Battery Capacity?
djstewy
Member Posts: 37 ✭✭
Hi All,
I'm taking delivery of a 2007 Rinker 280 EC tomorrow and I'm curious about what others experiences have been with battery capacity keeping electronics going for longer periods of time. My boat has two batteries currently, both are Interstate Marine batteries, one being a starter and the other a deep cycle house battery.
The fiancee and I plan a lot of overnight stays away from dock power and I'm wondering what to expect for the house battery keeping up with the two fridges, anchor light, and any cabin lights being on. Having a genset is a new thing for me as well so I'm wondering how often others run theirs and for how long to keep things charged up?
My old boat didn't have a generator and I was terrified of being left out on the water without battery capacity, so I always switched things completely off when floating except for the radio. I'm looking forward to having more options with this boat, but I don't want to make any assumptions and get myself in trouble. I'm also debating adding a second house battery to increase capacity, but that might wait until the end of the season.
Thoughts?
Derek
Comments
Hey Derek,
Is your deep cycle a 31D (larger capacity) battery? A lot of guys I know overnight away from shore power, will have at least 2 x 31D deep cycle batteries on the house circuit. If you do add a battery, it would be good for you to wire them on the side that will balance your boat better (so you don't list as much with all 3 batteries on one side, perhaps with a full water tank as well to add to it).
I'm assuming you're aware that your crank battery should be isolated from your house circuit, via the battery switch (and functional isolators), so that even if you do dry up your house battery, you should always have juice in the crank battery.
The other thing I did was purchased a jump-starter battery. It is essentially a portable battery, something like this:
http://www.westmarine.com/buy/west-marine--600a-jump-starter-with-air-compressor-and-12v-power-supply--12972378
It is your last resort, not connected to anything, and there for emergency situations.
Boat Name: King Kong
"Boat + Water = Fun"
Yes, combine is only for emergency situations when for whatever reason your crank battery is dead and you want to run the engine off your house battery. These would be unusual circumstances, and not good practice to do regularly. Also you never want to change that switch while the engine is running. That will blow your isolators. Both batteries will be connected to the alternator of the engine. In order to avoid that particular point from being the bridge to connect both batter circuits, the cables are run through isolators before connecting to the engine. These basically make sure the current from one battery can't get into the other circuit (and start draining it). Your isolators should be fine if proper procedure was always used with the electrical circuits. I'm not a genius with electrics, but I believe if the isolator is blown, the boat would still work, it just means your alternator is now bridging the two circuits, and your house and crank batteries are essentially in the "combine" mode (even though the switch isn't).
Boat Name: King Kong
"Boat + Water = Fun"
Yes, if you keep it off the combine, they "should" be isolated. BTW, congrats on the new ride!
unless your batteries are brand new, I'd just recommend trying out what you have first & see how it goes. When you add another house battery in parallel, you want them both to be in the same condition (new probably since you would be buying it). One suggestion, turn your fridges down to maybe the half way mark when you are anchored. When the generator is running, turn them up. This will help conserve the batteries a lot. I'd say in general for a weekend out on the hook, run the genny about 2 hours in the morning, maybe an hour in the afternoon, then 2-3 hours in the evening. At least that is what we do and it works out pretty well. You will kill the batteries if you let them go down too far (below 12V) very often.
Isolators, well, follow the cables from your battery charger. Do they go directly to your battery, or do they go into a small box that has cables that go to the battery. If they go to the box, that is an isolator.
Dream 'Inn III -- 2008 400 Express
Dream,
Thanks for the tips, I'll take a look at the batteries tomorrow to see how they're wired. I also had no idea you could adjust the fridges so I'll take a look for that as well. Out of curiosity, any guestimate on how much fuel the generator uses when it's running?
Derek
PC BYC, Holland, MI
I always use the 1gal/hr for genny estimation.
RY, I can't say I've ever heard, but I've known people that removed them cause they weren't happy with them.
Dream 'Inn III -- 2008 400 Express
RY, I agree for anyone using two different types of batteries. The problem is the voltage drop due to the diodes. But yes, it is a necessity for keeping that starting battery ready to go and allowing full use of the house battery(s).
Dream 'Inn III -- 2008 400 Express
Derek,
I do it a little differently depending on how long I am going to be on the hook. If it is just one night and back the following afternoon, running the generator for 30 min to an hour in the morning is fine. If its 2 nights out then I run it for 2 hours on the first morning then 1 more sometime before we go to bed and usually another hour on the 2nd morning. Always seemed to work for us. Oh, and 3 nights.........ain't going to happen. We would be out of water and heading in to get more!!
Thanks.
@RinkerYan I heard that moving the battery switch while the engine is running could blow the isolators.
Boat Name: King Kong
"Boat + Water = Fun"
The battery switch on the 280 is a "make before break" switch, so it can be moved from the "on" position to the "combine" position and back without blowing anything out. There is an isolator on the 280. It is the blue box next to the battery charger in the engine room. There are also 2 battery breakers in the battery switch panel. Make sure they are not tripped. When I got my 280, the previous owner used that to shut off the batteries. I didn't know it and my batteries were not charging. If the breakers are in the "tripped" position, the batteries won't charge. I got the wiring diagram from Rinker to confirm this. I replaced my deep cycle battery with 2 Group 31 deep cycle batteries. They will fit in the same location if you rotate the house battery 90 degrees and move the start battery a few inches towards the back of the boat. If I know that I am going to be out for a while, I turn down my fridges. They are good at keeping things cold when you are out on a cruise. If you add a few beverages to it, it does take a while longer to cool them down, so make sure the one fridge is well stocked before you leave the dock. I just got my 280 in April. The admiral and I love it. I can't imagine how we managed for so long in a 232cc.
Go Steelers!!!
HI Greg,
Thanks for the advice, I'll definitely be adding a second house battery and replacing both with new units. Do you notice any issues having all that weight on the port side along with the water holding?
I'm no electrician by any means so I'm curious how you wired them up to each other? Any chance I could get a picture of what your battery setup looks like next time you're down at the boat? I'm slowly but surely becoming more mechanically inclined now that I'm a bigger boat owner... it's definitely been a work in progress for a guy who is an IT director by trade.
Derek
When the waste tank is empty, and the fresh water is full, the boat does lean to that side. While underway, it isn't that noticeable.
I wired the batteries just like the top picture that frenchship posted, except that there are only two batteries in the bank rather than four. Same concept, just less batteries. As you can see in the picture, I turned the two house batteries and moved the start battery back a few inches. All of the cables work if you wire it like above.
Go Steelers!!!
Looks ok
Thanks guys, that setup looks great. It seems like there is one extra set of cables in the picture that I wouldn't expect though. Does that have something to do with the generator? It's the extra black and red that are running off the closest most house battery. Looking at Frechship's diagram it only shows two cables leaving the bank of batteries and it looks like you have four total. Again, this is me being non-mechanically inclined so it's probably something obvious I don't know lol.
I just found out I won't be getting my boat until Friday so I won't be able to get down until then to stick my head in the engine compartment to compare.
Derek
The previous owner had the extra battery in a different location, and didn't use heavy enough wire for it. The negative might still be connected. The small red wire that is between the batteries is disconnected. I will have to see where the other red wire goes that is connected. It might be for the bilge pump and stereo memory. The generator wires go to the starting battery. I don't have a generator, so the hot is tucked away next to the wiring harness. The boat is prewired for the generator, so don't be alarmed if you see extra cables hanging.
Go Steelers!!!