Contactor, Switch, or Relay?

[Electron_Sam78]

Does anyone know of a device (contactor, relay, or switch) that can perform the required function as laid out in the drawing? It needs to be manual operation not coil operated.

I can do it with a 4-way switch but the only problem is that it connects the chargers in series when the circuit is not in charge mode. That could potentially be a problem.

 

[weressl]

Does anyone know of a device (contactor, relay, or switch) that can perform the required function as laid out in the drawing? It needs to be manual operation not coil operated.

I can do it with a 4-way switch but the only problem is that it connects the chargers in series when the circuit is not in charge mode. That could potentially be a problem.

http://www.krausnaimer.com/0/main.htm can build you any switch you can describe.:smile:

 

[KentAT]

http://www.krausnaimer.com/0/main.htm can build you any switch you can describe.:smile:

We also use some smaller krausnaimer switches.

Are you sure of your layout drawing?


As it is, the switch is placing your batteries in series, for 12V, and neither charger is in use.

Switching the switch connects each charger to a battery, and breaks the 12V series. Can't tell the whole story without each (+) and (-) terminal identified.

What exactly do you need to do?
Do you want to go from no charger in service to one in service, or from none to both in service?
Do you need "make before break" contacts?
What load rating do you need for the contacts?

kent

 

[Electron_Sam78]

...As it is, the switch is placing your batteries in series, for 12V, and neither charger is in use.

Switching the switch connects each charger to a battery, and breaks the 12V series.

...from no charger in service ... to both in service...

Yes, yes, and yes.

...Do you need "make before break" contacts?

Not sure. I need it to be either charging (the batteries separated) or in use (the batteries in series for 12 volt load)

...What load rating do you need for the contacts?

6 amps at 12 VDC

This is in reference to my earlier post: http://forums.mikeholt.com/showthread.php?t=113662

 

[Brian Oshman]

You don't need any switches. Just connect each charger to each battery. It really is as simple as that. They will both operate separately. Since you are placing the pos from one and the neg from the other in the middle it is just like a center tap. It will just charge them separately and there is no need to disconnect any of the circuit. You could put both chargers in series and not connect to the common point in the middle of the two battreries and that would work too but it would charge faster if you connect the common in the middle.

 

[LarryFine]

You could put both chargers in series and not connect to the common point in the middle of the two battreries and that would work too but it would charge faster if you connect the common in the middle.

In theory, it shouldn't make a difference, but battery variations would make the common connection a good idea.

For that matter, only three contacts are necessary for the disconnecting plug and socket, not four.

 

[Brian Oshman]

^^^^^I agree, only three connections from the charger are needed. It was just for the purpose of the drawing. You could use a trailer plug for the connector.

 

[Electron_Sam78]

So you guys are saying I could do this and it would be the easiest method and still be as effective/safe as disconnecting the series bridge and charging separately?:

 

[LarryFine]

So you guys are saying I could do this and it would be the easiest method and still be as effective/safe as disconnecting the series bridge and charging separately?:

That's what we're saying.



It may be incorrect, but it's what we're saying.



Added: To be sure, plug in the two chargers with the outputs isolated and see if you get any voltage between either wire from one and either wire of the other.

 

[Brian Oshman]

Here is an even better way to do it. Just put your single pole load switch in between the batteries. Use a 4 pin trailer plug for the charger connection and they will be isolated.

Very simple.

 

[K8MHZ]

Why not just use a single 12 volt charger to charge the two 6V batteries in series?

That's how every residential type UPS I have ever seen works.

All a 12V battery is is two 6V batteries in series, anyway. Why the need for two chargers?

 

[Electron_Sam78]

Why not just use a single 12 volt charger to charge the two 6V batteries in series?

That's how every residential type UPS I have ever seen works.

All a 12V battery is is two 6V batteries in series, anyway. Why the need for two chargers?

because I'd have to buy a 12V charger. I already have two 6V chargers! Freebie! Also I've heard the argument that batteries, even with the same ratings discharge at slightly different rates and therefore one can be overcharged while one is still charging decreasing the life of the battery that is overcharged

 

[Electron_Sam78]

Here is an even better way to do it. Just put your single pole load switch in between the batteries. Use a 4 pin trailer plug for the charger connection and they will be isolated.

Very simple.

Wow, that's a great idea! I love different perspectives. This site is awesome!