parts needed for two battery set up for 470

[fmalott]

I did the alternator conversion already. right now i have a 74 amp alt. i want to convert to a two battery system, i want one battery to run every thing like normal but i want the other to run the radio and bilige pump i know i have to wire the radio and bilige pump to run off one battery only, but my question is how many amps should the alternator pushed out and what do i have to do to have the alternator charge two battries is there anything special i got to do other than join the two positive terminals and join the two negative terminals

 

[stonyloam]

Re: parts needed for two battery set up for 470

You need a marine battery isolator like this: http://bluewatermarinesvc.com/html/bat_isolator.html That should do what you need. Add a battery switch to connect the two batteries together should the need arise. The 70 amp alternator should do the job. You might also want to add a 2 bank battery maintainer/charger to keep your batteries fully charged all year (including during winter storage).

 

[Silvertip]

Re: parts needed for two battery set up for 470

One more misinterpretation of how a dual battery switch should be used. You wire everything on the boat except an automatic bilge pump to the COM terminal on the switch. Scan this forum as there at least three recent posts on how to do this properly. You use the switch to determine which battery will power things, which battery gets charged, and which battery will start the engine. Doing it your way limits the functionality and versatility of having the switch in the first place.

 

[fmalott]

Re: parts needed for two battery set up for 470

the more i looked into it the more i understand on what you guys are saying i get it thanks

 

[thumpar]

Re: parts needed for two battery set up for 470

I went with a battery isolator and no switch. The first battery if for vitals like start, trim and bilge. The other is for radio, fish finder, lights and other none vital stuff.