battery question

brianflhrci

Took our 290 out today and noticed once we dropped anchor and shut the motors off the radio went off as well.  I thought I'd check the batteries just to make sure things were connected properly after winterization and the hatch was extremely slow to the point where it couldn't open all of the way.  Haven't had a chance to get a volt meter down there yet but didn't know if anyone had any thoughts or a similar experience?

DanD2

Check to make sure your connections are good.

Cableguy Greg

Check the battery breakers in the battery panel. Early last season my breakers were tripped, so the batteries weren't charging. As soon as I reset the breakers, everything went back to normal.

brianflhrci

Thanks for the tips guys.  Heading back down to the docks in a few.

MarkB

Radio runs off ignition switch. Did you turn the switch to Accessory mode by moving it counter clockwise from off position?

brianflhrci

I just had the switch off, last year the radio would stay on.  The GPS continues to work also.  I put a voltmeter on all three batteries two were 13.6 and one was 11.2.  Could it just be time for a replacement?

MarkB

11.2V is low. But GPS should be on house battery and the radio on the crank battery, powered by the ignition switch.

212rowboat

11.2, you've got a dead cell, and a dead battery... Its gone.  even if you recover it with a reconditioning charge, the fuse is lit.  

rasbury

you can't just mess around with batteries....will leave you high and dry. If I run out of things to do, I go buy new batteries...

howardrams

I'm agreeing with Rowboat that the 11.2 is gone.  Even a discharged healthy battery should still read 12 under no load.  My boat also came from the factory with both radios hot regardless of the ignition key being in or not.  I'd check the 2 batteries which both read 13.6 separately with the cables unclamped, just to make sure both are OK.  Mine both read 12.88, disconnected.  With engine running, alternator output should be about 14.5V

212rowboat

2.1 x 6 = 12.6, and resting voltage of a '12v' battery. Hitting it with less than 13.5v won't charge it.. perfect isbetween 13.8 and 14.3, but you can overcharge to 14.5 on a surface charge battery... A deep cell you'll want those thick plates to slowly take charge, or, right at 14v. The 11.2 is a goner. A cell is straight up dead. If that battery is in parallel with other batteries in the system that aren't the same capacity and type, isolated it. That may be why it's deaderndead.

brianflhrci

That was another question I had....I am the second owner and int he previous two years the radio would play with both keys in the off position(or not in the ignition).  Is this normal or to I need to have the keys in the accessory position?  How do I tell which batteries are the starting versus the house battery.  The previous owner has put three starting batteries in I guess to save money.  I am full of questions, I really appreciate the help guys and am starting to shop for a new battery.

212rowboat

brianflhrci said:

That was another question I had....I am the second owner and int he previous two years the radio would play with both keys in the off position(or not in the ignition).  Is this normal or to I need to have the keys in the accessory position?  How do I tell which batteries are the starting versus the house battery.  The previous owner has put three starting batteries in I guess to save money.  I am full of questions, I really appreciate the help guys and am starting to shop for a new battery.

the radio wiring seems hit and miss, and likely determined by the person at rinker who wired it that day... having it wired directly to power instead of though ignition switched power is only a problem if you forget to turn it off.  there should be two power leads off a radio- one for constant power and for clock and memory control, and one for ignition power-or powering the things receiver and functions. 

the find the starting battery, start at the starter slave solenoid atop your engine near the main breaker- follow the heavy gauge wire back to the battery.  pretty much that simple.  you may encounter a battery switch, allowing you to select which battery is the starting battery and which isn't, or if the amps are being pulled from both at the same time. 

three batteries being the same isn't a problem, especially if they are all receiving charge from the same source (alternator), and they are all touching (as in a series).  However, it is better to have different batteries for specific purposes.  your starting batteries, for instance, are better to be 'surface' batteries, which are capable of discharging more amperage quicker than deep (thick cells) charge batteries.  they emit the 12.6v, but they do so slower than the surface 'starting' batteries.  running a boat's accessories while afloat, you'd benefit by isolating the 'house' (deep charge) from the 'starting' (high amperage output) batteries, and so they charge (from the alternator) at different rates, as opposed to all three being hit with the same voltage no matter what.  

I don't know how PCM's on boats are managed.  It's times like these I wish Al was still around.  On my truck, however, the PCM regulates the regulator built into the alternator.  Battery voltage is monitored by the PCM, and if while the engine is running the PCM senses a lower voltage circumstance, it opens up the floodgates and hits it with full capacity charge of around 14.5vdc.  Anywhere from 13.8 to 14.5vdc is capable of charging, while 13.2 to 13.5vdc is only capable of maintaing the charge.  If your batteries are fully charged and a load doesn't drag them down, the PCM will trickle charge and monitor them, instead of blast them.  

If the above is true for a boats PCM, and if you are using multiple batteries that aren't isolated or switched (better to be isolated), then the PCM, as smart as it is, doesn't know and will either trickle or blast dependent on the total perceived voltage.  

The batteries themselves, being in a series, will trickle from one to another until they're equal, just like water being distributed to cups would.  So, if one is full (say, your starter battery) and the other requires juice to recharge (house battery; thick cell), the starter will lose charge as it's being transmitted over to the un-isolated house battery.  This is **** the starter battery, which is designed for hard amperage draws in quick discharge of turning that engine, only to be instantly rewarded with the running engines alternator- instead now, it has another source drawing it down (the house battery)..  

If'n I were you, I'd map out how my battery and charging system is laid out, and I would isolate the battery feeding the house items... I'd switch the batteries feeding the starter... I'd leave the switch in the A+B mode while underway, and switch it back to one or the other while at harbor without a/c power connected, just to know I'd have enough power in the non-switched battery to get me going again if I drained the other two... while charging through a/c, though, I'd make sure you're back in the A+B setting.   

brianflhrci

Holy crap 212 great info!  Thanks for taking the time to respond.  I'm planning a nice day of crawling around in the bilge and tracing wires to follow your advice.  Thanks again!

howardrams

Don't know if you can see this well enough but it's what you might find.

brianflhrci

More news on this...The radio doesn't work when the key is in the "on" position either  and the fridge seemed to completely defrost today while we took a cruise today and were on anchor for about 2 hours.  I check all of the breakers and they were fine.  I've replaced the house battery but maybe there is still a bad connection some where?  

MarkB

time to get the multimeter out. 

brianflhrci

Crazy end to the story....The ground of the house battery was loose.  Don't know why the radio didn't work since it's an ignition connection but once I found the loose connection and connected a good ground we are 100%.  Thanks again for all of the info and support on this forum!

DanD2

That's why I stated to check your connections...your symptoms sounded to me like something was loose or a corroded connection.

Dream_Inn

Good find and good news!  Now you know for next time.  I've seen a bad ground do many strange issues!