Help with Dual Battery setup.

SnoRnR

New member
Hi,
I am in the process of purchasing the parts for my dual battery install. I installed the Shrockworks Dual battery kit. Toyota 4runner 2019.
My setup will be:
Odyssey PC34R-1500 68AH (34Ah usable)
Redarc BCDC 1225D
Blue Sea 6 Fuse Block
160w Renorgy Flexible solar on top of RTT
Deployable 100w solar blanket to supplement above when at base camp.
Switch Pro-9100 (Running AUX lights/loads and controlling compressor)
Blue Sea 12v USB/cigarette outlet in trunk.

Solar should supply 6-8 Amps for 6hrs = 36 to 48amps
Once static at camp will deploy 100-120W blanket ( 6-8amps)
Questions
1) Redarc states 6AWG wire for our cable lengths. (Would it be better to use 4AWG?) The Redarc will be mounted directly on top of AUX battery so seems overkill 4AWG. Also, states 40amp MIDI fuse for low resistance (Heat). (These things are huge) Would a 40amp circuit breaker or terminal mount fuse be ok?

2) I want to run 2 pairs of cables to the rear for the fridge and Blue Sea 12v/USB. The fridge will be direct to battery via Anderson connector in rear. Is 10AWG good for the fridge or overkill? Hoping for lowest amp loss/most efficient.

3) If I use 10AWG fro the fridge will it be ok with a 50amp Anderson connector? I know Anderson is made for thicker gauge possibly 6AWG.

4) Switch Pro will be mounted on the other side of the engine bay from the AUX battery. What size wire should I use? 2/4AWG? I know it's rated to 125A but would it ever draw that? Going from Blue Sea cable recommendation chart 2AWG would be required.

5) I will be making a mounting bracket for the top of the AUX battery (Mount Redarc BCDC plus 6 fuse Blue Seas block) Will any plastic board be good for this? Looking at HTPE or Acrylic on Amazon 1/2 inch thickness. Never done this before so don't know the tolerances (strength/heat) of these materials.

6) What gauge and how many wires can you fit down the windshield trunking?

7) Anyone have any ideas for a connection terminal for the solar (Plastic section at the base of the windshield corner) For connecting Anderson (solar). I may just run the cable into the hood then have Anderson connectors under there.

8) Is it ok to earth the AUX battery to the chassis/frame? Or should I run it to the starter battery? What size cable should I use for the earth?

I am thinking 12AWG to the Blue Sea 12v/USB outlet, mounted in the trunk.
 

shade

Well-known member
Welcome to ExPo! ?

If the Blue Sea fuse box will be located outside the cab, I'd suggest using one of their SafetyHub models.

5) For your mounting material, 1/4" polycarbonate sheet will work, but 3/8" or 1/2" can work, too. You can carefully heat and form 1/4", but thicker sheet would be difficult to form. Don't use acrylic sheet; it's prone to cracking. I don't think HDPE is as thermally stable as polycarbonate, so you may want to avoid it.

Many of your wiring questions can be answered by using the Blue Sea Circuit Wizard.
 

rayra

Expedition Leader
'Starboard' / HDPE2 will work fine, IIRC its melting point is in excess of 400F. Any piece of HDPE2 cutting board would suffice, for what you are intending to do. And the stuff can be worked much like wood, for purposes of sanding or edge-routing or screw-holding.
 

shade

Well-known member
'Starboard' / HDPE2 will work fine, IIRC its melting point is in excess of 400F. Any piece of HDPE2 cutting board would suffice, for what you are intending to do. And the stuff can be worked much like wood, for purposes of sanding or edge-routing or screw-holding.
I was referring to dimensional stability, not melting point. I know people that have had problems with it swelling & contracting due to temperature changes. Polycarbonate can be drilled, sanded, sawed in much the same way.
 

SquirrelZ

Member
1. Heavier wire is more efficient at conducting electricity. As Shade pointed out, the Blue Seas Circuit Wizard will answer many of your questions. There is even a phone app which is super handy. As for the 40 amp fuse, I'd ask Redarc why they have such a specific recommendation on the fuse type. If you have the right size wire and fuse, nothing should be getting hot. I'd think that a terminal fuse block would work just fine....

2-4 and Blue Sea 12v/USB outlet in trunk. Use the Blue Seas Circuit Wizard.

5. Another vote of HDPE. Its worked fine in my applications.

6. Sounds like time for some trial and error.... Not all electrical cables are the same. If you buy Blue Seas 10 ga wire its almost undoubtedly going to be much bulkier than crap that you buy at an auto parts store.

7. Your question isn't clear. Are you asking about what type of connector to use? How to fasten the connector in place? Or where to place it?

8. I have a cable back to the main battery for my aux battery. Use the the same size cable for the ground as for the positive.
 

Justin Cook

Member
When using Blue Sea's cable gauge calculator, please be sure to enter round-trip distances; unless they've updated it since the last time I was there, they forget to specify that (example: if your fridge is 10' away from your battery, the total circuit distance is 20': 10' POS, 10' NEG). This is a critical detail that many calculators forget to mention.

In regard to the Anderson plugs, you can get them in different gauges (it's the gauge of the crimp pin that changes, and the pin slides into the connector and clips into place). For the SB50, you can get the crimp pins in 6, 8, or 10AWG: https://powerwerx.com/anderson-sb-connectors-sb50-50amp

Important note: differently-colored connectors do not fit together!! A blue SB50 connector will only mate with another blue SB50, it will not mate to an orange SB50 (or whathaveyou). I once ordered a variety pack thinking I was going to use color-coding on my components and quickly discovered this unfortunate detail.
 
FYI, your panels will put out rated amps only when pointed directly at the sun, on a sunny day with no clouds. On cloudy days the amps go way down. Make sure that you take that into account.

I’ve got dual batts on two vehicles and like them lots.

FYI2, I’ve used FLA, AMG and LiFePo4 batteries. I like the LiFePo4 best...I’m never in cold temps though.

Follow the wire guides and use solid connections. Tony Candella sells great lugs and excellent wire in 8 gauge and thicker.

https://ceautoelectricsupply.com/in...ets-large-gauge-butt-connectors/mega-eyelets/
 

shade

Well-known member
When using Blue Sea's cable gauge calculator, please be sure to enter round-trip distances; unless they've updated it since the last time I was there, they forget to specify that (example: if your fridge is 10' away from your battery, the total circuit distance is 20': 10' POS, 10' NEG). This is a critical detail that many calculators forget to mention.
In the mouseover text for the Length of Conductor (feet) box, it mentions to use the total length of the conductor - supply & return.
I think it would be better to have it displayed constantly. As you said, I'm sure that has been overlooked more than once.
 

SnoRnR

New member
The positive is going through the DC to DC charger. Which is 8AWG. Should I use 8AWG for the ground or hight? I was thinking 2 AWG.
 

SnoRnR

New member
I am using AGM as we are in Alberta. Regularly see minus 20 to minus 40 c in winter. The panel wouldn't be our main supply. Just something to tide us over on days with activities. We would also be driving those days so the DC to DC would help. I will invest in an additional solar blanket that I can deploy facing the sun once we are at camp.
 

shade

Well-known member
I am using AGM as we are in Alberta. Regularly see minus 20 to minus 40 c in winter. The panel wouldn't be our main supply. Just something to tide us over on days with activities. We would also be driving those days so the DC to DC would help. I will invest in an additional solar blanket that I can deploy facing the sun once we are at camp.
Some folks in the GWN have found that positioning a panel vertically gathers photons better than more traditional orientations, especially with snow reflecting the light.
 

rayra

Expedition Leader
That would be perfectly fine. But at 1/2" thick probably overkill. Unless you hit a lot of washboarded roads, even a 1/4" thick / thin piece should do. This is just to mount a fuse block over a battery, correct?
use washers both sides of the board, don't put the corner holes too close to the edge, or too close together, and you can fill it up with fuse block, DC-DC charger, etc.
I'd suggest doing a 'breadboard' prototype with plywood first, until your design is set, then copy / execute it in the HDPE.

Here's a neat calculator for optimum panel angle, lets you pic country, state, city and shows optimum angle for each month. Looks like near vertical really is needed for your area in winter. But too, that slant angle thru the atmosphere is going to reduce your solar efficiency measurably even if you get the optimum panel angle. So expect to not achieve the panel ratings. Might be as much as 15-20% below.

 
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