340 dancer - how long should batteries last on the hook?

D

DaleM

Member
Aug 5, 2009
690
Mt Airy, MD
Boat Info
340 Sundancer
Engines
Twin 8.1 Horizons
I saw a few posts where folks are able to stay on the hook up to two days and still have power to fire up. I ask this because I have 4 group 27s - two stbd, two port. The 4 batteries of each side are wired in parallel in two banks. Two on the port were replaced two seasons ago. The stbd bank was replaced this season before splash. We stayed on the hook this weekend and when we got up Sunday morning the boat was dead. I have a jump box onboard so after some screwing around was able to get the hatch up and mains running. The other weird thing is the port side batteries appear to run the generator which is on the stbd side based on where I could get cranking power when connecting the jump box.

I don't have anything "extra" on the boat using 12v. All lights have been converted to LED. I do have the cabin fridge and the cockpit fridge. I will admit that I did not turn off the 12v side for fridges before going to bed. Would that be enough to draw down the batteries in that amount of time? That's about 13hrs with just the fridges running. It was mentioned to me that I should get a lot more time out of them. If I'm smoking something thinking they shold last longer, I'm ok hearing that too.

I was also thinking maybe I have something else drawing down the batteries but when looking at the analog amp meter they are sitting at 0amps (that I can tell). Someone also mentioned that maybe the charger isn't putting out what it should - but from the volt meter in the cabin it's showing it's putting out about 13.5-14v. I have not verified with a DVM yet.

any ideas??
 
After replacing all of my batteries on my 340 with Duracell (Deka) Group 27's I was able to go 2 full days, 1 night, with everything on and not running the generator. If I went 2 nights I'd run the generator to top everything off before the second night but I think I could have maybe gone the second night as well if I were a little more judicious with turning things off.

In the scenario above I would have had both fridges on, occasional water pump, stereo (not super loud) and the anchor light all night long. And with 3 kids the vacu-flush does plenty of running :)

Maybe one of your fridges is giving up the ghost? It seems like those are the biggest consumers of power on the hook...
 
Stee6043 said:
Maybe one of your fridges is giving up the ghost?
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That's always a possibility. I did fail to add that I did have the anchor light (LED) on and like you the occasional water pump/head cycle. Maybe the fridge is set so cold that it doesn't stop running? Everything is cold and the freezer section keeps things frozen - I know that's a very non-scientific way of looking at things :)
 
It definitely sounds like either you have a failing battery or something else going on, electrically. I once went 4 days and 3 nights on one group 27DC. I did this on purpose as an experiment. I had the fridge going (granted only one of them, but the fridges, once up to temp don't draw a whole lot), some radio use, water pump/head of course, the anchor light at night and of course some interior lights (LED). I ran the engine for no more than 1 hour over that entire time period - just to move the boat to a new spot. On the last day, that battery still had plenty of juice to start the engine. This was on my 260DA, single V8. But it sounds like very similar use to what you were doing.

Do you have DC batteries, or starting batteries?
 
DaleM said:
That's always a possibility. I did fail to add that I did have the anchor light (LED) on and like you the occasional water pump/head cycle. Maybe the fridge is set so cold that it doesn't stop running? Everything is cold and the freezer section keeps things frozen - I know that's a very non-scientific way of looking at things :)
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Yeah, I just know that on my 400 my Norcold is on it's last legs and runs a lot more than it should. I did not have that problem on my 340. Without the fridges running you should be able to go weeks on 3 Group 27's!!

Perhaps try that sometime. If you overnight a lot try isolating it to one or both of your fridges to see how long the batteries last.
 
Lazy Daze said:
Do you have DC batteries, or starting batteries?
Click to expand...

I have dual purpose batteries. I'll go the route of unplugging shore power while at the dock and see what kind of life I'm getting by isolating fridges and other 'stuff'. That's about the only way I think I can do it.
 
DaleM said:
I have dual purpose batteries. I'll go the route of unplugging shore power while at the dock and see what kind of life I'm getting by isolating fridges and other 'stuff'. That's about the only way I think I can do it.
Click to expand...

Just be sure you don't kill 'em too dead. :) Also make sure you don't have any leaks in the boat causing bilge pumps to run non-stop before you start this kind of testing!
 
You might want to, after fully charging, disconnect the ground cables from each battery. Let them sit for a while and then check the voltage directly at each battery with a meter. Ideally, put some kind of 12V accessory directly on the battery (like a ski tube inflator) for a few minutes, first, and then let the battery sit for a while. But this is decent way to quickly things.
 
Just to add to what’s already shared, Don’t you have a jumping switch that connects the 4 batteries when two are dead to start the boat? That’s pretty standard, but not sure when that came out.
 
I do have the emergency bridge switch but we were so dead that didn't do any good. Something just isn't adding up.
 
I invested in one of these. Works very well.
You should have been pulling max 8-10 amps on the house side. Maybe 2 amps on the start side. Should have lasted 12 hours. Need to do a load test. Should really have group 31's all around.
51wEMqpZDUL._AC_SY400_.jpg
 
Something sounds wrong. You have a draw. Start by turning everything 12v off. Then turn things on one at a time and watch your amp meter. You will find the culprit.
 
IMG_4230.JPG
My money is on the fridges being the culprits, especially if you are in and out of them. Unless you have cold holding plates, or turn them way down, they are going to run batteries down. Your genny should have an isolated starting battery so you can always start it, and then run your battery charger for the others.
 
I haven't opened the main 12v panel in the ER to truly trace how things are wired. All hots go into that panel, including the large gauge "hots" off the start of the genny and mains. My ability to isolate seems limited. There are three main solenoid switches on that panel in the ER, as well as in the cabin power cabinet labeled "Starboard", "Port", "Genny" respectively. When you turn them off you can hear the relays tripping. If I remember right, shutting down the Starboard side kills "some" of the 12v systems in the cabin, and Port kills other 12v stuff (lights, etc). Almost like its wired with the "house" systems on both batteries without a dedicated "start" set. I need to look at that more closely and map that out. There isn't an apparent isolated battery for the genny that I can see because it's all inside that panel.

It doesn't seem to me as straight forward as my 280 that had actual battery "knob" dials that you selected port, starboard, or "both". In that set up, you could run the house on one battery and keep the other for starting. My wiring schematics are on the boat so I can look at that either.

I also agree with turning things back on 1 at a time to see what the meter does.
 
My 340DA is a 2002 vintage. When I replaced batteries, I upgraded everything to four Group 31 Interstate Marine AGM's. My house load runs on a parallel bank of two of them, which also is the starting group for one engine. The other engine, and the genny each have their own batteries. If I did run the house down, I would still have the generator and the 2nd engine in good shape to start. I haven't had that happen, but I did run the house bank down low enough with the old batteries that I used the emergency start bridge to tie in the other engine's start battery. Those were Group 27's, and several years old. I've had great results the past 2 years with the Group 31's.

What you describe, having your house loads split where both banks could get drawn down leaving you with nothing to start doesn't sound like a good set up. Maybe adding a dedicated starting battery for the genny would be good, so you can always get that fired up? That's probably easier to add than changing how your house loads are distributed.

For us, in practice, the genny is on twice a day when we're on the hook. Maybe cooking/coffee in the morning, then in the evening showers, dinner, and of course, you need that genny for the industrial strength bar blender... The side benefit is that running it for a couple hours each day keeps the batteries pretty happy too.
 
be_prepared said:
My 340DA is a 2002 vintage. When I replaced batteries, I upgraded everything to four Group 31 Interstate Marine AGM's. My house load runs on a parallel bank of two of them, which also is the starting group for one engine. The other engine, and the genny each have their own batteries. If I did run the house down, I would still have the generator and the 2nd engine in good shape to start. I haven't had that happen, but I did run the house bank down low enough with the old batteries that I used the emergency start bridge to tie in the other engine's start battery. Those were Group 27's, and several years old. I've had great results the past 2 years with the Group 31's.

What you describe, having your house loads split where both banks could get drawn down leaving you with nothing to start doesn't sound like a good set up. Maybe adding a dedicated starting battery for the genny would be good, so you can always get that fired up? That's probably easier to add than changing how your house loads are distributed.

For us, in practice, the genny is on twice a day when we're on the hook. Maybe cooking/coffee in the morning, then in the evening showers, dinner, and of course, you need that genny for the industrial strength bar blender... The side benefit is that running it for a couple hours each day keeps the batteries pretty happy too.
Click to expand...
+1 on genny twice a day. Once in AM and once in PM. We use everything liberally and never have to worry with this routine. I switched to 31’s years ago and that helps a lot. I was sick of topping off the wet cells, so changed to AGM’s this season and upgraded the battery charger to one that had an AGM setting. So far, I really like the set up.
 
Just curious, how do you get your engine hatch up without power?
 
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