Cranking Power

The BIC-95150B can handle up to 150 amps for a significant power boost  when a main battery will almost crank (clicking solenoid) or cranks slowly. But, in a typical installation, we aim to limit the peak demand, to the Auxiliary battery side during charging, to about 60 to 80A by using 8 AWG wire and a minimum length of 20 feet along with 50A or 60A continuous rated circuit protection. So, this wire size and length will also limit the cranking voltage/current delivered to a starter. This is one reason it is insufficient for the full cranking load. But, as stated above, it can assist (provide a boost) with a weak main battery.

The BIC-95300B can handle up to 300 amps to fully crank your typical gasoline engine even with a completely discharged main battery.  To properly acheive this capability, you must use properly sized wiring and a properly rated (in terms of CCA) backup battery.   The backup battery should be (CCA) rated at least as high as the original vehicle manufacturer's main battery.  For this application, a higher CCA rating is better. 

If you have an unusual application that requires even higher currents (such as a full size Diesel Engine), then you can parallel the units as needed.  A typical automotive Diesel Engine will require 2 ea BIC-95300B units for backup cranking as well as two Backup batteries, if the engine requires two main batteries.  Large Diesel Engines may require more. We don't recommend attempting to use multiple BIC-95150B units for a full size Diesel Engine Backup start application because you would need 4 of them to do so. More typically, a pickup truck with a Diesel engine would more likely use one BIC-95150B for an Auxiliary battery setup such as for a slide-in camper application.