charging 3 way switch

[ferrism]

I have a problem and I hope someone has the solution. I have a boat that has three 12 volt batteries. One battery is for the outboard motor and is of no concern here as it is on its own circuit. The other two batteries were for the 12 volt trolling motor (hooked up in parallel.) I have a promatic 30-3 charger that charged all three batteries at the same time. Everything worked just fine. Then, the 12 volt trolling motor went kaput and I upgraded to a 24 volt trolling motor and rewired the batteries to produce the required 24 volts. Now I cannot use the charger to charge the two trolling batteries at the same time and I don't want to invest in a 24 volt charging system. So, what I have in mind to do is to find a switch that I can run the positive cable from one battery to a lug on a switch, run the positive lead from the charger to a 2nd lug on the switch and then the third lug on the switch will go back to the battery. This way I don't have to remove the positive lead on the battery each time I want to charge it. Can you help me find that switch, or in the alternative, explain how I can charge all three batteries at the same time?? Thanks, Ferris

 

[Boatist]

Re: charging 3 way switch

It is real simple. You can not charge all three bateries at the same time with a 12 volt battery charger.

 

[levittownnick]

Re: charging 3 way switch

Would you consider using multiple battery chargers at the same time?

 

[Silvertip]

Re: charging 3 way switch

The Promatic 30-3 is a three bank charger (three separate sets of 12V outputs and you can indeed charge all three batteries. Three bank chargers are three individual chargers in a single package. Connect each set of 12V leads to each battery. Set #1 goes to the start battery. Set #2 goes to auxiliary #1 and set #3 goes to auxiliary #2. Each set of leads is isolated from the others so there is no problem charging batteries in a 24V configuration. That's what the charger is designed for.

 

[Boatin Bob]

Re: charging 3 way switch

I don't know for sure that the promatic 30-3 will do what Ferris wants but they do make a couple the protournament 150 and 300 that fit his needs to a T. One 12V engine battery & two 12V trolling motor batteries used in 12V, 24V or 36V configuration. These Chargers are designed for use in Heavy duty or professional applications. I would contact them directly and ask them...see this webpage Chargers

 

[Silvertip]

Re: charging 3 way switch

He doesn't need a switch at all. Here are the specs for the Promatic 30-3. <br /><br /> http://pmariner.com/productFeature.php?ProductNum=51233&page=2

 

[ferrism]

Re: charging 3 way switch

OK guys, thank you so far. When I hook up the neg and pos wire from the battery charger to the 1st aux battery in the 24 volt configuration to the battery charger, I'm OK to go. Then I hook another neg wire from the charger to the 2nd aux battery and it is OK, but when I hook up the pos wire from the charger to the pos post on the 2nd aux battery in the 24 volt configuration, I get an ark, which means to me that something ain't right down here in the Ozarks of Arkansas. Thanks, Ferris

 

[ferrism]

Re: charging 3 way switch

I'm not sure another battery charger is the answer, plus, I'm trying not to invest too much into this problem. Right now it takes me about two minutes to disconnect the battery and put the 3rd set of leads on to charge all three batteries. This I do about 4 times a week, so a switch would be nice. Thanks, Ferris

 

[Silvertip]

Re: charging 3 way switch

Are you sure your charger is functioning properly? With the charger unplugged, connect an ohm meter across each the positive and negative leads of each output and jot down the reading. Reverse the probes and measure each one again. The first set of readings should all be the same and the second set should all be the same, although they will be different than the first reading. If you find one set of outputs different than the others, that says there's a problem with the charger. You would need a rather hefty switch between the two batteries to isolate them for charging, but single pole battery switches are available and they aren't terribly expensive. Just do a search for "battery switch". You don't need anything elaborate.

 

[Silvertip]

Re: charging 3 way switch

I did a little more searching on this and it turns out the 30-3 does not have 24V capability. The 21-3 does. So -- back to the battery switch to isolate the two batteries, or continue to isolate them when charging.

 

[demsvmejm]

Re: charging 3 way switch

Try this to separate the trolling motor batteries. Open the circuit between them and then connect your charger.<br /><br /> Battery Disconnect Switch <br /><br />or this<br /> <br />Battery Diconnect Switch <br /><br />Just be aware of the amperage limits.

 

[ferrism]

Re: charging 3 way switch

You have found almost what I was looking for, and after much searching and posting for a three way switch, this is the way I'm going to go. The battery disconnect switches are two pole switches that will remove the juice from the battery. I'll then connect the postitive lead from the battery charger with a clip, charge it, disconnect the battery charger lead and throw the switch back to the on position. This will work, thank you, Mr. Moore. Ferris

 

[ferrism]

Re: charging 3 way switch

To Upinsmoke. No, I didn't check the battery charger, but it was working up to when I installed the new 24 volt trolling motor. Just to be sure, I will check it out. Thanks. Ferris