Association Forum - Fighting dead batteries in the off-season

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

Catalina 25 Specific Forum

Fighting dead batteries in the off-season

New Topic

Topic Locked

Printer Friendly

Author

Topic

Page: of 2

ClamBeach
Master Marine Consultant

Members Avatar

3072 Posts

Response Posted - 12/02/2008 : 09:09:38

"I do not see how you will ever blow those 60 amp fuses."

The rating of the fuse should be less than the rated current for the wire in the run.
The 8ga copper wires are rated for about 40 amps.

I'd size those primary fuses at 30 amps.

At each change in wire size (like downstream from the distribution panel) the fuses are downsized to protect the wiring... i.e. a 12 ga wire gets a smaller fuse.

Edited by - on

Dave Bristle
Master Marine Consultant

Members Avatar

Djibouti
10005 Posts

Response Posted - 12/02/2008 : 09:27:12

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Prospector
 ...the charger that was draining the batteries.<hr height="1" noshade id="quote"></blockquote id="quote">Sounds like the solar panel has no diode to prevent that. If it doesn't, the panel charges in sunlight and discharges in darkness.

Your battery switch should be wired so either battery can be used and charged alone, or both together. When in the Off position, the battery positives are disconnected from each other. I recommend a book like Don Casey's Sailboat Electrics Simplified. It'll show you a couple of "correct" ways to wire the switch, neither of which looks like what you've done (if I'm reading yours correctly).

Edited by - Dave Bristle on 12/02/2008 09:33:41

Prospector
Master Marine Consultant

Members Avatar

Canada
3159 Posts

Response Posted - 12/02/2008 : 09:43:38

I agree about the fuse size and was wondering that even as I hooked it up. I'll hae to see if I can get a 30 or 40 amp fuse in the fuseholders.

Dave - I did have a charge controller on th esolar panel, and I don't think it was discharging at night, although that is a good thought. I have not had the solar panel hooked to the batteries since pulling the boat for the winter.

I am thinking that I will get a handful of bus bars. One will be the negative "manifold" and I will run all the grounds to it, and then run the negative battery leads to it as well. Should ground everything. I may still do a direct run to th ebattery thought for th estarter on the OB since it is the single highest load that I can think of being put on the 12V system.

Another bus bar will be for the chargers. on it I will run the leads to the 110 charger, the solar, and the alternator. Then I can put a charge controller like this one: [url="http://www.canadiantire.ca/browse/product_detail.jsp;jsessionid=J1WR5pKxjznljkGDcTdN04Fj9bHvqfLNJbVnf4HY2NyZPL8xtS9f!715834817?postal=L0E+1R0&PRODUCT%3C%3Eprd_id=845524443276257&FOLDER%3C%3Efolder_id=1408474396673605&bmForm=form_set_price_list&bmFormID=1228232242133&bmUID=1228232242133&bmHash=18dc2586ab93e6a37b99af6de420abaf10503080"]Cdn Tire Charge Controller[/url] or this one: [url="http://www.canadiantire.ca/browse/product_detail.jsp?PRODUCT%3C%3Eprd_id=845524443290319&FOLDER%3C%3Efolder_id=1408474396673605&bmUID=1228232344422&deptid=1408474396672395&ctgrid=1408474396672406&subctgrid=1408474396673605"]Better Charge Controller[/url] between the "chargers bus bar" and the "positives bus bar".

I should draw this out or it will continue to not make sense. In any case, I think I may have found a solution.

Edited by - on

OLarryR
Master Marine Consultant

Members Avatar

USA
3473 Posts

Response Posted - 12/02/2008 : 12:59:20

If you have a controller on the solar panel then it is probably not discharging at night. Besides controlling the output of the panel so that the batteries don't cook, solar controllers prevent the discharge back thru the panel.

Anyway...it sounds like you are onto recovery from your original battery issue and now onto making an improvement !

Edited by - on

swanny
Deckhand

Members Avatar

USA
24 Posts

Response Posted - 12/24/2008 : 17:28:05

Hope this post finds your batteries charged.
Looks like this thread has been quiet for a while, but I found it interesting as I just finished a rewire to isolate my batteries from each other.

I'm guessing that the "B" on the Battery Sswitch isn't Both, but the output of the switch that could be either 1-2-Both-Off. If this is the case, there is a danger of damage to the charging system of some outboards if you happen to run the outboard with the switch in the "Off" position. From what I have read the voltage output could spike, and without a load to absorb it (the battery) the E spike could cause damage to the outboard charging sys.

I'm using a 2-bank charger, and my Gnd Bus Bar and Battery Isolator are mounted on the back (aft) side of the Battery box. Charger is in same general area. One downside to using an isolator in this configuration is lower amperage output from the outboard to each battery (3A). If I switched the outboard manually I could get the full 6A output to one battery....thought about putting in a switch for this purpose....just one more hole.
Here is how I wired mine up:

Edited by - on

Sloop Smitten
Master Marine Consultant

Members Avatar

USA
1181 Posts

Response Posted - 12/26/2008 : 10:29:34

Swanny,
That is a great electrical diagram and I particular like the way you have all the positive leads to your batteries fused appropriately. I am going to use it to make some changes to my boat and laminate a copy to keep on board.
Great work!

Edited by - on

Stu Jackson C34
Admiral

Members Avatar

844 Posts

Response Posted - 12/27/2008 : 12:18:31

Interesting discussion continues. See how much fun putting a wiring diagram together can be?

1. Please remember: Many people get "confused" with the 1-2-B switch. There are only three points of wiring connection to the switch: 1, 2, and common (B). There are four POSITIONS to the switch, 1,2, B and off. However, OFF is NOT a wiring point of connection, it is a switch position.

2. Battery isolators draw anywhere from 0.6 to 1.0 volts. They are pretty old technology. Employing them on the output of the engine alternator to charge the batteries when underway will result in undercharging of the batteries. I recommend removing the isolator and simply using a switch. OTOH, if you are not depending on the engine to charge very much, your shore power charger will do the work if you plug in regularly.

Edited by - on

swanny
Deckhand

Members Avatar

USA
24 Posts

Response Posted - 12/28/2008 : 18:42:23

Thanks Stu....that is a good point!

There is a voltage drop across the isolator. There are isolators that drop next to no votage, so they say(http://www.perfectswitch.com/isolator.htm) couldn't find prices on the website, hmmmm...

As a side note, I wouldn't recommend anybody rely on the outboard to fully charge their batteries, most don't have the kind of output you want to keep them up. If the typical output of an outboard is in the 4-6 Amp range it would take a long time to charge a 50% discharged battery. Besides....it's a sailboat, who wants the engine running that long ;)

If you do put in a switch, you should try to find one that it is a 1-2 switch...best to not have an "off" or "both" for this application...kinda defeats the purpose, and make sure it can handle the current flow.

For those interested I will try check my actual voltage drop tomorrow and get back with my results.

Edited by - on

Dave Bristle
Master Marine Consultant

Members Avatar

Djibouti
10005 Posts

Response Posted - 12/28/2008 : 20:36:58

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by swanny
 If you do put in a switch, you should try to find one that it is a 1-2 switch...best to not have an "off" or "both" for this application...kinda defeats the purpose...<hr height="1" noshade id="quote"></blockquote id="quote">

1 is just 1, 2 is just 2, All is both, Off is neither... What purpose is defeated?

My Honda 8 put out up to 12 amps--6 amps around idle... I never charged my battery any other way during the season, but indeed I didn't have a stereo and subwoofer, or other amp-hogs--just lights, instruments, GPS, engine starter, and an occasional cell phone charge. (My current Honda puts out 60-90 amps.

)

Edited by - Dave Bristle on 12/28/2008 20:41:28

swanny
Deckhand

Members Avatar

USA
24 Posts

Response Posted - 12/29/2008 : 01:30:25

Sorry I was unclear Dave, I was referring to the purpose behind installing an isolator so that the batteries would be isolated and the engine not inadvertently run with the switch off and no load for the charging circuitry on the outboard.

I have a plug in cooler and an autopilot....guzzlers!...oh and the 120W amp for the stereo....no subwoofer though ;)
Sounds like the Honda 8 has the Nissan 9.8 spanked on the output! From what I've read on this Nissan its 6A peak.
60-90 Amps?!? What kind of Honda is that?

Edited by - on

swanny
Deckhand

Members Avatar

USA
24 Posts

Response Posted - 01/20/2009 : 23:50:41

I finally read the voltage on the batteries last night after a pleasant but chilly weekend trip to Anacortes.
Battery standing voltage: 12.47VDC (engine off after full day of Autpilot, Stereo, DVD player under sail)
Voltage on Outboard Output @3700RPM: 13.76VDC (Read on the input to the isolator)
Voltage on Batt 1 & 2 @3700 RPM: 13.01VDC (Read on the respective Isolator Outputs)

It was a cold Dec 29th launch, but worth the effort! ;)

Edited by - on

Page: of 2

Topic

New Topic

Topic Locked

Printer Friendly

Jump To:

Association Forum

Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.