Association Forum - Trickle charge on Marine Deep cycle

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

Trickle charge on Marine Deep cycle

New Topic

Topic Locked

Printer Friendly

Author

Topic

Bill Sloane
1st Mate

Member Avatar

USA
91 Posts

Initially Posted - 05/25/2004 : 15:42:30

Bought a nice little solar panel to trickle charge my deep cycle marine 12V battery on the boat. The clerk at Schuck's where I bought my battery told me that with deep cycle batteries, they work best if fully discharged before recharging because they get a 'recharge memory' if you keep recharging. I do not have shore power and now I am wondering if I should hook up my solar panel or not.

Thanks,

Bill
C-25 SR/SK No. 496

Edited by - on

JimB517
Past Commodore

Members Avatar

USA
3285 Posts

Response Posted - 05/25/2004 : 16:45:23

That advice is totally bogus. While true for NiCads, its not true for anything else. Your batteries should be kept charged to 13.6 volts (and not higher). Check the water once in a while. It takes a lot longer to charge a lead acid battery from 90% discharged to 100% than it does for 80% discharged to 90%.

Your little solar panel does not have the current to overcharge the batteries so you don't need a regulator. If you had a big bank of panels you would put in a regulator that kept the voltage below 14.1.

The panel will actually develop about 25 volts but without enough current to bring your system voltage much above the target 13.6

Edited by - on

Bill Sloane
1st Mate

Members Avatar

USA
91 Posts

Response Posted - 05/25/2004 : 19:25:13

Thanks Jim.

Edited by - on

oldsalt
Admiral

Members Avatar

USA
578 Posts

Response Posted - 05/25/2004 : 21:29:07

Apparantly that clerk knows nothing about batteries since not only was his advice incorrect, following it would have greatly decreased the useful life of your batteries. All deep cycle batteries have a limited number of deep discharges they can provide before they become unable accept and hold further useful charges. The number of useful cycles depends on among other things; the quality of the batteries ie: Rolls vs K Mart, the sophistication of the charging system and the number of dischages as well as the depth of those discharges. Taking a battery down too far will shorten it's life and keeping it charged whenever possible will extend it.
By the way, for starting large stationary diesels I specify deep discharge Ni Cad rather than lead acid batteries (although to a casual observer they look exactly the same)and they as well, do not have a discharge memory. We use them because since they use potassium hydroxide rather than sulfuric acid as the electrolyte they don't vent hydrogen gas or corrode at the terminals. You top them off with distilled water just like lead acid types. Wet Ni Cads provide a lot of kick and last a long time but are not the equal of lead acid for deep discharge .

Edited by - oldsalt on 05/25/2004 21:33:26

ClamBeach
Master Marine Consultant

Members Avatar

3072 Posts

Response Posted - 05/26/2004 : 00:47:28

Sailnet.com had a pretty decent article on battery charging a day or so ago... worth a read.

Edited by - on

smp817
1st Mate

Members Avatar

USA
30 Posts

Response Posted - 05/26/2004 : 10:51:48

I've never heard of wet Ni-cad batteries. I have an inboard diesel. My wife is always worrying about not being able to start the engine if needed. What is the best set-up for starting and household batteries? I run a stereo and tillerpilot and running lights at night. I'm looking for the best set-up for long usage on household and cranking power on the starting battery. My gauges and lights are connected to both, I think, so they won't shut off if I switch batteries. I do have shore power for charging.
Steve Perry
#5883, "Love & Luck"

Edited by - on

RichardG
Admiral

Members Avatar

USA
990 Posts

Response Posted - 05/26/2004 : 11:57:30

Bill:

I also use a little solar panel to keep one of my batteries topped off. Mine is red, about the size of a shoebox top. Got it at Harbor Freight. I can't remember who recommended it, they said it might be a good idea to put a thin bead of caulk on the seam around the edges, on the seam between the case and the solar panel part, and around where the wire comes out of the case. Those cheap panels are made to be put on the dashboard of a car and aren't designed to be waterproof -- it made sense to me.

Edited by - on

JimB517
Past Commodore

Members Avatar

USA
3285 Posts

Response Posted - 05/26/2004 : 13:12:50

Keep a dedicated battery for starting that diesel. Does it have a manual starting crank?

I'd put in a 2 batery system, battery 1 a starting battery, battery 2 a marine deep cycle (although for your little diesel a marine deep cycle will start it just fine). Probably use Group 27 wet lead acid batteries.

Starting battery is battery 1, deep cycle is battery 2. You have a combiner switch that lets you run the boat on 1, 2 or all. Battery 2 is the "house" battery.

Unless the house battery is run way down, start the motor with the battery switch to "all". Leave the switch on all while motoring. When you shut down, switch to "2" so that nothing is drawing current from battery 1. You are going to keep battery 1 at full charge at all times for emergency starting.

Monitor your voltage with a digital voltmeter. If you drop to 12.5 battery 2 is deeply discharged. If it gets to 12.25 it is basically dead. Don't let it get below 12.25 - that is a full discharge cycle. Either hook up solar panels, run the motor to charge, hook into shore power, or reduce demand.

I can run my boat day sailing for 2 weeks without worrying about charging, and never get below 12.9 volts. That is using stereo, fishfinder, autopilot, knotmeter, VHF, etc.

The cabin lights can run your battery down in 1 night, though. Thats why I have oil lamp and many candles.

If battery 2 is deeply discharged, you can probably switch to "both" and still start the motor. Lots of current is going to be flowing from 1 into 2. That's OK as long as you run the motor long enough to bring the system voltage back up to 13.6 (both batteries are then fully charged).

If the motor won't start on "both", quickly switch back to "1". The problem is that you can't turn the switch from 1 to both while it is running without risking damage to your alternator.

Edited by - on

Bill Sloane
1st Mate

Members Avatar

USA
91 Posts

Response Posted - 05/26/2004 : 15:52:51

Richard,

Just curious what you do with your solar panel when sailing. Do you keep it connected to battery and stow it below? I am thinking of that or making a quick disconnect for the wires so I can put the panel out of the way when underway.

Bill
C-25 SR/SK No. 496

Edited by - on

smp817
1st Mate

Members Avatar

USA
30 Posts

Response Posted - 05/26/2004 : 16:20:18

JimB,
I appreciate the information. I think that is how I am set up, as far as the two batteries and combiner switch. Don't have a manual crank. I'll have to look at the batteries to see what I have in each position for sure.
Steve Perry
#5883

Edited by - on

RichardG
Admiral

Members Avatar

USA
990 Posts

Response Posted - 05/26/2004 : 19:33:27

Bill:

At the dock, my little panel rests on the deck near the bow, with the wires going through the air vent into the v-berth area. My panel already came from the store with a quick disconnect plug about 1' away from the panel. Before I go out, I disconnect the panel and put it in the dockbox, and then disconnect the lead wires from the battery and store them onboard. After I return, I hook it all back up. As the lead wires on my panel terminate with a cigarette lighter plug, I use a short set of jumper wires with aligator clips on each end to hook the "+" and "-" of the cigarette lighter plug to the corresponding battery terminals.

There was a recent discussion with more info on different setups -- [url="http://www.catalina25-250.org/forum/topic.asp?TOPIC_ID=6652"]Electric link[/url]

Edited by - on

AndyR
Deckhand

Members Avatar

Australia
11 Posts

Response Posted - 05/28/2004 : 06:37:54

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Bill Sloane
 Bought a nice little solar panel to trickle charge my deep cycle marine 12V battery on the boat. The clerk at Schuck's where I bought my battery told me that with deep cycle batteries, they work best if fully discharged before recharging because they get a 'recharge memory' if you keep recharging. I do not have shore power and now I am wondering if I should hook up my solar panel or not.

Thanks,

Bill
C-25 SR/SK No. 496

Edited by - on

AndyR
Deckhand

Members Avatar

Australia
11 Posts

Response Posted - 05/28/2004 : 06:40:40

we have a small solar panel on the start battery all summer while the boat is on the moooring. Never had a problem with flat batteries even after leaving it for 5-6 weeks. I think they are a great idea
Andy

Edited by - on

Champipple
Master Marine Consultant

Members Avatar

USA
6855 Posts

Response Posted - 05/28/2004 : 09:22:25

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by JimB517
 
I'd put in a 2 batery system, battery 1 a starting battery, battery 2 a marine deep cycle (although for your little diesel a marine deep cycle will start it just fine). Probably use Group 27 wet lead acid batteries.

Starting battery is battery 1, deep cycle is battery 2. You have a combiner switch that lets you run the boat on 1, 2 or all. Battery 2 is the "house" battery.

<hr height="1" noshade id="quote"></blockquote id="quote">
Jim,
I was always under the impression that if your batteries were not identical in size and makeup, you shouldn't have them combined on the same circuit, i.e. the all switch. Since they might have the capability of depleting and charging differently, you could wind up with one battery pulling from the other?

Please set me straight, because I'd love to have a starting battery and a deep cycle everything else battery.

Also, I heard that you should never switch the battery selector with the motor running as it might bunk up the alternator? is that true?

dw

Edited by - on

ClamBeach
Master Marine Consultant

Members Avatar

3072 Posts

Response Posted - 05/28/2004 : 09:43:19

"you shouldn't have them combined on the same circuit, i.e. the all switch. "

I think you wouldn't want to leave two different types of batteries (like gell-cell/flooded lead/glass mat) in parallel for an extended period of time... or if you had a relatively old battery in with a new one you might pull charge... or have charging current inbalances while you were charging.

On a big boat with large current draws you likely wouldn't want your house batteries in line with your starters during engine fire-up.

"Also, I heard that you should never switch the battery selector with the motor running as it might bunk up the alternator? is that true?"

Probably one of those 'it depends' things (depends on your system components)... I'd avoid potential trouble by not doing it.

Edited by - on

JimB517
Past Commodore

Members Avatar

USA
3285 Posts

Response Posted - 05/28/2004 : 14:57:44

Probably the best thing for our boats is to have 2 identical deep cycle batteries, one for starting and one for house. Use them as I've described. The deep cycle will start our little motors just fine - even the inboard diesel.

It's true that different batteries with different age and charge characteristics will discharge from the stronger into the weaker. However, once your motor is up and running and you are charging I think you would be OK unless one of the batteries has a bad cell. You can measure the specific gravity of each cell with a little tool that looks like a turkey baster. If any cell is significantly lower than the others, throw that battery away.

Cruisers who live for a year on an all electric boat (like my past boat) learn this stuff.

They say if you switch the battery switch through the "off" position it can blow the diodes in your alternator. We don't have alternators, but our outboards do have diodes. However, you can pull the outboard plug without damaging those diodes, so I can't imagine that turning the switch would do any harm. Certainly, my Honda OB has not been damaged by this.

For the C25 with the inboard diesel, I'd say that you should not switch the battery switch with the engine running.

Disconnecting or switching the batteries to off while attempting to charge from shore power can also damage your shore power battery charger (as I just found out).

Edited by - on

Douglas
Master Marine Consultant

Members Avatar

1595 Posts

Response Posted - 05/30/2004 : 11:48:04

I didn't see anything above that talked about amp hour ratting. The size of the battery with regard to its amp hour rate will determine how much and for how long you can draw a load from it. I.E. 80 amp hour = 1 amp for 80 hours or say 4 amps for 20 hours with an ideal battery. If your going to use the battery a lot aim for a higher amp hour ratting.

Edited by - on

sailgal
Captain

Members Avatar

USA
400 Posts

Response Posted - 06/01/2004 : 00:54:15

RichardG... I received as a present two of those Harbor Freight red baby solar panels, one with the cig plug and the other my dad wired with alligator clips. I have two in series identical batteries and a 1 - 2- all switch. I have yet to put these panels into use because I never could get an answer on how to use them properly. First, can you use the cig plug (I have a 12v outlet) and if so would you need to turn the swich from off to all (or 1 or 2 depending on if you choose to charge a specific battery) Second you mentioned your set up with the alligator clips, do you put on the terminal clips of one specific battery , and what would be the proper switch postion while clipped on (off if at dock?) Thanks, it sure would be nice to utilize these panels!

Edited by - sailgal on 06/01/2004 10:52:54

Champipple
Master Marine Consultant

Members Avatar

USA
6855 Posts

Response Posted - 06/01/2004 : 08:18:00

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Disconnecting or switching the batteries to off while attempting to charge from shore power can also damage your shore power battery charger (as I just found out).<hr height="1" noshade id="quote"></blockquote id="quote">

Does your charge run through the battery selector? Ours is direct to the battery and we have the selector on off at all times while charging?? Please give us some more detail.

dw

Edited by - on

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.