Why is Relay Kit for Redarc In-Vehicle BCDC Battery Charger Needed for Smart Alternator

Updated 12/19/2018 | Published 12/18/2018

Products Featured in This Question

60-Amp Relay Kit for Redarc In-Vehicle BCDC Battery Charger

(5)

$125.00

Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 25 Amp

(87)

$535.00

Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp

(87)

$620.00

Question:

I just read where a tech on this site said this relay is REQUIRED with the variable alternator? Why would you need this when it can just be connected to the ignition like the manual states, that is unless maybe a long run to a trailer? I use this on a 2015 F250 with a 2nd battery for my winch and inverter with the blue wire on my ignition. Volt meters show seperate charging of each batt...

asked by: Steve

Helpful Expert Reply:

The 60-Amp Relay Kit for Redarc In-Vehicle BCDC Battery Charger # 331-RK1260 is needed - but not necessarily required - for use with the Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1225D (25 amp) or # 331-BCDC1240D (40 amp) with a smart alternator because those chargers require starter battery voltage and running an ignition feed to the charger can be difficult. Your example of a long run to a trailer is on the money and exactly what it would be needed for.

I have added a cut out of the manual of the relay kit which details this.

expert reply by: Kyle S