2008 280EC Battery question

Cableguy Greg

I just launched my new to me 280EC last evening. When I got to the ramp, I put the battery switch in the 'on' position and the boat wouldn't fire up. I changed it to the 'both' position, and it fired right away. Took her to the slip, shut her down and connected her to shore power. She wasn't on shore power all that long and the admiral wanted to head out on our maiden voyage. Before I went out, I switched back to the 'on' position. We were out for a little while, anchored the boat and I never shut down the engine because I didn't want to get stranded. While on the hook, we had all of the cabin lights on, had the swim light on, along with the radio. At one point, the radio shut off. I wasn't paying it any mind until I had to raise the windlass. It wouldn't come up due to no battery power. I then switched to 'both' and everything came back on, windlass worked. The question that I am getting at is which batteries run with the switch in the 'on' position? I am guessing it is the house batteries. If it is the house, do those batteries run everything at the helm as well? The house/starting battery thing is new to me. My previous boat was a 232 cc with 2 batteries, but they were connected to everything.

Dream_Inn

My first guess is one of your batteries is dead. Both should connect both batteries together I'd think. Do you have two different types of batteries installed? Glad to hear you got the boat home safely.

Cableguy Greg

There is one starting battery and two deep cycles that are wired together in parallel. I will have to check them out today when I get back to the boat. They have been on the charger all night. Hopefully that will help, but if they are dead, then it won't. I was just trying to determine if it was the house side or the starting side. My best educated guess is the house side.

Cableguy Greg

Oh the wonderful things that previous owners do to their boats... On my house side, I have a Dual Purpose battery and a starting battery. On the other side, I have a starting battery. Guess I am going to be purchasing two new deep cycle batteries this week. The good news is that the charger says everything is charged.

MarkB

Sounds like the crank battery is not holding charge. The engine and radio run off this battery. Everything else runs off the house batteries. When you switch to both, you are using the house batteries to subsidize the dead crank battery.

Cableguy Greg

Today has been a learning experience. I found out in the panel where the battery switch is at, there is a charging system breaker for the house and engine batteries. Both of the breakers were in the off position. When I switched them on, the engine started charging them and the volt gauge was reading 13VDC. I do need to change the house batteries to two deep cycle batteries. Having one starting and one dual purpose on the house bank isn't cutting it.

MarkB

That's different. You mean your engine alternator charges your batteries via a switch?

Cableguy Greg

I think so... As soon as I reset the breakers next to the switch, I had 13VDC. Before that I had 10.5VDC. It has me perplexed...

Dream_Inn

I would say your engine itself will charge the batteries independent of any breaker (there may be an inline fuse).  But, the breaker will turn your shore power charger on/off.  BTW, 10.5 V definitely does some damage to your battery.  Greg, you have the right idea to having a great summer with your new boat.  Buy two new house batteries, connect them in parallel, & enjoy the summer!

gslpro

Greg, it shouldn't work like that.  The charger switch on the breaker panel is for the shore panel charger to be on/off.  When you run the engine, you should be charging the entire set of batteries you have.  This is done with a combiner, meaning it splits the charged from the alternator, and sends it to the house side and the starting side, but leaves them independent when not charging, so as not to drain the starting side when using the house side.  I am guessing you have more of an alternator issue.  When you combine the batteries on 'both' you send voltage to the starter battery from the house, essentially, giving it a little charge.  Now, I'm not sure when you are switching back to 'on' but running the boat on 'on' runs the engine from the starter battery.  It doesn't take all that much power to run the boat, but obviously using the windlass, lights, etc.. will run it down quicker.  While idling, you are probably not putting that much voltage out as well, if any.  Look at your starter battery and also your alternator.  Hook up a voltmeter to the starter battery, and then start the boat. You should see it go up in voltage.  Have the battery load tested at an auto parts place.  Hopefully these things help lead you to the cause of your problems.

MarkB

Greg, what rpms was your engine running at when you flicked those switches? Was your shore power also plugged in at the same time?

If the engine was idling and the shore power was plugged in, this is what I'm guessing was going on.

Your alternator will not charge unless your rpms are up closer to 1000.  Below this, there's not enough power to run the alternator, so if it was idling, the batteries weren't getting any juice from the alternator.  The switches should simply turn on the shore power (110V) to the battery charger so that it can charge your batteries. The battery charger produces 14V and energizes the electrical circuit (so even if you have a dead battery, the charger is pushing amps out to the 12V circuit that battery is on).

My guess is that you have a dead crank battery (won't hold charge). My guess is it may be because the shore power charger switch was off, and the battery was damaged in the process because of being drained too many times (need to keep these batteries topped up for crank batteries to hold life). Deep cycles are way better as they can discharge munch more current before they are damaged (so in effect, they lasted in between motor runs, when they were charged via the alternator, whereas the crank battery didn't). 

MarkB

And by the way, you don't want to put a deep cycle on to regularly start the engine.  I've been told they aren't good at pushing out high amps regularly.  The crank is great at pushing out high amps to get the starter turned over, but you need to keep them topped up for their lives to be extended.

Cableguy Greg

I am going to replace the dual purpose and starting house batteries that I have with two group 31 deep cycle batteries. I am going to get the starting battery for the engine load tested to see if there was any damage to it, or to see if it is bad. Worst case, I will try to salvage the starting battery that was on the house side and move it over to the engine side.

I am finding out that cruiser life is different from cuddy life. In the end, the reward is well worth it. The admiral and I are very happy with our purchase.

Cableguy Greg

I got the wiring diagram for my 280 from Randy Rinker today. I found out that the alternator output goes to the isolator, which goes to the battery panel at the rear of the boat where the switch is at. At that point, it goes thru the 100A breakers then to the batteries. When those were shut off by the previous owner or marina, that caused my batteries to not charge. Problem solved. Thanks Randy Rinker.

rasbury

I am not comfortable that my batteries are charging either...270....the isolator I assume is the battery switch which does not make sense as it would only charge what battery is turned on? What would the 100A breaker be???

Cableguy Greg

The isolator is a separate piece of equipment. It is a blue box that is probably mounted to your bulkhead between the cabin and the engine room. The alternator output goes to the isolator input. One leg of the isolator goes to the house battery breaker where your switch is at, then to the house battery. The other leg of the isolator goes to the starting battery breaker, then to the starting battery. That is how my 280 is wired according to the wiring diagram. The issue that I had was the breakers were manually tripped to disconnect them while in storage by the previous owner. I didn't know that they weren't charging until I was out and about and everything shut down. When I reset the breaker, I was able to start the boat and all of my voltage came back up. You might want to get the wiring diagram from Randy Rinker to see if your boat is the same. I have had it for about a week now and I was able to utilize the extra wires from the helm to connect my underwater lights. I also was able to track down my genset wiring so I can utilize them to install an inverter in my engine room.

rasbury

I did see what looked like a battery switch on that bulk head but I thought it was a shut off for the geny...I need to look at that closer. I turned if off as I am not using the genny at present until I do a good service on it...maybe I shut down my batteries from charging!

hanzelvh

@Cableguy Greg‌ , can you post this wiring diagram or mail it to me? I have had same problem and also found the breakers. There is however something else I found. When we are off the hook, so no shore power, my house batteries and my starting battery are connected through the battery charger (I guess....). Result: hardly power to start. I solved the matter by switching off the house battery breaker. Now everything is separated. I tested with using bow thruster (which is powered by house batteries) and checking the voltage of the starting batterie, no drop down any more. Thank you for providing the wiring diagram enabling me to check and find out what is happening.