yet another dual battery setup, smart or no?

[ZRotheohv]

I have a dual battery plan that'll run an aux battery at all times unless either starting or running (alternator good signal, start signal, or manual switch parallels the batteries) and I just wanted to know if it would be a good idea. I'd use a starting battery for starting (obviously) and it would only be in the circuit during starting and running, while the aux battery would be a deep cycle and would be in the circuit at all times (for running things with the engine off). I plan on using a Bluesea solenoid to parallel the batteries. My question is if it would be okay to parallel the batteries when starting if the aux deep cycle battery was dead. I was also thinking about putting a manual switch in there to turn off the aux battery if it would sap too much from the starting battery if it was completely dead. Does this seem like a good system or am I just stupid and going to start a huge fire? Thanks!

Zachary Rothe

 

[soggy60]

Sounds like you'd only have the starting battery 'o9n line' when starting & running.

If 'aux' bat is dead and you try to start, binging the start battery on-line, the dead aux bat will bring down the start battery. If the aux bat died because of internal short, this could bring down the start battery quickly....

 

[beaufort-fj60]

 

[srplus]

sounds like the long way around the block

why not just install a battery switch... that way you can run or charge either or all batteries depending upon needs. like they use in boats. a url for this is:
http://www.westmarine.com/webapp/wc...&N=0&storeId=10001&Ntk=All_2&ddkey=SiteSearch


and there is even one that they call 'cruiser and universal'. these are available all over the place cheap! some even give you the ability to shut off all battery use by removing the key. that would keep your cruiser from being stolen and in that vein (stolen from another post on this site) you could install this:

http://www.break.com/index/trunkmonkey.html

which sometimes works and sometimes does not.