Battery Switch - Used for Charging Batteries?

[doc-holiday]

Hey Guys,

Quick question to those of you who have some experiance with the use of battery switches, such as the one below.

http://www.overtons.com/assets/images/products/large/31620_L1.jpg


I am looking to have two batteries on board this summer. One will power all of my main items, such as lights, bilge ect. My other will power just items that are not always needed, like my trolling motor, CD player ect. My question is, can I wire up two batteries to this switch, and use it to switch between which battery I will start my motor up with? I would like to select either battery and charge it while being out on the water when my motor is running. Does an idea like this even make sense? I can try to draw up something and post it as well with like what I was thinking. Thanks for the help,


Doc

 

[Beefer]

Re: Battery Switch - Used for Charging Batteries?

I think my answer will be correct, but if it isn't, don't worry, many will let us know I was wrong.

Typically, when a 2 battery system is connected through a switch, one battery (starting battery) (BAT1) is for starting only, and the other battery (house battery) (BAT2), is for all other items. When you start the engine, you select BAT1, then switch to ALL. This will charge both batteries, and use both batteries while running. When you get to your destination, you then select BAT2 to run your desired electricals on. BAT2 should be a deep-cycle battery, and BAT1 should be a starting battery.

This is how I plan to do mine as soon as I can figure out a spot to mount my danged battery switch, but that's another thread.

 

[Beefer]

Re: Battery Switch - Used for Charging Batteries?

Oh, and you can get the battery switch right here at iboats, and support the forums in doing so. Click on the Boat Parts & Accessories link at the top of this page, and there ya go!

 

[fish_on_the_deck]

Re: Battery Switch - Used for Charging Batteries?

Yes, that switch will work... so will any other 1/2/both/off battery switch.

agree with beefeter, except be careful switching between batteries while your motor is running, if you dont have a "maek before break" switch it can seriously damage your outboard.

 

[Silvertip]

Re: Battery Switch - Used for Charging Batteries?

Once again, there is a misconception about what the switch does for you. When using a battery switch NOTHING is dedicated to EITHER battery. EVERYTHING on the boat gets fed by the COM terminal on the switch. If the switch is set to BAT 1, the engine starts on BAT 1 and BAT 1 powers all the accessories. Patience here - read on!! If you select BAT 2, it will start the engine and power all accessories. If you select BOTH, both batteries start the engine and power all accessories. But you say -- I don't want to run a battery down. You won't if you use the switch as it is intended. Start the engine on BAT 1 (starting battery by default) and then switch to BAT 2 or just leave the thing on BAT 2 for starting and cruising to your next destination. Both batteries will be charging and powering things during this time. When you anchor to listen to tunes or whatever you do when anchored, switch to BAT 2. This disconnects the start battery (BAT 1) so you don't run it down. When ready to go, switch back to BOTH and be on your way. The switch works both way -- it powers from and charges whatever battery or batteries you have selected. You DO NOT need to wire things to dedicated batteries. That's what the switch is for. The only exceptions to this dedication discussion is that the trolling motor (if used) and the bilge pump should be wired directly to the battery. This allows automatic bilge pumps to run when the switch is OFF. It also allows operation of the trolling motor regardless what switch position is selected.

 

[G-Money-Sunbird]

Re: Battery Switch - Used for Charging Batteries?

Once again, there is a misconception about what the switch does for you. When using a battery switch NOTHING is dedicated to EITHER battery. EVERYTHING on the boat gets fed by the COM terminal on the switch. If the switch is set to BAT 1, the engine starts on BAT 1 and BAT 1 powers all the accessories. Patience here - read on!! If you select BAT 2, it will start the engine and power all accessories. If you select BOTH, both batteries start the engine and power all accessories. But you say -- I don't want to run a battery down. You won't if you use the switch as it is intended. Start the engine on BAT 1 (starting battery by default) and then switch to BAT 2 or just leave the thing on BAT 2 for starting and cruising to your next destination. Both batteries will be charging and powering things during this time. When you anchor to listen to tunes or whatever you do when anchored, switch to BAT 2. This disconnects the start battery (BAT 1) so you don't run it down. When ready to go, switch back to BOTH and be on your way. The switch works both way -- it powers from and charges whatever battery or batteries you have selected. You DO NOT need to wire things to dedicated batteries. That's what the switch is for. The only exceptions to this dedication discussion is that the trolling motor (if used) and the bilge pump should be wired directly to the battery. This allows automatic bilge pumps to run when the switch is OFF. It also allows operation of the trolling motor regardless what switch position is selected.

Silvertip, Thanks for this answer.....this is the clearest explaination of using a 2Bat/1Switch set up that I have seen on this forum. Been gathering all that I needed to put this option into my Sunbird and I was just waiting till I found a clear wording of the how and why. This is it. Thanks again.....Will tackle this project this weekend as well as installing my TM.

 

[doc-holiday]

Re: Battery Switch - Used for Charging Batteries?

Thanks for the infor Silver,

I read a lot more posts about this topic after I posted mine, so I am sorry for making you type out a response once more! Thats how I figured the switch worked, but I just wanted to make sure from someone who has used them before. Thanks again for your help, my boat will be a lot better on the water come spring!

 

[jmarty10]

Re: Battery Switch - Used for Charging Batteries?

Awesome thread! I'm saving this one to my favorites as I'm going to wire a switch in over the winter for a dual battery setup. Quick point of clarification on charging. If I stop the motor, anchor and listen to radio on bat 2 and then switch back to bat 1 and start motor, will bat 2 charge up again? or, does it have to be set to both for both batteries to charge?

 

[doc-holiday]

Re: Battery Switch - Used for Charging Batteries?

Marty, the switch will have to be set to "Both" or whatever setting the switch has on it that connects both batteries. You still may be able to even start your motor on Bat 2 however and just charge that alone on the Bat 2 setting. I was worried that I would ruin something by running the switch on the "Both" setting, but after reading from what Silver wrote, everything I thought about the switch is true, so you should be all set.

 

[Mark42]

Re: Battery Switch - Used for Charging Batteries?

....... Start the engine on BAT 1 (starting battery by default) and then switch to BAT 2 or just leave the thing on BAT 2 for starting and cruising to your next destination. Both batteries will be charging and powering things during this time. ....

I do believe this is incorrect. Only the battery selected will charge. If the switch is on Bat1, it will use battery 1, and battery 2 is isolated from the system. Same when selecting Bat2; battery 1 is isolated from the system. In order to charge both batteries while underway, the switch must be set to "Both".

 

[Silvertip]

Re: Battery Switch - Used for Charging Batteries?

If you read the post carefully, I said that you can start the engine on BAT 1 OR leave the switch on BOTH. On the BOTH setting both batteries WILL charge. Obviously if left on BAT 1 only BAT 1 will charge.

 

[Greg Mrozinski]

Re: Battery Switch - Used for Charging Batteries?

Doc, Jmarty and G-Money,

Please keep in mind that the charging coil on outboards and OEM alternaters on I/Os typically do not have enough output to fully charge a weak battery. Putting around or sitting with the engines idling will not give much charge to your battery(ies). You would have to run your engine(s) at cruising rpms over an extended period of time (hours) to provide sufficient charging to a weak battery (especially a deep cycle one). So always start off with fully charged batteries.

 

[Mark42]

Re: Battery Switch - Used for Charging Batteries?

If you read the post carefully, I said that you can start the engine on BAT 1 OR leave the switch on BOTH. On the BOTH setting both batteries WILL charge. Obviously if left on BAT 1 only BAT 1 will charge.

Ok, I'll let it go this time... But next time you pay the consequences for making my brain hurt trying to understand this stuff!!!!

 

[G-Money-Sunbird]

Re: Battery Switch - Used for Charging Batteries?

Doc, Jmarty and G-Money,

Please keep in mind that the charging coil on outboards and OEM alternaters on I/Os typically do not have enough output to fully charge a weak battery. Putting around or sitting with the engines idling will not give much charge to your battery(ies). You would have to run your engine(s) at cruising rpms over an extended period of time (hours) to provide sufficient charging to a weak battery (especially a deep cycle one). So always start off with fully charged batteries.

Understand 100% Greg. Don't plan to use my alt to fully charge batteries, just to put a little juice on them while on the water and then plug them all up when I get home.

Thanks

 

[Outsider]

Re: Battery Switch - Used for Charging Batteries?

Silvertip, I believe the confusion is because of the lengthy verbiage between If you select BOTH and Both batteries will be charging.

Doc, way too many get hung up on 'starting' and 'house' batteries. Don't know how heavy an electrical load you have, but many boaters consider the second battery a safety item to be left fully charged unless/until needed. On my boat, using BOTH is an emergency procedure used once in 21 years and would signal the start of my return trip to the dock. Both batteries are deep cycle and either starts my 225 Honda just fine. I will switch up which battery is primary, but not on the same day ...

 

[Twin_Vee]

Re: Battery Switch - Used for Charging Batteries?

so i think i have a good grasp on the switch thing (thanks to the previous posters!!!)... but something i haven't seen discussed is placement / distance of the batteries.

my primary battery is in the rear next to the engine but my second battery is in the bow (trolling motor, anchor winch, some lighting etc)...

it's about 12 feet in a straight line but of course would be more like 15 feet twisting it's way from battery to battery...

can i still use the the switch and charging scheme listing previously??

thanks!!!

 

[fish_on_the_deck]

Re: Battery Switch - Used for Charging Batteries?

long distance will charge fine... its when you go to try and start your motor with a battery connected via a long cable that you could have issues if your cables are not sized properly.

more current = more voltage drop with fixed resistance.