How can I keep battery from draining?

[wolfman13]

I have a newer Sylvan pontoon with a 50HP 4 stroke. Numerous times I have come out to find a dead battery. The battery is fairly new, has been charged, and has been swapped out with other batteries. It seems like something may be draining it. Nothing is left on, but it often is loosing it's charge. Is there a way to find the source/cause? There is no fish locater or troll motor on it. How can I avoid this? Install an onboard charger of some sort? Have some sort of a shutoff switch to the battery? It seems like this shouldn't be necessary but it's getting frustrating to have evening boat rides cancelled because of a dead battery. Thanks

 

[DutchMerc]

Re: How can I keep battery from draining?

The best thing is to install a main switch on the system wich separates the batery completely. If there is a current flowing through your motor, and the motor is in (salt) water, there will be a verry fast corrosion from the aluminium parts on the motor. (this is why there should be an anode on the motor). I've seen pictures from fairly new motors eaten and damaged verry bad by electrolyse whithin one year!!! Always disconnect the batery, or at least the positive pole. The draining batery might not be your biggest problem...

 

[hard-3]

Re: How can I keep battery from draining?

get an ammeter and put it in series with the positive battery cable and see if you have a drain while not running. could be alternator on motor, ignition wire could also have slight ground on it . place ammeter between + battery post and + cable. Should have no current flow with all accessories off. if it does start eliminating current draws untill you locate them all. pull all fuses out one at a time to see if it is a fused power source that is drawing current. disconnect main power wire to outboard to isolate the motor. if it is the draw on the battery, then post in the outboard section about it.

the ammeter can be a multimeter type test meter or just go to autozone and get a dash ammeter and put on a couple of wires with small battery charger type clips on them. DO NOT TRY TO START WITH THE AMMETER IN SERIES. it will tear it up due to the high curent draw of the starter.

 

[wolfman13]

Re: How can I keep battery from draining?

I believe I have a multimeter tester, but it has I think 4 different settings and each setting has some numbers ( ac, ohms etc) I don't have it in front of me. Do you know where I should have it set to do these tests? Or I will PM you when I have it in front of me. FYI-the boat is in WI, no salt water. Although a shut off may not be a bad idea anyway.

 

[DutchMerc]

Re: How can I keep battery from draining?

I believe I have a multimeter tester, but it has I think 4 different settings and each setting has some numbers ( ac, ohms etc) I don't have it in front of me. Do you know where I should have it set to do these tests? Or I will PM you when I have it in front of me. FYI-the boat is in WI, no salt water. Although a shut off may not be a bad idea anyway.

Set it to DCA or Ampere. Start with the highest setting, then scale down till you have a reading. Most meters have a range of 200 milliAmps maximum, wich is not verry much, so don't try to start with the meter attached or you'll blow the internal fuse (if you'r lucky)!!!

 

[sailinon51]

Re: How can I keep battery from draining?

Here is something I have done before, I put a test lite( solder two leads on a 1157 12volt bulb one to the case and one to the solder button then disconnect the starter wire on your battey. connect the bulb between the postive wire and the postive battery post with your starter key off and if it glows then you have a drain some where if it is a small current drain the bulb will glow very faintly.. this is a poor boy method and it works. then one a a time disconnect any fuses to each circuit till the bulb goes out. if the bulb does not lite up reconnect the starter cable and check for current draw with the bulb... ( one lead of bulb to battery post and one lead to the wire you dissconnected from postive post of battery)... hope this helps