Battery Draw Down
 

I took my boat out of storage today but stopped by last week and put the batteries in, and hooked them up...when I got there today and trimmed the motors they barely had enough juice to lift the motors. The key was off and the master power switch was off. Where do I start?

I'm no expert, but from my understanding, the motor will be drawing on the cranking battery even with the master switch off unless you specifically have a breaker between the motor and the battery.

I leave my charger plugged in all the time when the boat is on the trailer.

I'm sure I will be corrected if I am wrong...;)

Juls

[QUOTE=Juls;1410776]I'm no expert, but from my understanding, the motor will be drawing on the cranking battery even with the master switch off unless you specifically have a breaker between the motor and the battery.

I leave my charger plugged in all the time when the boat is on the trailer.

I'm sure I will be corrected if I am wrong...;)

Juls[/QUOTE]

Juls is correct. The engine's computer can still draw current when the master switch is off. However, I disagree with leaving the batteries on a charger all winter (where I am, winter is just about over now). If you charger or a battery fails, you could have bigger troubles, the worst case scenario being a fire. I prefer to disconnect all fully charged batteries from everything (all cables removed) for winter storage. At low ambient temperatures, a fully charged battery can be stored for months, and only require a few minutes of charging in the spring.

[QUOTE=boat nut;1410927]However, I disagree with leaving the batteries on a charger all winter[/QUOTE]

He just put the batteries in, so he's not talking about keeping the charger plugging in all winter, but rather...right now.

During the fishing months, I leave it plugged in so that I know when I go out I have fully charged batteries for the day.

I never have a boat to worry about in the winter, so your advice is probably good for those that do. It just doesn't apply to me. ;)

Juls

Pretty simple (but maybe tedious) matter to disconnect all the electronics and connect them one-by-one with even a cheap ammeter hooked to the battery and the respective lines out at the battery. It's easy with two people, and can let you diagnose vampires.

I had a used boat that the owner had gone through batteries every year. The radio/CD drew a surprising amount of current. Once the CD half of the radio was disconnected (then the whole radio switched) there was virtually no current draw on the battery in storage.

The plug you had charger plugged into didn't shut off when you shut off the lights did it?
Don't ask why I would think of that..
Dave

Do you have a kicker with a trollmaster? It'll draw the battery down over the winter months

Ok, might not of been 100% clear...I know the big motor has a minimal draw and maybe my kicker does to for that matter...I do believe however from when I hooked the battery up an arc occurred when I hooked up the wires that feed the dash fuse box...I have both the 115 and the kicker hooked to the battery which I know is at full charge. I dont however have a 3 bank charger so leaving the cranking battery charging is not an easy option, its doable, but not easy... Its a Lund Mr Pike boat, and like I said, I think it has to do with the boat, not the motors...I do have a radio, cd, but the only thing it keeps a small small amount of power for the internal clock, otherwise all power to the radio is killed with the master switch as well...Any help now that Ive cleared it up a bit.

[QUOTE=bridgeman;1410960]Do you have a kicker with a trollmaster? It'll draw the battery down over the winter months[/QUOTE]

NO!!!!

Walleye,
With everything set up as you had in storage, simply remove the wires from the battery post that has the least number of wires on it.
Then - take a bolt and bolt all of the wires together that you removed from the terminal.

Then, take a multimeter set on amps or milliamps scale and put it between the bolted up wires, and the battery post. It doesn't matter if this is the - or the + terminal. If the meter reads the wrong direction, simply reverse the meter connections to the wires and the battery post.

Now, if you have any reading at all on your meter, you are getting a discharge current from your battery.
So, now it is simple to find it. Just unbolt one wire at a time from the wires that are connected to the battery post and remeasure. Continue to measure until you find the wire or wires that are causing the battery discharge.

Once you have found the wire, or wires causing the discharge, follow them to their source to determine the source and the remedy.

You may find that your best and cleanest option would be to put in a master battery disconnect switch, so that everything from the battery would be run through the master battery disconnect switch, so that the battery would be 100% isolated during down time.

Don't discount checking the wire going to the on board battery charger if you have one. A frequent source of battery discharge is a defective on board charger that is not turned on or plugged in. If part of the charger becomes defective, battery voltage may be drained off back through the charger, if the charger is not plugged in.

Good luck
REW