Why I couldn't get this to work. Charging the batteries in the camper with DCDC.

[@conellisgreatadventure8864]

Klarmann is an absolute legend. He’s the sort of bloke that’s happy to share is knowledge. I’ve got a Redarc manager 30 in my camper which has an inbuilt isolator. I’ve inherited spaghetti from previous owner and slowing upgrading wiring etc. good to see your issue sorted

[@Haveacrack76]

I looked at the manager 30 for ages for the camper. Im still on the fence about it. Thanks mate

[@conellisgreatadventure8864]

@@Haveacrack76 I’m on the fence if I should put one on my patrol when I re do the 12v system in a few months. Besides the price issue there a bloody good bit of kit. Set and forget 🙂

[@Tracey-eq8qj]

I had the same problem with my set up, I upgraded the wiring to 6 B&S and fitted a cheap voltage sensing relay in the trailer as mentioned in another comment. Works perfectly now.

[@Haveacrack76]

Cheers mate

[@ailo4x4]

Great timing! I'm doing the same thing RIGHT NOW. I just removed my aux battery in the the truck and disconnected it from the very same isolator. Then ran the Anderson plug cabling to the back of the the truck. I'll connect he DC-DC charger exactly as Heiner and you showed. What I still can't quite figure out is; "how do I ALSO have an AGM aux battery in the truck?" If you get an answer, I'd love to know. Cheers from over here!

[@Haveacrack76]

If it were me, I would put a charger for it. But there may be a cheaper way to do it.

[@SirLuisBarrera]

if you are having voltage drop at the charger input either your cable is too thin for the run or your connection have losses. take a multimeter and measure the voltage at each section and you will find the culprit. By doing a quick check you should be running b&S 3 for 5m run on a 40amp dcdc charger

[@Haveacrack76]

Thanks mate.

[@MrRobinski]

Yes, not as simple as it seems. You told me you used 8 awg wire not 6 awg. Will have to get my head around it when im back from my trip 😅

[@Haveacrack76]

Cheers mate. I have upgraded the wire in the vehicle to 6B&S.

[@greghunter4383]

Trailer back wiring looks a bit thin?

[@Haveacrack76]

In the battery box? Yes its something I need to fix.

[@xgouldiex]

You could of just used the voltage sensing relay/switch to turn on the ignition live on the b2b

[@Haveacrack76]

Cheers mate

[@bencole9936]

Cable from my vehicle to my caravan is 25mm2 If its smaller, your calcs are wrong

[@Haveacrack76]

Thanks mate

[@thelonewolf666]

youve made it over complicated, disable smart alternator first and the 4 gauge wire

[@Haveacrack76]

Possibly. I liked the idea he came up with and it works. Cheers mate

[@markeh1971]

Hi, love Smart Alternators, great for fuel saving on a test cycle! Not so good in real life. Focuses and Kuga’s have a fuse you can pull and disables the feature…….. Who would have thought of that I wonder. Take care M.