marine battery switch help please

[flying kurbmaster]

I bought this second hand marine battery switch, no instructions, It has&nbsp;four settings Battery 1, both , Battery 2 and off. I&nbsp;currantly have a good starting battery and was planning on keeping it until it dies. I will be buying a new 12 volt deep cycle as there is a spot and brackets&nbsp;for this under the hood.&nbsp;there are three large connections at the back of my switch 1, 2 and feeder. I assume I hook up the positives of these batteries to these connections and the altenator to the&nbsp;feeder part. My house&nbsp; lights and&nbsp;outlets are connected to the deep cycle. What puzzles me is&nbsp;there are two other small connection at the back of the switch and it says field on them what is this for ( accesories???)&nbsp;I am only guessing on how to connect this can someone shed some light on what I should be doing,&nbsp;cheers. I used to have a similar switch on my boat and I could use one battery at&nbsp;anchor switch to the other to start and have one or both charge while I was motoring. I also plan on getting one of those 80 watt suitcase solar kits&nbsp; to keep the house going when parked up for longer periods. &nbsp;I read somewhere that it was not a good idea to have different types of batteries&nbsp;hooked up together,,,,???/<img class="emoticon bbc_img" src="/images/boards/smilies/confused.gif"><img class="emoticon bbc_img" src="/images/boards/smilies/confused.gif">

 

[highdesertranger]

I don't know what switch you have a pic would help.&nbsp; but it sounds like you are talking about a selector switch.&nbsp; is it red with a black dial that you turn to select your battery, &nbsp;if it is it's a perko (sp?).&nbsp; these are for selecting what battery you want to run.&nbsp; connect battery 1 to post 1 and battery 2 to post 2 and the feed goes to the load like your 12v accessories.&nbsp; some can handle starting loads some can't.&nbsp; not sure about the field terminals I would only be guessing.&nbsp; highdesertranger

 

[flying kurbmaster]

it is a Guest switch, I just googled it and found some info, the field part goes to the regulator, it means you can not only switch from battery to battery while running but you can also switch to the off position when vehicle is running without damaging your altenator. I managed to download the wiring diagram, battery one to positive one, battery two positive two, feed is the starter wire and whatever&nbsp;other wires go to the&nbsp;positive on existing battery. I will give that a&nbsp; shot and see&nbsp;how I do. thanks,&nbsp;

 

[wrcsixeight]

The two smaller terminals are for the alternator field wires. &nbsp;This disconnects the field wires if the switch is turned to off with the engine running, saving the alternator from a load dump, diode frying scenario.<br><br>I Did not utilize this alternator field disconnect feature, and just make sure not to turn the switch to off with the engine running, but this is not idiot proof. &nbsp;Beware of this when allowing idiots near the switch if you also do not utilize this feature.<br><br>Only the (+) cables run through the other terminals.<br>Run a separate cable from terminal 1 to the engine battery<br>Run a separate cable from terminal 2 to the house battery<br>Run a separate cable from the ignition terminal to the original (+) engine battery connector which will no longer be hooked to the battery &nbsp;Wrap with red electrical tape.<br><br>Doing it this way, one can later easily remove the cable and return the charging system to how it came out of the factory, and move system to another vehicle..<br><br>&nbsp;In addition, You can also run a cable directly to the Alternator (+) Stud to ignition stud to greatly increase the current making it to the house battery. &nbsp;Fuse it to protect the cabling and take extra steps to protect from chafing however you run this wire. &nbsp;This circuit will parallel the stock alternator charging (+) path but be much &nbsp;shorter(depending on switch placement) allowing faster recharges.<br><br>Make sure the battery to frame/ engine grounds are nice and fat too.<br><br>The fatter the cabling, the better recharging performance until the voltage regulator reverts to a lower allowable voltage, or until the house battery reaches 80% state of charge.<br><br>The fatter the cabling the more amps the alternator can be asked to produce, creating more heat, shortening its life.<br><br>I Love the manual switch. &nbsp;I use the connectors on the back of it as Buss studs, taking power for my inverter and Fuse block from the house battery stud.

 

[flying kurbmaster]

thanks for that, I was thinking of not bothering with the field connection either, unless it is dead easy to&nbsp;figure out&nbsp;and just making sure there are no idiots about...

 

[wrcsixeight]

I know Dodge uses external voltage regulation, but many Chevy and I have no Idea about Ford use an internally &nbsp;voltage regulated alternator so making use of the field disconnect feature is not even possible.<br><br>I make sure to start the engine on just the engine battery, and then after 30 seconds or so I will switch to both, and the engine note changes as the alternator goes from producing 12 amps to 60+(each 25 alternator amps sucks one engine HP)<br><br>If the house batteries are really low, I move the switch to 2, so that the engine battery is removed from the circuit. &nbsp;This not only allows more amps into the thirsty house batteries, but also allows the voltage regulator(internal to my engine computer) to allow 14.5 volts to be held for longer periods of time, before reverting back to 13.7. &nbsp;Not many amps are required to hold 13.7, compared to 14.5, so charging really slows down. &nbsp;If sunny, at some point my solar would contribute more to the house batteries than the alternator as my solar charge controller is set to hold 14.5 for 90 minutes.<br><br>I don't like to start the engine using the house batteries though and turn the switch back to 1. &nbsp;The electrical surge from the starter could damage My fridge's electronic compressor controller.<br><br>This is the biggest PITA with using a manual switch in my Van, and often if doing a lot of short trips, I leave the house batteries out of the loop and just let the solar do its job.

 

[Optimistic Paranoid]

I believe most modern cars and trucks have done away entirely with separate voltage regulators.

These days, regulating the alternator voltage is just one of the many things the engine computer does.

Regards
John