Battery Box Controller
The next step in my auxiliary battery box solution is a DCDC charger controller box.
I’m a fan of the quality brands, Victron and Redarc and have had a good experiences with both including the Redarc RedVision vehicle management system fitted to my camper trailer. For my use case and to keep things compact I wanted a combined DCDC/solar charger which ruled out Victron. Looking at the Redarc options I rather liked their recently released BCDC Alpha which comes in 25 and 50 amp capacities. Compared to their other DCDC chargers it had some nice features including:
- Bluetooth configuration and monitoring.
- Reverse charging ability. You charge a flat starter battery from the auxiliary and charge the starter from a solar panel once the aux battery is fully charged
Like all Redarc gear they’re not cheap, but the Christmas sales came to the rescue again and I found one at a good price online. Though I didn’t need the extra capacity I went for the 50 amp model as there wasn’t a lot of difference in price and it will give me a bit of future proofing and growth potential if needed.
Ultimately, I decided to make a separate controller box rather than mounting it to the vehicle or the battery box I bought (more to come on this). Taking inspiration from @DennisM’s box (
https://www.theineosforum.com/threads/adding-a-third-battery.12417621/post-1333318547) I made a simpler/smaller one as pictured below.
Rather putting fuses on/in the box I kept things simple and followed Redarc’s recommendation placing the input fuse close to the start battery on the Anderson pigtail I previously installed. On the other side the Auxiliary battery box already has a fuse. One small downside of the Redarc alpha is that they don’t fit a protective cover over the terminals. I used a small strip of scrap neoprene rubber held down with a few dabs of contact cement, which hopefully will stop any accidental short circuits.
Moving on to the ignition sensor wire, I used a mini fuse piggyback tap with a 3amp fuse. The tap had square ended fuse blades so I had to gently file them back to a taper so it could be easily inserted the fuse box.
The next small challenge was finding a fuse in the interior electrical centre that was ignition switched. Ultimately, I tapped into the Power Mirror 5 amp fuse (FI38) position as it is not a critical circuit, only live when the engine was running and critically had enough clearance around it to allow the tap to seat properly.
First test using my 20year old battery box and AGM battery I had given my son worked all to plan. Once I get my lithium battery (its still on back order!) I'll update this thread with the new battery box and my impressions.
Cheers
Steve
