dock?

Is the house battery connected to any kind of charging source while you're away from the marina? Engine alternator?

Is it a flooded battery, and if so have you routinely replenished the water supply?

"Lights" suggests overnight use -- is that without charging? An incandescent anchor light or deck lights can be a big draw; LEDs could significantly reduce that.

And/or is your music system so huge that you also entertain everyone else on the water?

-Chris

Hey ,
Thanks for getting back .
I haven’t checked before leaving the dock , I will do so with the new battery. I assume you asked this question to make sure that the house battery is getting charged from shore power ?
The battery is connected to the engine alternator.
It is a flooded battery but I never checked the water level since I never had to do that with my previous boats and the batteries survived just fine but never more than 3 years .
We don’t stay out overnight , generally around 8 hours . Music is on most of the day , LED deck lights for half of that so is the anchor light.
I have a decent music system with amplifier and tower speakers but not the type that is obnoxious to annoy all other boaters .

 

[Wassim Merhebi]

It sounds like that house bank is not properly connected to the charger. Test the voltage right at the house batteries when the charger is turned on. It should read the charger voltage, which would be about 14 volts or more.

Yes you should leave your chargers turned on all the time when connected to shore power. Modern chargers will not damage the batteries. It will also protect the boat in case you develop a leak and your bilge pumps have to run run.

Thanks will check the voltage as suggested.

 

[searay495]

Hi, I have a similar question. I know what the quick short answer probably is, but hoping someone with electrical knowledge will chime in. I have 4 Group 31 AGM batteries connected in series. They were purchased in 2019. I have had no electrical issues, starting, etc. Out of boredom I disconnected each battery and performed a load test. One failed. Do I need to replace all 4 batteries or is the passing of a load test on the other 3 batteries sufficient to hold on to them? Thanks in advance.

 

[Creekwood]

Hi, I have a similar question. I know what the quick short answer probably is, but hoping someone with electrical knowledge will chime in. I have 4 Group 31 AGM batteries connected in series. They were purchased in 2019. I have had no electrical issues, starting, etc. Out of boredom I disconnected each battery and performed a load test. One failed. Do I need to replace all 4 batteries or is the passing of a load test on the other 3 batteries sufficient to hold on to them? Thanks in advance.

It’s always better to replace all of them at the same time so you know a bad one won’t cause overcharging on the others. You may be able to get away with just one being new, but the others may cause that new one to fail earlier.
By the way, your four batteries are probably wired in parallel if its a 12v bank, or maybe two in parallel sets of two that are then connected in series to make a 24v bank.

 

[ranger58sb]

I haven’t checked before leaving the dock , I will do so with the new battery. I assume you asked this question to make sure that the house battery is getting charged from shore power ?
The battery is connected to the engine alternator.
It is a flooded battery but I never checked the water level since I never had to do that with my previous boats and the batteries survived just fine but never more than 3 years .

Is it a flooded (wet) battery? Or flooded but sealed "maintenance free"? Or AGM?

Might or might not be the same kind of batteries you've had in the past...

-Chris

 

[searay495]

It’s always better to replace all of them at the same time so you know a bad one won’t cause overcharging on the others. You may be able to get away with just one being new, but the others may cause that new one to fail earlier.
By the way, your four batteries are probably wired in parallel if its a 12v bank, or maybe two in parallel sets of two that are then connected in series to make a 24v bank.

They may be!! I need to take a closer look at that. If they are set up the way you suggested, do you still feel I should replace all 4?

 

[ranger58sb]

If they are set up the way you suggested, do you still feel I should replace all 4?

They will be. Four 12VDC batteries wired in series would be a 48VDC bank... and you don't have that. Four 12VDC batteries wired in parallel gives you a 12VDC bank, more likely what you have.

Replacement depends... but generally yes.

The "depends" part is about age and remaining capacity. You could do a voltage test and a load test... but generally batteries that retain a 12.6VDC resting voltage (i.e., after being off the charger for at least 4 and maybe up to 24 hours) might still be OK.

Otherwise usually assume all batteries in a given bank would be best replaced all at the same time.

-Chris

 

[Evidence]

I own a 2023 SDX 290 with twin outboards .
When I first got delivery from new I asked the dealer to install an extra battery (total 3 ) with a separate power switch to use for accessories while out at sea .
When we are out I switch off both engine battery switches and keep the house battery on to use for music system and lights mostly .
After 1 year of use , average use is two outings per month , the battery lost most of its power , it’s giving 10v now so not possible to operate the music system .
The dealer said the battery is almost dead and needs to be replaced .
When the boat is docked I connect it to shore power to charge all 3 batteries and keep it connected .
I’m concerned that I will have to change the house battery every year unless I find a solution.
Has anyone come across such a situation and what can you recommend?
My 2nd question , is it recommended to keep the shore power connected all the time when in the marina ?
I have owned a number of boats and always used the same protocol but I never faced the issue of depleted battery in such a short time .
Look forward to read your recommendations with thanks .