Battery Switch Operation

[BoLin]

The continuing saga of Bob's electrical nightmare ...<br /><br />I've got two batteries on my 20' Grady and a Guest battery switch. Switch positions are 1 / Both / 2 / Off. Boat power is an old ('77) 200hp Evinrude O/B.<br /><br />I've read conflicting info on changing switch positions. In the past I've read that once the engine is started you should never change the switch position as it may (probably will) damage the outboard. In the most recent Grady-White newsletter, however, they say that if you start the motor with the switch in the Both position (like I have to do), you should then change the switch position to either 1 or 2. But never to Off as this may damage the motor.<br /><br />Thoughts, suggestions anyone???<br /><br />Thanks,<br />Bob

 

[John McFarlane]

Re: Battery Switch Operation

Leave the switch in the both position for starting and running. <br />This way both batteries are used for starting and are then charged. If you stop for an extended time, like overnight, and need to use power, switch to one or the other. That way there will always be a battery fully charged.<br />Never run the motor with the switch in the off position, or switch when running. The momentary open circuit may be all it takes to fry the diodes in the rectifier.

 

[Richard Petersen]

Re: Battery Switch Operation

I am a believer of either battery should start the motor by it self. You must have on all the time at least 1 battery. Bilge waterpump, lights and everything else. It will be charged constantly. #2 battery is your life guard when #1 gives out in a storm or alone. You should have a dash mounted + and - ammeter and volt meter tied into the selector to check each batteries charge.You will learn by the charge rate when a battery is getting ready to die.---------- Forgot the most important reason. #1 shorts out, you switch to both. Now you have the shorted battery immediatly pulling down the good #2 so low they may not start the engine. 1 battery ONLY at a time for that reason.

 

[John McFarlane]

Re: Battery Switch Operation

Cyclops2, what rubbish. <br />If you only use one battery at a time, how do you keep track of which one you used last time and how do you make sure both batteries are kept at the optimim charge level? What if you forget which battery you used last time out and use the same again? The other battery is left out when it comes to a healthy discharge/recharge cycle.<br />And when was the last time you heard of a battery 'shorting out'? I have been involved in Autoelectrics on cars, trucks and boats for 30 years, and they almost always go open circuit due to vibration and faulty manufacture. And if one did go 'short circuit', it would still probably fry your alternator/stator/rectifier, with the engine/charging circuit seeing no load and trying to charge flat out all the time. That wouldn't happen with two connected as there would still be a significant voltage being seen by the charging circuit. <br />And what if your 'spare' battery went faulty/flat and you didn't find out til you needed it?<br />2 batteries for start and running. Switch to one for loading when the engine is stopped.<br />And don't count on a battery switch being a 'make before break' arrangement. Bad connections and sloppy tolerances happen in the best switches and you could still up with a momentary open circuit that could fry the system.

 

[burp]

Re: Battery Switch Operation

Sorry John, ....but using the "Both" position would have left me stranded this past week. I was saved by the fact that I was able to switch over to battery #2 and fire the engine right up. Had the battery switch been in the "both" position, I would have had 2 discharged batteries.<br /><br />Plus, if both batteries are weak/discharged, the current flow to recharge both batteries could be more than the alternator can supply and result in a damaged/fried alternator.<br /><br />I'll stick with running with the battery switch in the #1 or #2 position and remembering to switch the position while I out to keep both batteries fully charged. I would have a harder time trying to remember if I switched from the "Both" position back to the 1 or 2 position once I got back to the dock. For me the "Both" position will be used only if I have 2 batteries which individually, won't turn over the engine.

 

[dingbat]

Re: Battery Switch Operation

I installed a battery combiner that eliminated the need to worry about any of it. I put the selector on 1 (house battery) when I leave the dock and forget about it. I only use 2 (starting battery) in an emergency or on those cold days that I need a little extra to turn the motor over.

 

[vipzach]

Re: Battery Switch Operation

I agree with dingbat, I do not like having to remember to switch anything when I start or turn off my boat. That is why I like the combiner I put on my boat. There is a company that makes one that you can switch the battery that you start from in case of an emegency. Otherwise it keeps the batteries seperate unless the motor is running and charging.

 

[BoLin]

Re: Battery Switch Operation

Boy - talk about getting 11 opinions from 10 people! I think I'm more confused than before. (But THANKS for all the input.)<br /><br />Bottom line, if I NEED to use both batteries to start, (which was the example Grady-White used) is it or isn't it likely to damage the motor if I then switch to either #1 or #2 as long as I avoid off?<br /><br />Bob

 

[cbcrawford]

Re: Battery Switch Operation

Bottom Line -<br /><br />As long as you have a relatively modern switch, i.e. makes connection before breaks connection, you are fine to switch as long as you avoid off.<br /><br />You will damage your charging system if there is nothing there to charge (OFF).

 

[tengals123]

Re: Battery Switch Operation

this topic always raises the same opinions. Im still in the same delema. I'm going for 2 batteries with a vsr to switch mine over when full.<br /><br /><br />cheers