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

Has anyone relocated their inverter wiring over to their house battery ?

I’m kicking around the idea of connecting the inverter to the house battery so I can run it anytime without the key in the ignition

Thoughts ?

 

My Off-Grid Engineering dual side-by-side kit. It took a while but only because I'm so OCD and I needed to cut the cup holder for the dual voltmeter, ACR switch and a rocker switch that turns on/off the dual voltmeter. The kit was very easy to install and it looks tidy under the hood. It's not as neat as I'd like because I had to run extra wires for my dual voltmeters but I'll clean that up once I have more time.

I ran my winch to the starter battery and my Bussmann to the Aux battery for lights, CB, etc. Excuse the dirty engine bay.....
There was a small Dremel mishap to the right of the voltmeter and ACR switch I'm going to try and get some paint to touch that area up.

 

That looks slick, do you have a link to the voltmeter that you used?

 

Thanks...it was a good decision since I'll be adding a fridge to the truck next year. The dual voltmeter was from Air On Board (https://www.aironboard.com/online/dual-voltmeter-in-red.html).

ETA- it was super easy to wire. One wire from each positive post and then a ground. I ran two + wires into the cab and then used my switch to break the ground. The - wire is only about 6" inches long to a bolt under the cup holder.

 

Nice. I think ill be getting one of these

 

Updated my setup a bit,
was

to

Updated the post to show the model it was built from


Was able to get the air compressor hooked up and I really like the "SleeOffroad ARB Twin Bracket" it was a nice find with the help of another member. Have one spot left for the remaining electronics and with the weight of the battery and air compressor hope it helps with the Taco lean. Once it is all setup I will take it apart and powder coat all the raw metal. Now that I have the winch disconnect, I want to have two breakers for the battery. Does anyone know the max amps the start will pull? or do I just size it for the wire. My battery cables are very large so the truck will cook if something goes wrong.

 

This is the one I went with.

https://www.bluesea.com/products/7149/187-Series_Circuit_Breaker_-_Surface_Mount_200A

Even though it is labeled as a 200 amp CB, a quick look at the performance graph will show it is rated to handle up to 600 amps for up to 5 seconds before tripping.

This is the best of both worlds. It allows the amperage required to start the vehicle yet will still protect the assests in a dead short scenario.

 

Just make sure you only have wire that can handle that much load attached to it. If you add any accessories to the protected side of this breaker, I'd fuse them appropriately for the size of the wire used to power that accessory. This breaker will not protect 10ga wire.

 

On my setup that breaker is between the ML-ACR and the house battery. That is 1/0 gauge.

 

That will melt. 200a needs at least 2/0 wire. No jk.

http://assets.bluesea.com/files/resources/newsletter/images/DC_wire_selection_chartlg.jpg

 

1/0 will do just fine for an 8' run.

 

Really? Because the wire size/amp rating charts in my electrical reference books, and on the reputable websites clearly state the following:

1/0 stranded copper
150 amps at 75 degrees C.
170 amps at 90 degrees C.

1/0 stranded copper wire will not conduct 200 amps at any length.

 

What are the cranking amps required by our trucks, note being pulled over 4ga(maybe 2ga) wire, and most winches use the same gauge wire and pull 200+ amps



https://www.warn.com/95xps-winch-87310

 

I'm fixing to start planning my second battery installation. Do you have to place the second battery in the back left for a 3rd gen?

 

Fine. Then explain the charts.

 

Beats me, just saying people like Warn and car manufacturers must be in with the lizard people.

 

The charts are for constant load not surges, there are separate ratings for maximum operational and maximum ratings.

Same reason you can’t use Copper Clad Wiring or Tinned aluminum like you find in cheap jumper cables. If you hold them while someone is cranking you feel them heat up quickly from voltage drop. They are rated at even lower operational capacity. But they are designed for very short surges of power which makes them cheap.

 

Ok, that's the explanation I was wanting--the "why" of why something is.

But, going back to the comments by digiratus and k8md; it sounds like it will be a constant 200 amp load (yes/no?) Because, according to the charts, 1/0 is not big enough. (Not trying to argue; rather looking for answers because of my home LiFePo4 800ah, 400a, battery bank, and its wiring.)

Thanks.

 

Your math is incorrect. Amperage is equal before and after the split in a parallel circuit. You don’t add up the total amps from the battery bank. In each branch it is a fraction of the initial amperage before splitting. In series the amperage is the same from the battery in operational or surge capacity. Not knowing your setup I assume your math is incorrect. If you are utilizing battleborns in series to get a 48V system, you are still at 100 operational and 200 amp surge due to the limitations of their LiFePO4 design. In parallel, you are still 12 volt but much large amp/hr capacity yet still only 100 amps continuos and 200 amp surge for 30 seconds IIRC. It is printed on the side of their batteries. Hope this helps.

No, I am not an electrician. I am an infantryman. I have lived on many remote areas where we utilized smarter infantryman to hook up single and three phase generators and use backup solar battery banks. I am just finishing my solar setup now.

 

You don't know my setup, but my math is incorrect? Really?!? How the hell can you even write that???

My setup is this:
8x Winston LiFePo4 , 3.2v, 400ah batteries connected in 2P4S, 12v nominal. That's an 800ah, 10,240 wh battery bank, that is capable of being charged at 1200 amps continuous (what is called a 3C) and discharged at 1200 amps for up to 15 min., from full. The "recommended" charge/discharge is a rating of .5C (200 amps.)

This setup is charged by way of 300 watts of solar, and backed up with a 4000 watt generator &/or a 400 amp electric charger, connected to the main. It partially powers a home configuration (120v & 12v) until I can acquire another 24 batteries, at which time I'll go to 24v nominal--and be able to use smaller wiring.