Permanently Charged or Let Them Idle?

I am a new owner of older boat (2 months). I keep it at the dock with shore power provided. The house batteries - 6 golf cart batteries - were almost dead so I had brand new installed. Starting batteries are OK. There is Xantrex inverter/charger, generator and all usual equipment.

After each use I fully charge all the batteries and then boat waits for another trip; few days, a week or maybe two (never longer so far).

Should I keep the batteries permanently on charge (floating charge I understand) or, once fully charged, I should let them idle while waiting for another trip?

If one way is better then the other then why?

Thank you.

What charges the the various batteries and banks. The Xantrex? if so odds are extremely good you can just leave it on. Only some really old fashioned (and not all of them) ferroresonant chargers should be turned off.

What he said.

Yes, I would not expect that a permanent charge would cause any obvious damage. But after letting fully charged battery sit idle for say two weeks I find it keeps a full charge perfectly.


So, both ways do not cause any obvious harm. But again, being perfectionist, I keep asking myself what should be my routine? Is there any, no matter how small, advantage or disadvantage to any of these methods?

If your bilge pump has reason to run during two weeks away, you'll be glad you left the charger on full time. Modern chargers are designed to be left on.

hmason said:

If your bilge pump has reason to run during two weeks away, you'll be glad you left the charger on full time. Modern chargers are designed to be left on.

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I agree.. I personally would not leave my boats off the chargers for more than a couple of days.
Leaks and pumps have a habit of killing batteries

Many chargers can have the float voltage owner set.

There is no problem with overcharging and running out of water on charge if the V is set at say 13.4 or so.

The many folks that use solar have a 100% charge almost daily and become concerned of water use.

Having the charger on is insurance against a leak that could sink the boat.

In a marina some folks will rig an alarm that sounds each time the bilge pump operates., when the boat is unoccupied.

We been a live aboard for 18 years and the boat is always on charge. Over the years seen boats sink and water damage because the battery was dead. Also do not leave the boat withthe ddomestic water left on, and close sea cocks below the water line. I fill the water tanks and use the boats water pump, and when at dock all the sea cocks below the water line are closed for peace of mind.

We usually leave her connected to shore power. Reasons given above. Battery charger will change to conservation mode if batteries are fully loaded. Our charger has in addition a temperature sensor to avoid "boiling" the batteries.


best regards / med venlig hilsen
wadden

"when at dock all the sea cocks below the water line are closed for peace of mind"

This is nice if you have cable operated sea cocks ,

or dont leave the dock but every few months , but for most a PIA.

I would leave the engine operating key on a closed engine intake valve.

Peace of mind comes from having regularly inspected and maintained plumbing.

FF said:

In a marina some folks will rig an alarm that sounds each time the bilge pump operates., when the boat is unoccupied.

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A bilge high water alarm is a great idea. In fact IMO they should be mandatory.

But having one that goes off every time the pump comes on would just be crying
wolf and driving your neighbors crazy.

Better to have it set up just to go off if the water gets higher than normal.

FF said:

"when at dock all the sea cocks below the water line are closed for peace of mind"

This is nice if you have cable operated sea cocks ,

or dont leave the dock but every few months , but for most a PIA.

I would leave the engine operating key on a closed engine intake valve.

Click to expand...

Actually the two engine, main and gen, are the only below the water line. I had the other taken out and filled in. I start the engine in the stand up walk around engine room. The battery selector, engine sea cock and start buttons are in one location. So no trouble at all. Peace of mind. Also the bilge is bone dry so if a bilge alarm goes off something is wrong and needs looking at. With the boatnamny alarm system if an alarm goes off it sends me a text message and I can call for a status report 2000 miles away. We are in Dalas with our newest one week old, great granddaughter.