Add-A-Battery Kit, Marine Battery Switch and Charging Relay, Ignition Protected, Up to 120 amp


Add-A-Battery Kit, Battery Bank Management Set, 120A
SKU: 167731
Mfg# 7650
LFS# BSS7650
UNIT: Each
Out of stock - Typically Available in 3 - 6 Weeks


Add-A-Battery 120amp Kit includes an ignition protected dual circuit Blue Seas e-Series battery switch and a 12/24v Automatic Charging Relay (ACR) rated for use with alternators up to 120 amperes. These components simplify switching and automate charging, so that all you have to do is turn the battery switch ON when you arrive and OFF when you leave.

Read our article on step-by-step instructions on how to use the Add-a-Battery

Dual Circuit Plus Battery Switch simplifies switching

  • Isolates engine and house circuits
  • Combines batteries for emergency starting
  • Make-before-break contact design allows switching without power interruption
  • Ignition protected „ safe for installation aboard gasoline powered boats
  • Case design allows surface or rear panel mounting
  • Tin-plated copper studs for maximum conductivity and corrosion resistance

ACR Automatic Charging Relay

  • Automatically combines batteries during charging
  • Isolates batteries during engine cranking and when not charging
  • Shares the charge between two batteries more efficiently than a battery isolator
  • Allows efficient dual battery charging without needing regulator adjustment or rewiring

With the Add-A-Battery Kit boaters can increase their boat's safety by setting up a dual battery system that is easy to(more...)

WARNING: This product can expose you to chemicals including arsenic, which is known to the State of California to cause cancer, birth defects, or other reproductive harm. Do not use in connection with drinking water. Wash hands after handling. For more information, go to



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Blue Sea Systems stands behind its products for as long as you own them. Blue Sea Systems will replace or issue a credit for any of its products found to be defective in materials or manufacture. P12 Battery Chargers and P12 Remote Displays are warranted for a period of five years from the date of first purchase. Digital Meters and Vessel System Monitors are warranted for a period of three years from the date of first purchase. No compensation will be allowed for products not returned to Blue Sea Systems for analysis, nor will compensation be made for labor required to replace any defective product


  • All returns must be received within 30 days of receipt of the order.
  • Manufacturer defects reported within 30 days of receipt will be supplied a pre-paid label for return shipping upon approval.
  • Please contact Go2marine LFS Marine and Outdoor for Manufacture Defects, Returns and help with Warranties.