duel battery switch....

[Lukiebs]

Hi All.
Just seeing if you can change from one battery to the other or to both while engine is running?? I know you cant turn it to off position but just want to know for reference. Also if one is the crank and use the other for accessories can you crank off both batteries separately if needed. If that makes sence.

Thanks

 

[sasto]

Re: duel battery switch....

If your battery switch is ignition protected you are fine. I don't recommend you turning the battery switch to off. Yes you may start off either or both batteries.

 

[Silvertip]

Re: duel battery switch....

Ignition protection is just one feature. A more common term is that the switch must be "make-before-break" which merely means the switch makes the "new" connection before breaking the "existing" connection. Don't know of any current generation switches that are not made that way but then that doesn't mean they don't exist.

 

[seabob4]

Re: duel battery switch....

All modern switches are "make-before-break". But in the case of moving through the "OFF" position, the problem here is the alternator output has no where to go, so the diode on the alternator gets fried. If you have a switch (they all sell these) that has an "Alternator Field Disconnect" feature, your safe moving through the off position with the engine running...

 

[sasto]

Re: duel battery switch....

If I were to wire an Alt Disc. to a battery switch that has this feature, what circuit is used at the switch. Then I would assume the alt recieves it's voltage regardless if the batt. switch in the off position? Is there any reason to run a a boat with this type alt. with the batteries disconnected from circuit, except maybe in an emergency situation? Learning something new everyday.

 

[seabob4]

Re: duel battery switch....

Sasto,
You might find this interesting reading...
http://bluesea.com/viewresource/91

 

[sasto]

Re: duel battery switch....

Thanks seaBob, when it comes time for me to address this situation I will know what to expect. I can only assume if I don't have a "field" connection on alt then I would have an internal regulator? Is there a problem in running an engine without battery power on an internal regulator. Never have before, (on purpose) but curious.