Dual Battery Setups! Let's see them! Multiple Batteries Thread!

I left the isolator in line with bcdc. Works like a charm. Agm prior to bcdc 13.1v after 14.4-14.6

 

Finally hard mounted my components with an upcoming trip out to the high desert. I have a future need to run about 600W off the inverter and sized things for that, and to be able to charge at 40A. This setup consists of:
Bigbattery 170Ah "Owl" they call it now

$184 Renogy 40A DC to DC On-Board Battery Charger for Flooded, Gel, AGM, and Lithium, Using Multi-Stage Charging in RVs, Commercial Vehicles, Boats, Yachts, 40A

Renogy 40A DC-DC charger
Giandel 1200W inverter
2x80A, 1x70A breakers
Blue Sea isolator (not needed as the charger isolates when off)
negative terminal block
Renogy monitor/display
a bunch of mostly 4ga, copper lugs, etc.

If I add solar, Renogy has a nice 50A combo charger/charge controller I can swap in. TBH the Bigbattery acts well as a buffer for the inverter while mobile and has enough capacity for a few days of stationary needs for me so solar isn't compelling. I was running a small fridge, a heated sleeping pad, led strips and the water pump and used about 10% of the battery by morning on average.

This is a shot of things mostly assembled before final tidying up and securing the battery. The back seat platform I made for the dog and storage hides a lot of it.

 

I've decided to upgrade to a 12v fridge for next season, so a dual battery setup is now in my plans. I read about 100 pages from this thread and definitely found some good info. I currently have a group 27 agm battery up front and plan to add a second agm somewhere in the 80-100 Ah range in the bed. I've narrowed it down to either the CTEK D250SE or the

$465 Redarc BCDC1225D REDARC 25A in-Vehicle DC to DC Charger with MPPT — Dual Input for Solar & Alternator Charging, Green Power Priority - 12 or 24V Battery Charger Suitable with AGM, Gel, Lithium LiFePO4 Batteries

Redarc BCDC1225D for a charger in case I decide to add solar down the road (I do wonder how effective solar is here on the east coast with all of those tree things). I plan to place the charger on the back wall of the cab on the driver side. Reading between the lines of the CTEK manual, it appears they don't want the wring from the charger to the house battery to be longer than 6ft. I probably would end up having a run of about 8 ft. Anybody have a setup similar to this with a run longer than 6 ft?

 

I havent read my manual yet, but im planning on having mine mounted in the bed, and running the wire to the engine bay. I have some 8 awg wire that im going to use for that

 

It shows wire requirements for runs of 2, 3 and 6 ft, but nothing for longer than that.

 

Im sure if you use the appropriate wire size, you could mount it anywhere. I have the CTEK D250SE

 

I will probably run 6 awg for input and output no matter which one I end up going with.

 

Im modeling off of this. Been collecting all the tools for a while now

 

This is how I read this diagram.. the 6ft marking is for the out battery (second battery). A (IN battery and solar input) can be up to 30ft, which is the house battery. Basically it needs to be very close to the second battery, which is the same as Redarc

 

That is also how I read those instructions too. The Redarc ones say to mount as close as possible to the second battery but also say that all wire lengths given (up to 30 ft) include wire to the second battery. With all that being said, I'm still gonna run 6 awg and don't think that an 8 ft run should be an issue.

 

Tidy up my ass LOL. That's beautiful. Outstanding and professional install. Thanks for sharing.
Zim

 

Should the solar, house battery, and wire to the blue sea fuse panel have a breaker or fuse? When using the CTEK D250SE?

 

General rule of thumb; always add a fuse within 12" of the battery, whether going to the blueseas, controller, ect...

 

This is different setup, but same principles. I believe solar should have an inline fuse near the panel as well.

 

Another question, what size? I have 2x 100w solar panels, the CTEK is a 20A charger, and my blue sea fuse panel has 6 spaces, but only 2 things running on it (and not constant)

 

Yes.


And maybe yes. I did, but I'm an overthinker and figured it would be a safer and better idea to add a fuse for a panel.

Makes sense.

For solar, I'd say 20A.

For the panel, depending on what are you planning on running in long run, 60-100A maybe?

 

I agree, except maybe a 30a fuse for the solar and probably 60a to the blueseas.

 

The blue sea is running bed lights and a fridge. I am not running an inverter. I may add more lights, but not more than 4 to fill up the blue sea

 

That's fine, the 60a is for the entire blueseas panel and then you will appropriately fuse each accessory at the blueseas panel, like 10a for the fridge, ect...