What you should know when ordering from us online (click here)

Battery Isolators & External Rectifiers

The POWERLINE Battery Isolators are one of the finest on the market. They allow each battery bank to charge according to its own needs and have the capability to handle the total amp rating at either battery bank. 

Example: Let us take a simple designed Battery Isolator and compare it with a POWERLINE Battery Isolator. Both are rated at 150 amps, and both have 1 alternator and 2 battery posts. The simple designed Isolator can handle 150 amps coming in from the alternator post but CANNOT handle the full current (150 amps) coming out of a single battery post on the battery Isolator. This is because they do not have enough diodes and/or heat sink area to handle the full current and will burn out that side of the battery isolator. The way they get the amp rating is by adding up the sum of what each battery post can handle; 75 amps maximum thru either side.

On the other hand, the POWERLINE Battery Isolator has more than enough diodes and heat sink area to allow the full current of 150 amps to flow through either of the battery posts. Meaning with our 150 amp Battery Isolator you could potentially have the full 150 amps flowing through either side and not do any damage to the isolator. Example, the B2 battery cable has a bad terminal and has burnt off at the battery, leaving no power being fed through the B2 output post of the isolator. The B1 output post of our isolator will now be able to have the full 150 amps from the alternator going to it and not be destroyed from the extra current that can now flow through it. (Our 150 amp isolator has 3 70-amp diodes in parallel on each battery post, giving you the capability to handle a total of 210 amps Cold on either battery post!)

This example may not always happen but its certainly possible, especially if your not properly maintaining your charging system. We take these type of possibilities into consideration when designing our products. This allows you to still operate and get to your destination, even with blown diodes on one side. 

The amperage printed on our battery isolators label is the amount of power you can run through each battery post without having to worry about burning up your battery isolator.

These are TRUE Heavy Duty Battery Isolators



  • Powder-coated heat sink for long-lasting, corrosion-resistant finish (Silver finish is our standard) 
  • All internal components epoxy-potted for extreme durability (Fully Solid, no moving parts)
  • Heavy-duty 2" wide diffuser bar
  • Thermal heat transfer tape for cooler operation
  • More cooling fins then most products in the market
  • Underrated power-handling ability (Ex. Our 150-Amp Isolator can handle 210-Amps Cold)
  • Standard negative ground (positive ground available upon request)
  • Models available for Delco CS Alternator compatibility 
  • 70-400 Amp rated models available
  • Capable to work with 12 Volt, 24 Volt and even 48 Volt applications
  • 2 year warranty

33HD Battery Isolators

See all models


View 33-53

Do you have an older POWERLINE Battery Isolator model? Does the Model # start with "22" or "PLI"?

If you do, CLICK HERE to find out which 33 series model replaces your older PLI Series or 22 Series model.


External Rectifiers

View External Rectifiers