Dead Battery

tablerockboater

Petty Officer 1st Class
Joined
Apr 23, 2005
Messages
207
Not specific to pontoons, but . . . the last two times we have gone to our pontoon, the battery has been dead. It never has been before, and the only thing I might have done is that after a rain, I had wiped everything down with a towel. I'm thinking I might have tripped one of the toggle switches . . . but none of them appear to be.

I have a multimeter, and wonder what I should do to see if there is any draw when I think I have everything shut off?

Thanks.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,501
Not specific to pontoons, but . . . the last two times we have gone to our pontoon, the battery has been dead. It never has been before, and the only thing I might have done is that after a rain, I had wiped everything down with a towel. I'm thinking I might have tripped one of the toggle switches . . . but none of them appear to be.

I have a multimeter, and wonder what I should do to see if there is any draw when I think I have everything shut off?

Thanks.

As a quick test, see if the positive battery terminal sparks when removed from the battery terminal.

If it sparks, shut off circuit breakers one at a time to see if it stops. the offending devices is connected to the breaker that makes it stop.

I've had this happen twice in the past. Both times it was a bad bilge pump motor.
 
Last edited:

bigdee

Commander
Joined
Jul 27, 2006
Messages
2,665
My battery drains down too after a couple of weeks. There was no current draw when I checked it with a multimeter so I'm assuming rain or dew is causing it. I used to disconnect battery but a better solution was a cheap solar panel from Harbor Freight for less than $20. It will keep battery charged. I also have one on my shed to keep my garden tractor maintained.
https://www.harborfreight.com/15-watt-solar-battery-charger-68692.html
 

lmuss53

Lieutenant Junior Grade
Joined
Sep 9, 2008
Messages
1,227
I got a pair of those made by Coleman, they never did much at all as far as I could see. I think the memory in the stereo was pulling out more than they were putting in. I finally got a big keyed kill switch and put it on the battery right at the hot connection. I have to reset the radio every trip, but the battery hasn't died for a while.

You can expand on dingbats test by setting your meter to the amp setting and probing from the disconnected cable to the battery post. The meter will tell you how much current is flowing.
 

bigdee

Commander
Joined
Jul 27, 2006
Messages
2,665
You can expand on dingbats test by setting your meter to the amp setting and probing from the disconnected cable to the battery post. The meter will tell you how much current is flowing.

I did......zero with everything turned off. Got tired of disconnecting battery that is why I chose the solar.
 

tablerockboater

Petty Officer 1st Class
Joined
Apr 23, 2005
Messages
207
Thanks.

I have a Sunforce solar panel setup on our "Summer" boat dock, I am Harbor Freight guy and know they have that 100 Watt one, I have seen the little ones, but never thought about it for keeping a single cranking battery up. Good idea.

Disconnecting the battery was already on my list, but putting in a shut-off switch was not.

Good ideas. Thanks.

I'm still in diagnostic mode. It appeared to be fully charged this morning.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,754
the last two times we have gone to our pontoon, the battery has been dead

It was the battery.

Once a battery goes dead, it can and in most cases it is damaged

So a new battery will get everything working again and may fix the issue "IF" the battery was the original problem. Keep close eye on it to make sure its not something else. Like others have posted, do some testing to make sure
 

cassadypaul

Cadet
Joined
Apr 22, 2016
Messages
23
Did you try a static current draw test? Put your DVOM on the 10 amp setting and connect the leads accordingly. turn everything off. The connect the meter is SERIES with the battery. If it reads zero try moving down to the miliamps scale. Depending if you have a stereo or a newer power plant with EFI there might be a normal baseline draw. (I do not know what that figure would be) If you see something still drawing say 5? amps you know you have a problem.
 

cassadypaul

Cadet
Joined
Apr 22, 2016
Messages
23
DONT FOGET to put your leads back to the resistance/ voltage reading ports. Your meter is a direct short when set up in amps.
 

taenglish

Recruit
Joined
Mar 22, 2018
Messages
1
What is a batery "isolator"?
I just bought my first boat and I was looking to install a 3 bank battery charger and saw a 3 bank "isolator" on iboats. Is this the same thing?
Thanks
 
Top