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

Which battery would you guys recommend hooking up my winch and ARB twin to? The starting battery (X2 27F) or the aux battery (X2 group 35)?

I have a Redarc BCDC.

Both accessories will only be used while the truck is running, so I am thinking the starting battery is the most practical to hook them up to, yes?

 

Starting battery. They draw a lot of power and wound kill the other battery after a few hard winch pulls.

 

Thanks for the advice, I think I have a pretty firm grasp on what I'm going to do. Off Grid Engineering aux battery tray by the fire wall, ML-ACR, two 100w solar panels, charge controller connected to the aux battery, blue sea sub panel in the bed. I think a 50 amp breaker with 3/0 to the rear should be sufficient to run everything. It sounds like the solar will be able to top off two AMG batteries to the proper voltage to prolong the battery life. The last few things I'm trying to figure out is what charge controller to use and where to mount it, where to mount and what gauge to use, and where to mount the sub panel.

 

I'd hook the compressor up to the aux battery. The winch can go to either one if the batteries are linked, but since the alt is directly connected to the starter battery and your overall wire runs would be shorter, I'd hook the winch to the starter batt.

 

Need some recommendations from you guys on my solar charger settings inline with my dual battery set up please.

I have the OGE Dual Battery setup, w/MCLR - Running on "Auto", (2) Group 35 Ody AGMs, and recently just hooked up a 130W Solar Panel tied to a Victron MPPT 75/15 Solar Charge controller direct to my aux battery.
What I am needing help with is utilizing the correct settings in the Victron Bluetooth app to optimize battery charging from solar.

Battery specifications:

Victron App Settings screen:


Based on my batteries and running the mclr on "Auto", what should I set the the following to:
(Battery Voltage) - I figured 12v but technically the MCLR being on Auto is transferring charge between (2) 12V batteries.. = (24) volts
(Max current charge) - 15A I figured this is the max and why the controller is the 75/15 model. But should I reduce this down from 15v?
(Absorption voltage) - What would you recommend?
(Float voltage) recommendations?
(Equalization voltage) recommendations?

I have tried to do a ton of internet research but am getting frustrated.. Any help would be greatly appreciated.

Thanks,

 

Absorption and float will vary depending on the temp.

this is a good reference
http://www.4xspower.com/Dseries-Instructions.pdf

 

The engine bay temp? or Temps seen at battery during charge?

 

An mppt controller is intended for use when the panel Vmp (roughly its normal operating voltage) is substantially higher than the battery max charge voltage.

In this case, the Vmp ~ 18 and the Vbat max is ~ 14-15 volts, so the 3 volt differential is marginal. Those are really for when you have 2 panels like that wired in series.

I know that people like the cool victron phone application, but a better solar charge controller for this application is a pwm controller - example bogart enginering.

It isn't completely obvious, but what these agm batteries need is not only total watts of charging, they need a lot of charging time. The pwn controller will operate on lower light levels, so charging starts earlier and ends later in the day.

The effect is even stronger in areas that have overcast / diffused lighting. I have done the math on these systems and used mppt controllers when the calcs all said it should work - and then ended up replacing some mppt controllers on customer projects. You have to be watching the dials to really appreciate how panels and controllers really behave in poor lighting.

As far as settings for the victron, usually you can use the default AGM settings as the ods are very well behaved.

If you want to dig deeper, then just use the settings in the battery technical manual.

 

Haven't learned much yet. Relocating a dual setup under my bed in my 5vz 1st gen and only need the primary vehicle battery connected at the beginning for getting out of my driveway. Any resources for building / sourcing wire / terminals / solder etc. and how to move primary starting battery wires for relocating?

Few things I've sourced, but not married to if there's more cost effective / similar cost but higher quality alternatives:

Battery Wire

$129 TEMCo 2 Gauge AWG 25 Ft Black + 25 Ft Red Flexible Pure Copper Made in USA Welding Cable Battery Wire - Heavy Duty Solar, Inverter, Car, RV, Truck

https://www.amazon.com/TEMCo-WC0180...NPKCX7B2KWY6&refRID=745972YGNPKCX7B2KWY6&th=1

Crimpers

WBHome Hydraulic Wire Crimper Battery Lug Terminal Cable Crimping Tool, 8 Dies, 12 Ton

https://www.amazon.com/WBHome-Hydra...g/dp/B0811VYCQ6/ref=psdc_553392_t1_B00KS4R3PI

Terminals

$9 SELTERM 10pcs 4 AWG - 3/8" Stud - Battery Lugs, Heavy Duty Wire Lugs, Ring Terminals, Battery Cable Ends,4 Guage Terminals, UL Bare Copper Eyelets Electrical Battery Terminal Connectors

https://www.amazon.com/SELTERM-Gaug...DCDRHND1HPZ&psc=1&refRID=KKH3J7PQ6DCDRHND1HPZ

 

My Victron mppt has been awesome. Even on cloudy or rainy days I still get enough voltage from my panels for a decent charge rate. The phone app is fantastic and after using it I wouldn't use any other controller that didn't have that feature. Using 2 100watt panels, my controller really only bulk charges for part of the day and usually float charges for a greater part of the day as the batteries are already full. My main power draw is an ARB fridge/freezer.

Also, I live in Colorado so we do get a decent amount of sun.

 

First time testing out Gunkote (titanium) on the Off-Grid Engineering dual battery trays and Overland Equipped fuse block bracket. Also, put on a few layers on those two raw front bed hooks. Little bit of a sloppy job but good practice before working on the AR15.

 

Man that looks good

 

After over thinking the heck out of it, I gathered and finally installed my dual battery set up. I also cleaned up wiring under the hood. It just had to be done...
I opted for Northstar 31A AGM battery, Ctek D250se DCDC charger, and topped it off with 100W slim solar panel.



Done all this work in order to run a 75qt fridge...

 

But soooooooooo worth it.

 

Let us know how important the solar panel is to overall package. I've got basically the same thing and have debated the need for a panel as I generally move every day anyway and the fridge is such a low draw.

Also, could you take a shot of the 2nd battery from a little further out so we can get a better idea how you laid it out? Did you have to forego any functionality after the install?

Nice clean work.

 

Thanks! Took a WHILE to wrap all the wires in those sleeves!

With child seats and all the crap, that's the best I can do


Battery is installed on a group 31 sized tray and tied down with a strap i got in HD. And only downside I see right now, I lost behind the seat storage.

As for solar, hmmm... When running fridge/freezer combo it can draw ~5Ah, so I'd get approx 11 hrs out of the battery. Of course finessing the hell out of setting, it is possible to almost double that. Sooo I figured adding solar would only help, not harm it.
Also, when not running the fridge, it actually topped off my starting battery! So there is that.
Is it really important, maybe not. But also I don't have enough real life data to argue it either way.

 

Not sure if I dropped this in here, but ....here! Lol.
Zim



So I'm still in the design/build mindset. I fab'd up this mount which I like and might keep. I've only drilled 4 holes in the truck, none in the bed, and no one will ever see 3 of them...lol. Does not take up much room, and it's neat and clean to a extent. I can store some things under, and over if I want. Already went camping, and just using the lights we had plenty of power. Charger will probably not live there as I charge my golf cart too. Just playing around and having fun. Film at 11.
Zim

 

I just purchased a

$458 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 DC DC charger. I will be installing the 2nd battery in the back of the rear seat. I am sourcing parts for the setup, 6 AWG cables, 40a breaker, etc.

Does anyone have a wiring diagram where to place the breakers and what size? I am going with breakers instead of fuses.

 

Manual is listed on the page: https://cdn.shopify.com/s/files/1/2...ut_Instruction_Manual.pdf?7204406381448510702

Fuses/breakers should be as close to the battery/ies as possible. Looks like they call for 40A fuses.

 

Alright so i have a dual battery set up and i have the accessories running off the aux battery but it only allows this when the isolator pops on since i have the cole hearse one. anyway around this without breaking the bank?