User Manual
Specifications
Part number SBI12
SBI12D
SBI24
SBI24D
SBI212
SBI212D
SBI224
SBI224D
Turn-on voltage 13.2V 26.4V 13.2V 26.4V
Turn-off voltage 12.7V 25.4V 12.7V 25.4V
Continuous load rating 100A 100A 200A 200A
Inrush load rating 400A 400A 600A 600A
Standby current <4mA <4mA <4mA <4mA
Dimensions 75 x 70 x 80mm 75 x 70 x 80mm 90 x 95 x 100mm 90 x 95 x 100mm
Weight 300g 300g 800g 800g
Smart Start
®
 SBI Battery Isolators
Designed primarily for use in 4WD and commercial 
vehicles with a dual battery setup, the Smart Start
®
SBI ensures that a low charge in the secondary 
battery won’t drain the primary battery.
It is available in four models; 12 or 24 volt DC 
incorporating 100 or 200 amp continuous ratings. 
The 200 amp models are designed for extremely 
heavy-duty operations, as found in industrial and 
mining situations
The Smart Start
®
 SBI monitors the start battery 
and the charging system. When the start battery 
reaches 13.2 volts on a 12 volt system (26.4 volts 
on a 24 volt system) the solenoid will connect the 
auxiliary battery to the charging system. Once 
the engine has been turned off the Smart Start
®
SBI monitors the start battery voltage and, when 
this drops below 12.7volts on a 12 volt system 
(25.4volts on a 24volt system), the solenoid 
will turn off, isolating the start battery from the 
auxiliarybattery.
The Smart Start
®
 SBI features sophisticated fault 
detection and LED indication of operation to warn 
the user of faults that include over-voltage, voltage 
drop and excessive current draw conditions. It also 
features power saving technology. This means the 
unit will only draw approximately 120 milliamps 
when on and generate less heat allowing it to 
operate at a much cooler temperature. 
The Smart Start
®
 SBI is better than a diode battery 
isolator due to the voltage drop associated with 
diode type isolation. 
The solenoid features silver contacts for longer life 
and is suitable for marine applications. 
The Smart Start
®
 SBI incorporates electronic 
components that will prevent the solenoid from 
generating high voltage transients making it ideal 
for use on modern vehicles fitted with computer 
control systems. 
Fuse size recommendations
Fuse recommended for pushbutton override Fuse recommended for no override
SBI12/SBI24 100 amps 60 amps
SBI212/SBI224 200 amps 120 amps
Dual sensing Smart Start
®
 models
SBIXXD models isolate the start and auxiliary 
batteries when the auxiliary battery may also 
becharged by an external source, like solar. 
They allow the start battery to be charged by the 
external source once the auxiliary battery reaches 
13.2 volts - useful to top up the start battery from 
a solar charge source or an external AC battery 
charger connected to the house or auxiliary 
battery. They operate as standard SBIs 
when the start battery terminal of the 
SBI receives more than 13.2volts (12V 
system) or 26.4 volts (24V system).
Smart Start
®
 dual battery isolator 
and wiring kit
The Smart Start
®
 Dual Battery Isolator 
and Wiring Kit (part number SBI12KIT) 
has everything needed to install a Smart 
Start
®
 Dual Battery Isolator including 
the Smart Start
®
 itself. It requires no 
crimping or soldering, it’s just plug and 
play. The SBI12KIT features high 
quality MIDI 60 amp fuses 
and MTA fuse holders with 
the corresponding ring 
terminals already attached 
to the wires.
Want to know more?
Scan this QR code with  
your smartphone to go to  
the Redarc website
Gauge value packs
For monitoring a 
dual battery setup
SBI12-GK
Smart Start Battery 
Isolator with dual 
voltagegauge
SBI12KIT-GK
Smart Start dual 
battery isolator and 
wiring kit with dual 
voltage gauge
VALUE PACK
A B
Loads*Load
circuit breaker
* Circuit breaker and fuses not supplied
Auxiliary
battery
Start
battery
Start
battery
Override
wire
Fuse*
Fuse*
Auxiliary
battery
Winch
Fuse Fuse
Winch
switch
SBI with push button for start assist
Override
wire
5A
fuse
Momentary
pushbutton
Winch from both batteries
Standard SBI installation
Winch
solenoid
Australia
Phone   (08) 8322 4848
Fax   (08) 8387 2889
International
Phone   +61 8 8322 4848
Fax   +61 8 8387 2889
REDARC Electronics
ABN 77 136 785 092
23 Brodie Road (North)
Lonsdale, South Australia
Australia 5160
power@redarc.com.au
Details and specifications are subject to change without notice.  5618-180426
Copyright © 2018 REDARC Electronics Pty Ltd. All rights reserved.
Visit redarc.com.au for more information. 
SBI Smart Battery Isolators are available 
at your nearest auto electrician or 4WD 
specialty store.
®
SOLAR
READY


