Electronic Grounding

[jslipher]

I just installed a 2nd battery. I decided to run the power from all of my stereo and house electronics to the new 2nd battery. I grounded the stereo to the new 2nd battery, BUT I forgot to change the ground of the house electronics. The house electronics are being grounded to the original 1st battery (now starter battery). Will this cause any issues? Do I need to ground all of my non-starter electronics to the 2nd battery or will it be fine to be left as-is? Thanks for the help!

[MLA]

Need to clarify your setup. Did you install 2nd battery in parallel to the original battery i.e making one large battery. Or, did you install a 2nd "bank" with some sort of dual bank battery switch?

If the later, then we need to know what switch type you have. If the first, then it doesnt mater as the grounds are all common anyway. 

[Slurpee]

Well your house electronics will only work at all if there is some connection somewhere in your boat that ties the negative terminals of the 1st and 2nd battery together.  Otherwise your house electronics if they're trying to work are going to be trying to find a ground path back to the new battery through any path available.  Like interconnects and such.  That's not good.  

But if you have a heavy gauge connection for GND back to a bus for both batteries for a charger or something then you don't have any worries on unwanted GND currents.

Honestly running everything off the starter battery but your audio is probably the most common hookup.  Depending on what you've got for "house electronics" they can introduce noise into the power for the audio and potentially create something you can hear you don't like.  Hums, pops, less quality signal, etc.  Mostly nuisance stuff.  That's all "could" mind you.  Not "will".  Too many other things contribute to that scenario.  

 

[jslipher]

Thanks for the responses. It sounds like I should probably run the house grounds (bus bars) specifically to the 2nd battery to be safe. The reason I'm running all house electronics to the 2nd battery is because of the music control through the driver's helm screen rather than the separate head unit. I guess I could try and run the headunit power to the 2nd battery and ignore the fact that the driver screen is going to a different battery. That way stereo only would be to the second battery. Downside to that is the driver screen and other electronics could cause the starter battery to go dead if I'm floating playing music for an extended period.

My current as-is setup:

• Main starter battery
  • Positive feed goes from starter to Blue Seas red switch (https://www.bluesea.com/products/6011/m-Series_Mini_Dual_Circuit_Plus_Battery_Switch_-_Red)
  • Positive feed comes from red switch to the starter battery
  • Positive goes to ACR Relay (https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A)
  • Positive comes from ProMariner dual bank charger
  • Ground comes from House electronics
  • Ground comes from starter
  • Ground comes from ProMariner dual bank charger
• 2nd battery
  • Positive feed goes from stereo amp board and House electronics to Blue Seas red switch (https://www.bluesea.com/products/6011/m-Series_Mini_Dual_Circuit_Plus_Battery_Switch_-_Red)
  • Positive feed comes from red switch to the 2nd battery
  • Positive goes to ACR Relay (https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A)
  • Positive comes from ProMariner dual bank charger
  • Ground comes from stereo amp board only
  • Ground comes from ProMariner dual bank charger

[MLA]

That answers the question of what setup you have. So going out on a limb, id say your two batteries are in the port locker area and real close to each other. In reality, it really does not matter which battery what components ground to as there should be an ample size cable between the banks. This makes all ground common to the main ground cable going to the block. The switch isolates the banks' B+'s, so the grounds wont make one load draw off the other bank. 

Now, it mike look different on paper from how it reads, but read a couple things that perk my ears up so to speak, in you previous post. Separate head unit from screen? Helm screen on #2, head unit on #1? ACR to batteries?