What is a Battery Split Charge Relay?

Thursday, 14 November 2013  |  AdrianR

Durite split charge relays  The battery split charge relay supplied at Arc-Components.com is a high load intelligent voltage sensitive relay unit, fitted between batteries for an efficient way of charging a secondary battery whilst not affecting the charge performance of the primary start battery. Designed for effective management of batteries and popular with the mobile home and marine communities, where start battery charging takes priority, once the charge level is UP on the start battery via alternator supply the unit switches over to charge the leisure battery.


Technical information regarding Arc Components Ltd split charge relays: Part No. 0-727-33 Voltage sensitive relay, 12 volt 140 amp with red LED indicator. Allows the split charging of a second battery, without discharging the primary/start battery, the relay makes at 13.3 volts and breaks at 12.8 volt.

A 5 second delay operates when the voltage falls below the cut-out voltage to prevent nuisance cut-out due to high intermittent loads on the battery. the unit is supplied with self-tapping screws and ring crimp terminal for ground lead.

Fitted between start and auxilary battery positives


The terminals (not supplied) for post connection have to be for M6 studs (example: 16mm2 cable requires 16-6 terminals) and the cable requires being of a large enough cross section for the alternator (charging source) maximum output. Cable entry is facilitated by cutting suitably sized holes in the side(s) of the relay, there are thinned out sections in the casing to make it easier.





Best application: common to mobile homes, water-craft and work vans, connected between the main start battery positive and the leisure battery positive.

A 24V version of this unit is available, part number 0-727-83.

view the products:

0-727-33 12V split charge relay

0-727-83 24V split charge relay

This blog post was created: 14th November 2013 and closed for comment 25th July 2015.

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