matson MA98411, Manual

COMMON APPLICATIONS

Dual Battery Charging

One of the major uses of the MPVSR is in dual battery charging 

applications. The MPVSR is used to put the two batteries or banks of 

batteries into parallel once the primary battery or bank reaches a certain 

voltage. In a 4x4 application, where a secondary battery is used for 

accessories such as lights, fridges or winches, it is important to protect the 

vehicles starting battery from being flattened by the accessories, making 

sure you can always start the vehicle and drive away. The MPVSR, 

installed between the starting battery and the secondary battery, can put 

the batteries in parallel once the starting battery is charged, or reaches 

a user defined voltage, allowing charging of both batteries to occur while 

the vehicle is driving. If a load is placed on the batteries whilst in parallel, 

and the starting battery drops to a pre-determined voltage, the MPVSR will 

disconnect the two batteries, allowing the secondary battery to power the 

accessories and protecting the starting battery.
The ability to determine the cut-in and cut-out voltages of the 

MPVSR, specific to the vehicle, makes this product perfect for 

modern vehicles with VARIABLE VOLTAGE OUTPUT ALTERNATORS.
Setting Guide: (note, this setup requires the MPVSR bet programmed 

‘normally open’)
UPPER LIMIT IN VOLTS: This is the voltage that, when reached by 

the starting/primary battery, the MPVSR will put the batteries in parallel 

and charge both batteries. For vehicles with a VARIABLE VOLTAGE 

ALTERNATOR, this will need to be set relatively low, at a point just below 

the higher voltage output of the alternator. You will need to contact the 

manufacturer or dealership to find this information.
LOWER LIMIT IN VOLTS: This is the voltage level that, when reached by 

the starting/primary battery, the MPVSR will disconnect the batteries from 

the parallel circuit and isolate the starting/primary battery. This needs to be 

set at a voltage level greater than the minimum voltage level required to 

start the vehicle
UPPER DELAY IN SECS: This setting, in seconds, is the amount of delay 

the MPVSR will wait to put the batteries in parallel, after the primary/

starting battery reaches the UPPER LIMIT IN VOLTS. This delay stops 

VSR ‘chatter’, caused by the primary battery voltage dropping when the 

batteries are put in parallel and the VSR continuously connecting and