Dead battery after sitting on trailer

[aidanmurphy]

Hey guys looking for some insight here. Picked up this boat with a Mercruiser 3.0 at the beginning of the summer. Did the regular maintenance and some fixes and got a brand new battery for the boat. It is a single battery setup. I have been using the boat with no issues for the entire summer until this week, I went out to the boat and the battery was entirely dead. Would not even kick on my bilge pump. The last time I had the boat out was one week ago and it had no battery issues, and I have been on the water 10 or so times with that battery before this event. I am wondering what are the chances this is a bad alternator and the battery made it this far, or what are the other likely reasons for the dead battery. Thanks

 

[briangcc]

In a weeks time almost anything could kill the battery - from a cabin/courtesy light being left on, radio powered on, running bilge pump, etc.

Could also be just an old/dead battery. There's probably a sticker on the battery with a 4 digit date on it. How old is this battery??

 

[aidanmurphy]

The battery sticker says 1/22 so it was a new battery.. I have had the boat sit over a week before with no issues and it starts right up coming back after a week. This time was different though. It's a 1991 bowrider so no cabin lights or anything and I disconnect my automatic bilge pump when storing on the trailer.

Would the dead battery be worth recharging and using again or is it going to be less efficient now?

 

[JASinIL2006]

I'd charge it and then take it to an auto parts store and have it load tested to see if it's still any good. It could be a defective battery, but the odds are much greater that something was drawing current over the week it sat idle, and that's what drained it.

 

[aidanmurphy]

I'd charge it and then take it to an auto parts store and have it load tested to see if it's still any good. It could be a defective battery, but the odds are much greater that something was drawing current over the week it sat idle, and that's what drained it.

This is my assumption as well but was confused as to why it happened just this time. I will just disconnect everything from the positive terminal when trailered for the time being so I don't kill another battery

 

[JASinIL2006]

I installed a battery switch in part because it was very easy for something to be left on that draws current.

It is simple to just turn the battery switch to 'off' when leaving the boat.

 

[Alumarine]

A common drain on batteries are the panel/gauge lights.
If you have a separate switch for them it's easy to switch them on and not notice it in the daytime.

 

[aidanmurphy]

I installed a battery switch in part because it was very easy for something to be left on that draws current.

It is simple to just turn the battery switch to 'off' when leaving the boat.

I will look into getting one of these installed

 

[ThomW]

I agree. A battery switch is easy and will ensure you can shut off the battery.

Does the boat have an automatic bilge pump with a float? A week of good rain and a bilge running could drain some battery.
Otherwise, I would place my money on a switch on the dash getting bumped resulting in navigation lights, the radio, or something else being left on to draw from the battery all week.

 

[aidanmurphy]

I agree. A battery switch is easy and will ensure you can shut off the battery.

Does the boat have an automatic bilge pump with a float? A week of good rain and a bilge running could drain some battery.
Otherwise, I would place my money on a switch on the dash getting bumped resulting in navigation lights, the radio, or something else being left on to draw from the battery all week.

It has an automatic bilge that checks every 2 min for water. But I disconnect that whenever I pull the boat out of the water. I think I will install a battery switch just as the easiest solution

 

[airshot]

Yep...get a switch installed, no matter how sure we think we are, we are still human beings and we do forget !!

 

[KM7]

The battery sticker says 1/22 so it was a new battery.. I have had the boat sit over a week before with no issues and it starts right up coming back after a week. This time was different though. It's a 1991 bowrider so no cabin lights or anything and I disconnect my automatic bilge pump when storing on the trailer.

Would the dead battery be worth recharging and using again or is it going to be less efficient now?

I recharge batteries all the time using an automatic charger. It drops the amps as the battery charges. It also has a "recondition mode" that I run on the batteries a couple of times a year. Many auto parts shops will test your battery to see if it is worth keeping but you have to charge it first.

 

[KM7]

A common drain on batteries are the panel/gauge lights.
If you have a separate switch for them it's easy to switch them on and not notice it in the daytime.

A way to aviod that is to install a lighted switch. That way you should notice that the panel lights are on even the daytime. I'm going to do that for a radio so I don't drain my battery. I will add the title of the post here once I add it.

 

[airshot]

Chances are your vattery is now junk, Batteries normally dont come back after a complete discharge. Less than a year old will probably fall under a replacement warranty. Even if this battery comes back to life, it will be a short one. If you can get a replacement, then consider a two battery set up, one for main engine and the second for ALL accessories, then you will always be able to get back

 

[dingbat]

A way to aviod that is to install a lighted switch. That way you should notice that the panel lights are on even the daytime.

How do you stop the current draw from a current leak in the bilge pump circuit, another light?

The real solution is to install a simple on/off battery switch or a 1/2/both switch if running a two batteries.

Simply turn the switch to On when getting on the boat and Off when getting off the boat.

 

[Silvertip]

Key left in the on/accessory position? Radio has a station memory function. While that alone won't typically drain a good battery, it could add to whatever drained it. And new batteries, as older ones, can die suddenly. Is the charging system working properly. It is possible to be out a couple of times with a non-functioning or improperly functioning charging system before the battery dies and it doesnn't have to be on the water.

 

[KM7]

How do you stop the current draw from a current leak in the bilge pump circuit, another light?

The real solution is to install a simple on/off battery switch or a 1/2/both switch if running a two batteries.

Simply turn the switch to On when getting on the boat and Off when getting off the boat.

I should modify what I suggested. You do not need a switch on the dash. As suggested, a battery selector switch is the best option. See attached. If you want to go one step further, An indicator light that you have power from the batteries. I do not mean an indicator that the ignition is on, an indicator that you have the selector in either 1, 2, or ALL. I dont think you need a light to tell you that the ignition is ON. Most of us would not forget to turn the key to the OFF position. The key still dangling from the ignition (and usually with a float attached) would remind us to turn the key off. I do have a battery selector switch since I have 2 batteries. I tun it OFF when ever I'm off the water. To remind you to do that just, an indicator light, maybe green since nothing is really "wrong" just power is on.

 

[KM7]

A way to aviod that is to install a lighted switch. That way you should notice that the panel lights are on even the daytime. I'm going to do that for a radio so I don't drain my battery. I will add the title of the post here once I add it.

I should modify what I suggested. You do not need a switch on the dash. As suggested, a battery selector switch is the best option. See attached. If you want to go one step further, An indicator light that you have power from the batteries. I do not mean an indicator that the ignition is on, an indicator that you have the selector in either 1, 2, or ALL. I dont think you need a light to tell you that the ignition is ON. Most of us would not forget to turn the key to the OFF position. The key still dangling from the ignition (and usually with a float attached) would remind us to turn the key off. I do have a battery selector switch since I have 2 batteries. I tun it OFF when ever I'm off the water. To remind you to do that just, an indicator light, maybe green since nothing is really "wrong" just power is on.

 

[dingbat]

If you want to go one step further, An indicator light that you have power from the batteries. I do not mean an indicator that the ignition is on, an indicator that you have the selector in either 1, 2, or ALL.

One would think it would be pretty obvious that you forgot to turn the power (battery switch) on when you turn the ignition switch and nothing happens.

To remind you to do that just, an indicator light, maybe green since nothing is really "wrong" just power is on.

Could provide two signals.....
Green = don't forget to turn off battery switch
No Green Light = Dead battery......you forget to turn the battery switch off last time.......lol

Not a fan of idiots lights let alone ones that drain the battery if not acted upon.

 

[KM7]

One would think it would be pretty obvious that you forgot to turn the power (battery switch) on when you turn the ignition switch and nothing happens.

Could provide two signals.....
Green = don't forget to turn off battery switch
No Green Light = Dead battery......you forget to turn the battery switch off last time.......lol

Not a fan of idiots lights let alone ones that drain the battery if not acted upon.

About to get off the boat:
Green = Don't forget to turn off battery switch
No Green Light = Good job you remembered to turn the battery selector to off

You just got back on the boat:
Green = You dummy, you forgot to turn the battery selector to off. You migh have enought power to start. Good luck
No Green Light = Either you remembered to set the selector to off or you forgot and have a very dead battery. You will find out very soon

Yes, obviously you will know that you did not turn the battery switch back on when the OD will not go down or the boat will not start. I was suggesting that an indicator light will help you remember to turn the battery selector off when putting the boat away. Anyone who does not remember to turn off the battery selector even with a glowing light on the dash would be even more likely to forget without an indicator light and if so they should not have a boat!!