DC to DC Battery Charger (Newer Auto Stop Trucks)

[CharlieCali]

Hey everyone!

Planning out the battery system for my FWC Hawk.

I don't think I'll spend more than two nights in one spot ever because of my work schedule. So i'm leaning towards the Renogy DC to DC Battery Charger over Solar.

Anyone installed one of those on an Auto Stop Start Truck. I have a 2020 Silverado and am wondering if the auto stop function of the battery could cause issues with the controller.

Thanks!

Charlie

 

[kmcintyre]

Good question. Depending on your power needs, 2 days should be do-able with a house battery unless you are running the refrigerator, furnace, etc. a lot.

I don't know what the start/stop feature will do w/ the DC controller but I have the Victron DC-DC controller. I think there's a delay on when it'll start charging (acts as an isolator). I would expect that you could set it up for a longer period so when you in city driving, it stays off. I suspect you have a smart alternator too and not sure what settings there are for that but I remember reading something about them. If you do have a smart alt (or even if you don't) a DCDC charger is pretty critical for not damaging your alternator esp. if you have LifePO4 batteries. If you can afford the extra $70 (or more depending on the output) I'd get a Victron bluetooth enabled DCDC charger as they get better reviews from people who use them extensively and you can monitor the charger from your phone.


The other option if you don't want to spend the $'s you can get a portable solar "suitcase" type solar charger. About the same price as a DCDC charger.

 

[Jack]

The Renogy DC-DC requires a sense line to detect engine running. That's an extra wire (18 AWg or so) from the Hawk to the truck. The upside is that the 10 AWG factory wire from the Hawk to the truck will handle the 44 A (this is DC and the insulation is rated for the higher current - see rando's posts in https://www.wanderthewest.com/forum/topic/20835-4awg-from-the-factory/

The Victron DC-DC 30 A can sense engine running without an extra wire. However, with the 10 AWG, it often cycles on and off every few seconds my experience and see pawleyk post in the same link above.

The solution is to upgrade the wiring from the Hawk to the truck to 8 AWG (works for me) or 6 AWG wire. Or, like the Renogy DC-DC, run an extra wire to sense engine running. The Victron offers both "smart" sense and wired sense.

In either case, you will need to replace the thermal breakers with a 40 A or 50 A breaker. There is one near the truck battery and one in the Hawk, near the battery isolator.

 

[lostcreek]

Addressing the sense wire: with a Renogy it's not necessary to run an extra ignition-on sense wire from the engine if you already have (or will install) some other manual and/or automatic switch (relay, solenoid, etc). I have the Renogy 20A DCDC and spliced a short wire from the incoming positive at the device to the sense terminal. I use a Redarc solenoid in the engine bay, in addition to a toggle switch at the DCDC (usage depending on when solar is inadequate).