starting battery is draining?

[muskieswen]

At the begining of the season my starting battery failed. I bought a new battery, charged it to full and installed. Two weeks later battery is drained enough so it will not turn over the boat engine. I did a drain test by disconnecting the negative terminals from the battery and touched one end of the multi meter to a terminal and one to the battery. Not sure what the readings should be but they were either 0 or .o something. I am suspecting the engine charging system. I have a 115 four stroke yamaha. What is a good way to check the charging and what readings coincide with this? Thanks for any info I get here.

[marine_man]

I did a drain test by disconnecting the negative terminals from the battery and touched one end of the multi meter to a terminal and one to the battery.

What setting (on the multimeter) were you on when you were doing this testing? Amps?

If you're sure you don't have a draw on the battery I would measure the battery voltage with nothing on and then run the motor on the hose or in the lake and run the throttle up to somewhere above 1/2 throttle - you should see a voltage rise of at least 1 volt. If you're not you've got motor charging problems - a rectifier or stator.

marine_man

[hhguide]

Make sure they have enough water.

[Dave]

Make sure your meter is set correctly. And, the meter leads are usually connected to the meter in a different location on the meter when testing current versus voltage.

[muskieswen]

Yes amps was the setting. I see I typed ohms, My fault. So the way I see it put the multi meter on 20 volts dc reading, hit the lake and there should be a minimum of 1 volt increase? On the other drainage test I did, should you read a zero on the scale or will there always be a relativly small amout of current coming thru?

[Tom7227]

Ohms measures the resistance of the line - if there's an opening it won't register. So you should be able to go from the battery to any device and check to see if there's a reading. If there is a reading, and you think the device is "off" you have a problem - most likely a short someplace. The meter should show zero when you turn it on. If you touch the two leads together it will give you a reading, and that's how you know if the ohm part of the meter is working. Make sure you have the leads plugged into the right sockets - on mine I have to change the socket if I go from DC volts to Ohms.

[Jeremy airjer W]

When your checking amps your leads will have to be in the right "sockets" also. The amp function is usually protected by a fuse in the multi-meter. If the fuse is blown it will read zero amps all day long!