Start Battery problem

Ashley Lynn · Posted: Sun Aug 19, 2007 9:54 pm Post subject: Start Battery problem

I have an intermittent problem--now more often than not. The start battery (battery #1) will not start the boat, nor will it operate the trim on the motor. However, battery #1 still can power everything else (electronics, etc)..so, I don't think the problem is with the #1 battery.

I have a perko switch (Off, 1, All, 2). I have checked the #1 battery connections and the connections on the switch and they are tight and no corrosion. The motor will start on #2 and all. It will not on #1 (13.3volts read across #1 battery and 13.5 volts across #2 battery).

Any suggestion as to were I should look next?

Thanks in advance.

BrentB · Posted: Sun Aug 19, 2007 10:18 pm Post subject:

Are you using a lead acid battery? If yes then check the specific gravity of each cell and/or perform a load test.

http://www.batterystuff.com/battery-products/EZB1100D.html

http://www.exide.com/faq/faq_marine.html

If battery is ok, recheck the connectors and battery cables. use a digital volt meter to check resistance of each battery cable.

Not sure the best method to check the battery selector.

m2cw

seahooked · Posted: Sun Aug 19, 2007 10:21 pm Post subject:

The battery voltages look good- especially if your measurements were taken with some load on the batteries. Also, I would not think that an actual battery problem would show up as intermittent. The same however cannot be said of the switches.

An easy way to narrow down the problem might be to disconnect the house battery (by removing the wire(s) on the negative battery terminal), and trying to start the engine on the 'all' position. If it works in 'all' but not in '1', I believe you've determine the switch has a faulty contact in position '1' and needs to be replaced.
Good luck.

thataway · Posted: Sun Aug 19, 2007 11:53 pm Post subject:

Switch battery terminals in the switch--switches have been known to be bad under high loads. By switching the terminals you can determine if one of the switch contact is bad. Another option is to connect the battery directly to the engine and see if it starts it.

13.3 and 13.5 battery voltages? Is that with the battery charger on? That sounds like float voltages with a charger. Turn off the charger. Let the battery sit, and then load test them. Testing with a battery charger on will not tell you the health of the battery.

The battery should be from 12.6 to 12.7 volts, resting after being fully charged (might be slightly higher by a few tenths of a volt, depending on how long after charged).

Ashley Lynn · Posted: Mon Aug 20, 2007 9:09 am Post subject:

The voltage reading of 13.3 and 13.5 was with the chargers on.

BrentB · Posted: Mon Aug 20, 2007 9:11 am Post subject:

What is the recommended wire type and guage for this boat?

thataway · Posted: Mon Aug 20, 2007 10:09 pm Post subject:

Battery voltage with the charger on is worthless. You are reading the charger in float mode. Put a load on the battery at least 30 min after turning off the charger. For example, turn on all of the cabin lights for 10 minutes--do this with both batteries--and then see what the voltage is.

Another way, is to clamp the volt meter probes to the battery terminals and crank the battery--it may drop to 9 volts but compare the two batteries. (Probably not that much with a low HP outboard).

Ashley Lynn · Posted: Tue Aug 21, 2007 4:36 pm Post subject:

Dr Bob,

With the chargers off. I placed selector switch to #1 and turned on all interior lights for about 15-20 minutes. Voltages across battery #1 was 12.3, battery #2 was 12.89. When I tried to crank motor, I did not see a change to battery #1 (I set the Fluke to hold)..I did not see or hear the meter change--still the 12.3volts.

I did notice that when I selected just #1, I could hear a crackling or popping sound coming from what appears to be the battery. I do not think there was any arcing. Is it just a bad battery. I only bought the boat at the end of April. I do notice a little acid or what looks like acid on the top of the battery....none on battery #2.

I have not yanked the battery out of the lazarette yet. ....too dang hot!!

I think I need a Beer

thataway · Posted: Tue Aug 21, 2007 5:05 pm Post subject:

The battery voltage (12.3 volts) shows the battery is close to 50% discharged. A good battery should still be in the 12.5 to 12.6 volt range. I susepct a bad battery. It should be covered under warantee. I would also double check the switch and look for any shorts etc. Occasionally one gets a bad battery...stuff happens. But it may have been excessively drained by a short or moderate amount of power drain. For example I wire my sterio's so that the memory is off when I am not using the boat. Sure I have to re program the "presets" but it does not drain my batteries....

Keep us in the loop- as to what happens. But get a new battery.

Ashley Lynn · Posted: Tue Aug 21, 2007 7:04 pm Post subject:

OK..

I removed the #1 battery and its voltage out of the circuit is 12.55. I connected just the negative cable and the positive cable going to the switch. It is still 12.55 volts. Cranked the motor fine. Watched the voltage drop below the 12.55 but gradually rose back to the 12.55volts.

So, I then connected the other two negative cables (common - bus) and negative that runs directly to the negative terminal of bat #2 (is that correct?). I checked voltage again, still 12.55. I started reconnecting the 4 other positive connections to see if they drew down the voltage, they did not (I then took them back off--didn't want to rush into anything).

Here is the current wiring:

Bat #1
Negative has three cables (to the motor, to bat #2 negative, and to the negative bus)
Positive has one cable going to switch position #1

Bat #2 has negative going to bat#1 negative and positive going to switch #2 positive.

Switch also has hot going to 50 amp breaker and positive going to motor.

that is all I have connected at this time.

I continued to watch the voltage (12.55) and it slowly began to drop to 12.47.

**EDIT** The switch was in the #1 position when the voltage started to drop.

I since place to switch to off and the voltage started climbing again...currently back up to 12.52

any insight?

Ashley Lynn · Posted: Tue Aug 21, 2007 7:28 pm Post subject:

The more I dig, the more confused I get Cry

I reconnected everything:::

All these reading are across bat #1

switch off bat1 = 12.52volts
switch 1 bat1 = 12.52volts
switch all bat1 = 12.69volts
switch 2 bat1 = 12.65volts

switch back to off bat1 now = 12.61volts

Cry

I'm starting to like these icons...this is how I actually look right now.

Time to have a cold one and jump in the pool...heat index 101......
and I think my brain is a little bit warmer than that.

Cheers!!!

Bob

thataway · Posted: Tue Aug 21, 2007 8:41 pm Post subject:

What is pulling the battery down? There has to be something which has dropped the voltage--and may have brought the voltage to a low level several times. Is the charger left on all of the time?

Often this is the sterio " memory). Is there something else which is pulling the battery down? If it is less than 10 amps, they you can measure it with the digtal volt meter--more than 10 amps, you need either a special amp meter or shunt to measure the power draw.

I am still leaning toward a bad battery--so you need to have it load tested. The battery voltage comming back up after being connected to the #2 was a slight surface charge being given to the #1 by #2 battery.

The connections sound fine. The 50 amp breaker is correct and this circuit goes to the console. There is often a second circuit going directly off #1 battery to the bilge pump--occasionally a bad bilge pump switch/pump can cause a drain.

Grab one of those $89 AC units at Wally world, for the AC when you are working on the boat--of course it doesn't help the cockpit!

Ashley Lynn · Posted: Tue Aug 21, 2007 10:11 pm Post subject:

The battery chargers are rarely on. I usually charge the batteries via the alternator while under way (switch set to all). I do have the stereo memory and also the bilge connected to start battery #1. All the electronics are connected to battery #1.

thataway · Posted: Tue Aug 21, 2007 11:35 pm Post subject:

I am going to postulate that your #1 battery has been run down to the point where it is damaged. This can happen with a new battery. Battery life is affected by the depth of discharge. If you never discharge the battery less than 25 to 30% it will last a long time. If you discharge it to 11 volts a few times it will significantly lower its life span. I would turn off the radio memory. If you leave the boat in storage, then put a solar pannel on the roof. I have a Road Trek Rv, I leave in Las Vegas (same place I had the C Dory22--and did the same solar cell on the C Dory, to be sure that the batteries were kept up. Just one of the small pannels will keep the batteries from the self discharge and damage. I have been doing this for 4 years--and leave the RV (and did the boat) for 6 months or more, and the battery (turned off) was always ready to go.