Would this switch work to hook 2 batteries together?

[Winkfish]

Maine Sail, I had asked about connecting two dual purpose batteries on my fishing boat. One battery does the starting. The other runs electronics, like the vhf, gps. I asked because I wanted to charge both batteries with the motor while running. Your answer was great. Thanks.

Life being what it is, I had not done it yet. Since then, I saw this switch at West Marine

http://www.westmarine.com/webapp/wc...toreNum=50523&subdeptNum=50543&classNum=50547

Specifically the middle one (#6006). I'm thinking that if I use this switch to connect the two batteries, I can turn it on while running to charge both batteries, then off while anchored so as not to run down the starting battery. The switch would only be connecting/isolating the batteries. No loads would come from the switch.

Would this work? Any downsides? Thanks!!!

 

[seadaddler]

Yes

Yes I use a switch just like it,my house bank has 4 -6volt Trojans and a start battery just for start motor and Gen and use a switch just like you show to connect both just incase my start battery go dead and it charges also.
Nick

 

[Dantodd]

The reason such switches are usually counseled against is not due to switch failures. What usually happens is, one day we all forget to turn the switch off at the right time and end up killing both batteries while on the hook.

A voltage sensing relay or DC to DC charger is much more reliable and is under $150. I think I paid $120 for the Xantrex echo charger I use to charge my starter off the house bank. The AC charger and alternator both feed the house bank and the echo charger automatically maintains the starter battery. I have an emergency interconnect if I ever need to use the house bank to start or vice versa.

For your application I suspect the voltage sensing relay might be a better solution and the Blue Seas ACR runs about $80. It is specifically designed to isolate the banks during discharge, preventing electronics drop out during starting or running both banks down on the hook as well as combining both banks while charging.

 

[Maine Sail]

The reason such switches are usually counseled against is not due to switch failures. What usually happens is, one day we all forget to turn the switch off at the right time and end up killing both batteries while on the hook.

A voltage sensing relay or DC to DC charger is much more reliable and is under $150. I think I paid $120 for the Xantrex echo charger I use to charge my starter off the house bank. The AC charger and alternator both feed the house bank and the echo charger automatically maintains the starter battery. I have an emergency interconnect if I ever need to use the house bank to start or vice versa.

For your application I suspect the voltage sensing relay might be a better solution and the Blue Seas ACR runs about $80. It is specifically designed to isolate the banks during discharge, preventing electronics drop out during starting or running both banks down on the hook as well as combining both banks while charging.

Ditto, let the charging happen automatically...

 

[Winkfish]

Thank you all for your replies!!