Which Size Fuses Are Needed To Install Redarc BCDC Battery Charger 331-BCDC1225D?
Question:
So on my install of bcdc1225D it calls for 40 amp fuses between start battery and the charger and another 40 amp between charger aux battery. Installing a 331-sb112-LLD isolator for my lithium aux battery shows it installed after lithium battery towards load and it calls for a inline fuse after the lithium battery and it’s a 60 amp fuse. Is this correct?
asked by: Mike
Expert Reply:
The Redarc In-Vehicle BCDC Charger # 331-BCDC1225D you were looking at requires a 40 amp fuse between the charger and the start battery, a 40 amp fuse between the auxiliary battery and the charger, and another 40 amp fuse between the auxiliary battery and the load. This is shown in the included diagram for Lithium batteries.
The isolator # 331-SBI12-LLD you are using does not count as a fuse.
Redarc recommends using their 40-Amp MIDI Fuse Kit # 331-FK40, and since two fuse holders are included with the kit but you need to add three fuses you will need to order two of these kits.
I included videos of the products mentioned for you to take a look at.

Products Referenced in This Question
40-Amp MIDI Fuse Kit for Redarc In-Vehicle 25-Amp BCDC Battery Charger
- Accessories and Parts
- Battery Charger
- Fuse Kit
- Redarc
more information >
Redarc Smart Start Load Disconnect for Manager30 or BCDC with Lithium Battery - 12 Volt - 100 Amp
- Battery Charger
- Battery Isolators
- 12V
- Vehicle Battery to Auxiliary Battery
- Redarc
more information >
Product Page this Question was Asked From
Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 25 Amp
- Battery Charger
- Battery Charger
- RV/Camper
- Trailer
- 75 Ah
- 200 Ah
- Charges/Maintains
- DC to DC
- 12V
- Solar Panels to Auxiliary Battery
- Vehicle Battery to Auxiliary Battery
- Redarc
more information >
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