Grady White Newsletter

[dwain]

I received the newsletter from Grady White via email and starting reading it. I read the battery section and to my surprise I have been starting the motor incorrectly. My Seafarer has two batteries and I have always started the boat on the "all" position. I have never started the boat using the "1"
Do you guys use just the "1" or "ALL" position when starting? Thanks

 

[SmokyMtnGrady]

Funny, they did not add that little tid bit to the manual. Both Grady dealers I have purchased boat from did go over the boats well with me, but this part of the tour escapes me. After owning a Grady for nearly a decade I finally got this straight. :wink:

 

[dwain]

Hi Bob: Just wanted to clarify. Do you start your engine using just the "1" battery? Do you ever switch to the "Both" and if you do when do you do this? Thanks. Dwain

 

[Gman25]

Its better to use 1 battery at a time. When I had that type of setup I would use the 1 battery one day and on the next trip I would use the 2 battery. If you have a problem with one battery you can always switch to the other to get you home. You may run into a situation where 1 bad battery can drain the other if you have the switch on both.

 

[magicalbill]

Like Gman said..one at a time.

I was always told NEVER to switch from one to the other WHILE the engine is running. I guess serious damage can happen.
The only time I ever used "All" was when the individual batteries wouldn't start the engine. "All" funnels the power of the two batteries together.

 

[capt chris]

Like Gman said..one at a time.

I was always told NEVER to switch from one to the other WHILE the engine is running. I guess serious damage can happen.
The only time I ever used "All" was when the individual batteries wouldn't start the engine. "All" funnels the power of the two batteries together.

Bill,
It's okay to switch from 1 to 2 with the engine running as long as you don't to or through OFF. Grady uses switches that contact both 1 and ALL and ALL and 2 as you switch through the settings. That way there is always contact between the alternator and one or both the batteries. What blows diodes in the alternator is when you're in the OFF position and the current has no battery to flow to. I think the industry term for the switches is "Make before break" switches.

 

[magicalbill]

Thanks Chris.
I probably misinterpreted that info..It has been awhile since I 1st got the scoop on my 2-battery setup.
Obviously I had it on my Seafarer and now on my Gulfstream. it is a great setup and (knock on wood) I have never been stuck with a dead battery since.

 

[seasick]

I always start on one battery . I change which one I use based on the date, ODD battery 1, even date Battery 2. I will sometimes run on BOTH on a return trip to give both batteries a charge. The only time I could see using BOTH to start would be if both were weak and couldn't start the motor but together possibly could.
And yes, most battery switches are Make before Break meaning that going from 1 to BOTH, 1 to BOTH to 2, 2 to BOTH or 2 to bBOTH to 1 all protect the charging system.
Never switch to or pass OFF with a motor running

 

[SmokyMtnGrady]

I usually start it on battery 1. I don't think I have ever moved the switch while the motor was running. I have started on both before. I would add not to do this. Even going between 1 and ALL, there is mommentary position where the circuit is open. It would have to be to isolate the batteries between positions. It may be enough to fry the diodes in the alternator.

This has been one of those things I would get mommentarily confused, thinking I need to ask somebody and then never remembering to do so. This is one of those fundemental things I need a better grasp because for the longest time I had assumptions about the charging system and switch which were not true, like both batteries were being charged regardless of the switch position except for the off position.

 

[Gman25]

Also there is/was a device called a battery combiner where one positive wire goes to each battery and a ground. When the combiner would sense a charge on either side it would open a link and one battery would charge the other. When the engines were off and there was no charge the combiner would close the link and isolate each battery. This way whatever battery you were using it would also charge the other one. Worked well.

 

[J-cubed]

Its better to use 1 battery at a time. When I had that type of setup I would use the 1 battery one day and on the next trip I would use the 2 battery. If you have a problem with one battery you can always switch to the other to get you home. You may run into a situation where 1 bad battery can drain the other if you have the switch on both.

This is the system I use. I rarely use the both setting and never switch batteries when the motor is running. Keep it simple - keep it safe.

 

[Stonewall]

Keep it real simple. Place one battery on 1 and the other on 2 and never touch them.

 

[Gman25]

Keep it real simple. Place one battery on 1 and the other on 2 and never touch them.

Thats the proper way with twin engines and two perko switches(one switch per engine) but its a bit different with one engine, one switch and 2 batteries.

 

[3rd Day]

I too have always used BOTH on my twin engine/battery set-up on this and previous boats. Stonewall offers a good suggestion. I'll give it a try.

 

[dwain]

Thanks guys; I think I will go with the odd and even days. Switch on 1 for even and 2 on odd days and then both on the way in. This should charge the batteries up. Dwain

 

[Doc Stressor]

The only reason that they recommend not using the "both" position except in a low battery emergency is to prevent one bad battery from draining a good one. This can easily happen if you routinely run the boat in the "both" position. Grady recommends running out on #1 and back on #2 in order to keep both batteries charged.

There are better ways to keep both batteries fully charged. Yamaha engines from 150 hp or over have built in fused battery isolators since about 2004. All you need to do is to purchase the cable that plugs into the rectifier on the engine and connects to the positive post of the #2 battery. When you run with the switch in the #1 position, both batteries will be charged until full. But if one battery goes bad, the isolator prevents it from draining the other battery. This setup lets you use the #1 battery for starting and the #2 battery for house electronics. You never have to worry about changing the switch position except for an emergency. The cable costs about $70 from a Yamaha dealer.

The battery combiner suggested above is an even better solution. In addition to preventing a bad battery from draining the other one, it sense the voltage of each battery and will charge either when its voltage drops below 12.8 V. They are really designed for boats with banks or batteries for trolling motors or heavy house current usage.

You can read about how they work here:

http://www.yandina.com/acrobats/C70Manual.pdf

I'd bet that Grady and other manufacturers start installing these as standard equipment pretty soon.

 

[richie rich]

Doc, can you further explain how one battery will drain the other if one goes bad? Unless it's shorting to ground, how will the bad battery discharge the remaining good one? Wouldn't you just continue run on the one battery thats good and the charging system continually replenish the good battery while doing nothing to the bad one?[/quote]

 

[Doc Stressor]

Sure. If you develop a bad cell in one of the batteries or just sultanate the plates, the potential will drop below 12 V. If you have the switch in the "both" position and the engine is turned off or running at idle speed, current will flow for the good battery with the higher potential to the bad battery where the energy will be lost as heat.

Modern computer controlled engines draw about 10 amps or more while they are running. The alternator puts out less than that at idle or slow trolling speeds. So the engine draws the difference from the battery bank. Under those conditions, a bad battery will draw from the good one unless you have a battery isolator.

If an alternator fails, the engine will draw down both batteries. You won't notice a problem until the amp hr storage capacity of the batteries is approached. If both batteries are connected, once the engine starts to misfire, you are screwed. With an isolator or a battery combiner, the second battery will be protected. After switching to the good battery, you can run for up to an hour off of the battery (depending on the reserve capacity rating and battery condition) despite the dead alternator.

If an alternator fails, the tachometer stops working. You should head for shore immediately if that ever happens. Radio your situation to the CG or other responsible party in case you batteries fail before you get back.

 

[richie rich]

Thanks for the insight....I was always under the impression that once a battery goes bad, ie below its proper potential and won't give your equipment the right voltage, then it also won't take a charge either from a charger, engine alternator and the battery next door.......good info.

 

[NOTHING ELSE MATTERS]

Keep it real simple. Place one battery on 1 and the other on 2 and never touch them.

This is also what Grady recomends. Battery switches point away from each other.
But this only for twin engines.