Thanks. It has the OEM two-battery setup which seems to be just a switch (no isolator (but maybe I'm wrong and there's an isolator somewhere--haven't found seen one though and I've poked around a good bit). Manual says to switch to two batteries when running, one when anchored so as not to accidentally drain them both, then use the other for starting (or both if both are charged). Do you think I could just use a big diode or some sort of simple isolator for the bilge pump circuits and leave the rest alone? I'd rather not get into adding an isolator for the whole system if I don't need to. Both are "starting" batteries--not setup like an RV or cruiser boat with a deep cycle house battery and a starting battery.
You may or may not have an isolator, but if you see a big finned heat sunk module in the charging line from the alternator, that'll be it. If they parallel the two batteries without one, you can run into all kinds of problems down the line. With the isolator, you charge both batteries but only use one at a time. It's not that expensive. If you used diodes as an isolator for the bilge pumps, you'd need two, one for each battery. And they'd have to be heat sunk and have an amp rating greater than the total 2 pump draw, just for safety.
Cool thanks. Haven't seen an isolator anywhere, but I can run off just one battery and not drain the other by using the switch. I've seen RV isolators before so know generally what they look like. Pretty sure the boat doesn't have one, but could be wrong. I know the manual suggests that only the battery(s) selected with the switch will be charged when running. I'll poke around some more next time I'm off work in daylight hours to verify whether it's got an isolator or not. If not I might try to stick to a wiring scheme that doesn't require one.
If you add an isolator you will never get a full charge into the batteries, use of an isolator generally causes you to lose about 1v which is huge in a 12v system. We learned that 15 years ago when we couldn't get enough charge into a (new) 8D battery to run the electronics all day while sitting on the hook, chumming for bluefin. Not much harder (if any) to install and much more effective is a COMBINER, just a voltage triggered relay. You wire the combiner to the two batteries and once it senses more that 12.8v on battery 1 (usually your starting battery) it connects to battery 2 and charges it, it will also disconect the battery 2 when it senses a voltage below 12.8 (some of the expensive ones are adjustable, haven't used them) saving your starting battery. There are a couple of options on the rest of the wiring. On my last 3 boats I separated out my wiring so that battery 1 just supplied the engine and battery 2 supplied everything else. I kept the battery selector switch so that the engine could be started/run on either or both batteries and added a similar on/off switch between battery 2 and everything else. Under your current system (full manual) you have to remember to keep switching the selector back and forth to get both batteries charged and when you forget, you can run both down while hanging out with the radio, etc. running. I have used combiners from West Marine on two of my boats and two others, for my latest boat I got one from Blue Seas. I think that you can get more info and wiring diagrams on either of their websites. Bruce
Automatic switch on bilge pump is OK, as long as you add a way to manually bypass it for when, not if, when it fails. 2000 gph is not with the resistance of the hoses, and fitting. 1000 gph maybe in the boat. So you are wise to put them in. That 500 would have been hard pressed to hit 250 in the boat. If things go bad, you can not have too much bilge pump. 500 in that size boat is way too small. Heck I had 500 in a bass boat with a 250 back up, got caught in a sudden storm and it was not enough. I was close to the harbor, and in a 10 minute low speed run, too rough to plane I had many gallons of excess water on board. The floor was awash. took a long time to pump out pulled up on on old tire and tied up, it had to pump for 30 minutes before I could get on the trailer and then drain on the ramp for another 10 minutes with the plug out before I could pull up the ramp. Drained at my trailer for a while after that. I put in a 1000 GPH the next week, and never ever needed it again. I bet I was close to half full. Of course bass boats do not have much free board. Rod
Given that it's getting down to freezing here and that I use to be in Clearwater every week, this picture is making me wish I had a place down there.
True to an extent. But it really matters where the "sense" wire is located at in the charging system. If the wire is attached to the alternator output then you will have low charge voltage as the alternator will be crippled at the output post. But if the sense wire is at the battery it will raise the alternator output voltage to cover the voltage drop through the isolator.
It also doesn't help if most of the day the engine is idling because the boat's used for fishing. It's far better to have a pair of group 31 deep cycle truck batteries and then plug the boat in to charge on the lift overnight.
Late to the party here, but... My folks had the same model, except it was an '05 or '06. Colbalt builds some very nice boats. They offered it to me at a ridiculously low price after my dad got sick in '09, but jobs were still being lost all over at the time so I had to decline, and I regret it every day there's no snow on the ground. Still trying to find the "right" boat three years later. Enjoy yours!
Ducnut--come visit when it gets too cold up there Spikehead, good luck finding a boat that suits you! I'll research the combiner and isolator systems more. Generally, I'm not super interested in changing the whole battery system--just want to hook up the bilge pumps in the most reliable, redundant, method possible. Ragtop, I agree completely. 500gph wasn't enough on my 550cc jet ski (of course it did tend to get sub'd). For auto switches, I've got two of these ready to install, supposed to be super reliable. Still like the idea of a manual override. http://www.waterwitchinc.com/new/SiteElements/Pages/SecondaryPages/Products/BilgeSwitches.html
Last weekend I went out and on a whim wired the "silent choice" exhaust wide open (loud-straight out the back through 4" corsa pipes). Massive improvement in performance. Hitting the throttle from a dead stop gives a nearly-instant 4,000 rpm and then it climbed to 5,000 rpm and 53mph in ~1.5' chop and a ~6mph headwind. Boat was light though--2 people, minimal gear, and probably 15 gallons of fuel onboard. Added another 40 gallons (after burning up most of the 15) and 4 guys total and went back out. Ran about 48-49mph at about 4900 rpm. A bit more chop and wind, also 2 of the guys were sitting in the bow and I couldn't trim the bow up as much as usual. I think it'd have done a solid 50mph with them in the back... So very happy with performance now! Still need to sort the bilge pumps and all that stuff, probably will be working on that on Thanksgiving.
I don't know jack about sailboats or sailing, but I've always thought a 40' Nautor Swan would be just spiffy to own.
FWIW I've learned that having two identical batteries lasts longer than if they are at all different. When maintaining boats I subscribe to the "Small boat, large ocean" theory.
As an update, I did sort out the bilge pumps last fall with 2x 2000gph pumps and 2x of these http://www.waterwitchinc.com/new/SiteElements/Pages/SecondaryPages/Products/BilgeSwitches.html with independent power (each wired to a seperate battery--very simple. Only downside is if one battery dies that BP is out of commission, but since there's two I'm ok with that). They've been flawless so far. These switches with no moving parts seem awesome, highly recommend them. I also replaced the IAC motor (it's idled a little too high since I bought it) and that fixed the idle completely. Runs ~900rpm cold then drops to 600rpm hot just like it's supposed to. Holds those whether in or out of gear. Odd thing is the computer showed the IAC motor stepping like it should, but obviously it wasn't. Docking is much easier at 600rpm than it was at ~1k rpm. The batteries that came in the boat finally died yesterday and I picked up diehard platinum batteries to replace them. Will bolt them in this evening. They are supposed to be the same as odyssey batteries (AGM) so hopefully will hold up well and spin the BBC over nicely. The old batteries never were able to start it on just one battery (once I got them out I found that they were group 24 West Marine batteries with 625cca--Merc manual says 650 min to spin the motor over). The new batteries are group 34 which is about the same size as a 24 (that way I don't have to get new battery holders and all that) but have 880cca each. I thought about going to 31s but but really didn't want to re-do the battery holdown setup and wasn't crazy about the extra ~30lbs they'd add to the back of the boat. I also mounted an on-board battery charger some months ago with two independent outputs. Seems quite spiffy and to be working well. And just for Ducnut, here's a pic from last December
Yeah, that's cruel. A friend's son just got back from FL. He applied for, and got, a transfer and his partner already got a job, down there. They're moving down, within the month. I'm jealous.
Haha, nope, still loving it Ducnut, when you come to FL to visit swing by Tampa for a beer and boatride.
If ducnut doesnt take the offer, I will. I'll be down for Christmas. Currently shopping for a boat just like that. Silly COE marina restrictions dictate it's got to be an open bow, and under 28 feet. You got the three foot itis itch yet?