If you’ve ever had your RV’s house battery run down your starting battery you know you need an RV battery isolator.  An RV battery isolator separates the two batteries preventing the weak one from draining charge from the strong one while charging both batteries simultaneously from a single battery charger without having to connect the batteries together.

RV Battery Isolator: Keyline Chargers ISO-PRO140 Dual Battery Isolator Intro ViewIt’s common for RVers to replace setups where their auxiliary or house battery is connected to the chassis or vehicle starting battery for charging.  That’s because the existing setup may allow the auxiliary battery to drain the starting battery during storage periods leaving them with a dead starting battery.


Interested in learning about other battery solutions?  Be sure to see our other articles about some of the best!


If you connect an RV battery isolator to your circuit, you won’t have to worry about your starting battery going dead and leaving you stranded.  With the battery isolator between the two batteries, they remain disconnected unless the alternator or other charging source is supplying a charging voltage to the vehicle’s battery and then the isolator directs full charging to the house battery to charge it as needed.




It’s not all milk and honey with some battery isolators.  Diode battery isolators are available for RV use, but in most cases, they experience a voltage drop across the diode which limits the charging that can occur.  Diode isolators are also solid state devices and can be susceptible to voltage spikes and other power problems.


We searched RV forums, manufacturer sites, consumer sites, social media, customer review sites, and retail sites to find the most popular and highly rated RV battery isolator


Take a look at our choice and see if this dual battery isolator is the best battery isolator for your needs!


KeyLine Chargers Iso-Pro140 140 Amp Dual Battery Isolator Kit

KeyLine ChargersRV Battery Isolator: Keyline Chargers ISO-PRO140 Dual Battery Isolator Main View delivers some of the best smart battery chargers, maintainers, isolators, and accessories in the RV industry that meet the needs of the rugged, adventure, off-road, travel lifestyle.  Their KeyLine Chargers Iso-Pro140 140 Amp Dual Battery Isolator Kit is a reliable choice to prevent battery drain and always have a charged primary starting battery.  It functions as if you have two separate power sources for each battery while only having a single alternator or other charging sources.  It features Zero Voltage Drop, a compact size, easy installation, IP65-rated weather and strong vibration protection, and hyper-efficient programming that ensures your electrical system will function properly and your batteries will be properly charged.  This smart battery isolator will work perfectly in all your dual-battery vehicles, so you don’t get caught with a dead starting battery.



RV Battery Isolator: Features

  • 140-Amp, fully automatic, dual battery isolator kit
  • Zero voltage drop means the automatic battery isolator won’t rob power from your batteries or electrical systems
  • The Voltage Sensitive Relay (VSR) cuts in at 13.3-volts and cuts out at 12.8-volts to ensure your primary battery is always charged and is specially designed for RVs, ATVs, UTVs, boats, campers, 5th wheels, off-road vehicles, and more
  • Compact and lightweight it’s easy to mount just about anywhere you need it
  • Included mounting plate/template, simple power wire in/power wire out design, necessary hardware, and mounting instructions make installation a breeze
  • Durable construction and IP65 weather and strong vibration protection make this unit suitable for all off-road use in dusty, wet, extreme, and weather-exposed applications
  • Hyper-efficient programming ensures your electrical system will work without issues and your batteries will charge properly
  • Comes with 100% of the necessary hardware and mounting instructions
  • Dimensions are 2.6L x 2.6W x 2D inches
  • 1-Year warranty, no-questions-asked 100% customer satisfaction guarantee, and 30-day money back guarantee





Included Accessories

  • 1 – 20-foot red battery cable
  • 1 – 2-foot black ground battery cable
  • 2 – Positive brass marine-type battery terminals
  • 1 – Negative brass marine-type battery terminal
  • 1 – RV Battery Isolator: Keyline Chargers ISO-PRO140 Dual Battery Isolator Kit ViewSet of tinned copper lugs, heat shrink, and cable ties


Customer Reviews

See KeyLine Chargers Iso-Pro140 140 Amp Dual Battery Isolator Kit Customer Reviews >>>



  • No voltage loss
  • Easy to install
  • Compact size is easy to place
  • Outstanding performance



  • Included wiring is short and not high-quality
  • No visible indication that it is working










RV Battery Isolator




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Don’t get stranded when you’re starting battery goes dead by leeching from your house battery.  We sincerely hope that this article has provided you with valuable information that helps you choose the best RV battery isolator for your needs!