New dual battery setup going in

[RoundOut]

I got almost 92K on my original battery in 4 whole years. Not bad for a factory job.

It died Tuesday and I decided to jump into dual Optimas (Red top from Sam's Club, Yellow top from 4 Wheel Parts) and a Painless dual battery solenoid kit (also from 4WP). The stock 1Gen Tundra V8 Access Cab has room for dual batteries, but must be heavily modified to make them fit. I started down the road to replace my battery cables completely, and then punted, after seeing how deep into the engine (read: near the exhaust system) I had to plunge. Hopefully, someone can either use or improve upon my experience. I'll describe my setup as best as I can in the next few posts.

After a parts gathering trip to O'Reilly and Home Depot, it was time to get started. Good thing my buddy, Tom had some time today, as he endeed up designing and welding up my dual battery tray for me.

Status:
Duals installed, but only operating from the Red Top. I have to pick a location for the controller switch for the isolator and therefore, have yet to finish the job. I want to make the shortest wiring run possible, so I need to pick its home carefully, especially if I have to cut something. Maybe finish this tomorrow, but surely by the weekend.

Pics attached:
1) We cut 90 degree notches out of one side of a piece of angle iron, then bent the sides together to form the rectangular tray. Later, we welded a center support lengthwise across the middle. The batteries sit side by side oriented where the side terminals face the passenger side of the vehicle.
2) I used a die cutter to trim this piece from the OE battery tray, allowing our new tray to sit where it was.
3) A little black spray paint to seal out rust.
4) I used a piece of strap to secure the relay/fuse box by removing all four or five of its mounting locations and using this one, and one other on the side a bit (about 2") toward the rear. The new welded rectangular tray sits on top of the OE plastic battery tray and is secured at the bottom on the original bolt hole for the fuse box, where this strap also is secured.
5) Front view of batteries installed. DON'T LAUGH, it's only temporary!
6) View from passenger side of batteries. Note that I re-used the factory j-hook and battery clamp, extending it somewhat. Again, this is only temporary.

 

[devinsixtyseven]

:box: :rockon:

Lessee some pics!

 

[RoundOut]

Status update 1

PICS STILL FORTHCOMING, sorry guys. I hope this turns out as good for you as it has been fun for me (with the exception of the non-upgraded battery cables fiasco).

I love the dual posts that the Optimas provide! They come with a pair of top posts and a pair of side terminals. Were it not for the side terminals on the Red Top, I would not have been able to re-use the factory positive harness without stressing it severly. As it was, I unscrewed the factory eye connections on the positive harness from the positive terminal connector and screwed them into a side connector on the Red-Top. The end of the negative factory harness was able to be cut off and clamped into a side terminal mount, too. I snipped the cheesy 4", +/- 14 guage chassis ground wire from the negative harness and used some left-over 2 guage black battery cable to make a short chassis ground from the Red-Top's negative post on top.

With some additional left-over 2 guage battery wire, I am doing a jumper cable mod that I have always wanted to do. The local 4WP store that sold me my Yellow-Top, gave me a GREAT deal on a Warn 175 Amp Quick-Connect kit and dust cover. I got the $36 part for $26 and he threw in the dust cover (regularly $15) for FREE. SWEET. This allows me to put a front-end-outside-the-hood-connection for jumper cables on the front bumper. I will add a rear bumper connection to this setup when I get a chance to build my new rear bumper with spare-tire swing-out carrier.

So, here is where we are so far...

Dual batteris in place in factory single-battery location, using a fabbed up mounting tray/bracket and clamp setup. We re-used the top clamp, hook bolt and nut (used on the side closer to the passenger) from the factory setup, and added a 1/8 threaded rod in between the two batteries, plus a perforated strap from the side farthest from the passenger over the top of the Yellow-top, connecting to the end of the factory top clamp. We re-used the plastic factory tray to prevent scratching of the paint on the inside of the driver's side fender.

Red-Top Connections:

• Side Terminals
  • Positive - Factory wiring harness connections, positive jumper cable
  • Negative - Factory wiring harness connections (ex the 14 guage chassis ground), negative jumper cable
• Top Terminals
  • Positive - Positive primary battery connection on Painless isolator
  • Negative - new beefy chassis ground

Yellow Top Connections (Top terminals only)

• Positive - Positive auxilliary battery connection on Painless isolator
• Negative - Chassis ground
• Planned accessories to connect to Yellow-Top:
  • Rear flood lights (ordered from Northern Tool today) - to be located in new rear bumper - My idea for this should be very functional. I'm planning a diode-based wiring to allow automatic backup service when in reverse from primary battery, and in-camp rear flood service from auxilliary battery by throwing a switch.
  • Side flood lights (ordered from Northern Tool today) - location t.b.d.
  • Refrigerator
  • PC power supply
  • 12 volt outlets at rear of bed
  • Mobile Ham radio
  • CB Radio (ordered from Northern Tool today and plan on installing in location of factory ash-tray)

I still need to wire the control harness through the firewall and decide where to mount it inside the cab. I will probably avoid cutting any visible holes, as ultimately, with my planned lighting and accessory power from the Yellow Top, I think I will purchase a 1-DIN AM/FM/CD/MP3/XM radio and use the lower DIN slot for my accessory switches/indicators. I wonder how many switches I can fit in there - I bet at least 6, maybe 8?

Thinking ahead with future plans for an auxilliary fuel tank, I will probably get the door-pillar guage pod for an auxilliary tank fuel guage and refrigerator/cabin thermometer. I cannot remember, but if there are three pods on the Tundra pillar pod, I will get a transmission fluid temperature guage, too.

If I use the factory radio slot for the switch panel and a door-pillar guage pod, this setup should look VERY clean and almost stock in the dash. Now, if I could just afford all the other accessories, LOL.

Update: I finished the jumper cable mod and bought the parts for the switchplate that I will put in the lower DIN of the factory head unit. I still need to get a metal or plastic plate, but may try something I saw at Wally World, an aftermarket fitment/plug kit for new head units. If this kit has a lower DIN face plate, it may be much easier to use it than fabbing up a clean metal plate. We'll see.

Pics:
1) Warn quick-connect after being painted black to match the bumper
2) 2# cables run through expanded metal of my Tough Country front bumper
3) Quick-connect mounted in place
4) Cover for quick-connect, attached with a small cable to a bolt just inside the hood so it doesn't make legs.
5) Plugged in, ready to jump-start some poor soul's dead battery.

 

[devinsixtyseven]

Sweet! And only six weeks til we get to see it in person.

Notice any difference with the extra weight up front?

 

[RoundOut]

Notice any difference with the extra weight up front?

I still have my skid plates off, so it may even sit a bit higher, right now. That will be short-lived, though, as I'll get them back on soon. I still have them off, because I have not finished the isolator wiring yet, and may still do the factory battery cable replacement.

Plus, when the body shop fixed my front bumper, they busted off two of the welded nuts that hold it on. making it much harder for one guy to mount up the front skid plate.

 

[RoundOut]

Internal control location decided

I have not finished this install because I was undecided on what to do with the switch for battery control, until I am able to do my head-unit swap, opening up room for permanent switch locations. Well, I think I know where it will go...

In the 03 Tundra SR5 Access Cab, there is a hidden compartment in the console up close to the dash. From the non-Tundra owner's perspective, there is a tray that holds stuff. If you know it is there, there is storage under it for a wallet, a couple CDs, or whatever. I keep miscelleaneous stuff there, that I never even think about.

Knowing I am someday going to replace the head unit and put switches in the lower DIN location for a factory clean look, I was reluctant to cut a hole for the dual battery controller switch elsewhere in the cab. Putting it down in that secret compartment is the perfect answer. When I am able to do the radio mod, the wire length will be about right, so that won't be a problem either.

Now to get the time to finish the mod...

UPDATED:

I used the above location to mount my control switch for the battery isolator switch and indicator lights. Pics below:

1) Inside the hidden compartment at the front of the console. Now you see it.
2) Now you don't.
3) Backed up so you can see the whole arrangement of the console, including where I mounted the CB radio. I still need to plug that small hole to the left of the radio for a totally factory clean look. I'll work on another picture when that's done.

 

[RoundOut]

OK, this will sound a little dis-jointed, but all the following is related, so stay with me...

I got my new rim today... It is a Procomp 8069, the same one that Wheeler's sells for $125, for $100 from Discount Tire. I had the scratched up one, mounted on my spare (the best of my last set of BFG's). Now if I have a flat, I have a matching tire to replace it with.

Interestingly, though... when we pulled off the spare, there was a spot on it where the exhaust pipe on the drivers side passes it closely and had melted the rubber a bit. I was a bit bummed, cuz it had never been driven on and I was hoping to get a decent $50 or so. Maybe I still can.

Notice any difference with the extra weight up front?

Wow. After settling, my driver's side (where the dual batteries are) is really sagging. I am going to work hard toward getting ready for my rear bumper/swing-out-tire-carrier. When the swing-out is ready, I'll have the matching tire for it, anyhow.

Until then, I think I'll fab up a heat shield for the spare, though. I'd hate to melt my matching spare.

I figure getting the batteries out of the engine compartment will REALLY help the sag, since it is probably close to 110 pounds in the far front left, helping weigh it down. Putting that weight right behind the rear axle where the present spare is, will REALLY help toward balancing my truck front to back, besides the benefit of lower center of gravity.

I probably will mount some terminals on an insulated hard point of some kind near the existing batteries and run some HUGE 2/0 or biggIter positive cables to the main and auxilliary batteries in some wrapped wire loom along the frame rails. The way my dual system is configured, I can get away with just one negative cable as a loop (because I am anal that way), increasing conductivity that the frame would provide. That will also help reduce the rogue RF from the cables. I'll run the power wiring for the rear bumper additional backup lights in the same loom.

I am VERY happy with the system, now that it is installed. :jumping: The only problem is, I don't have many (read: any) loads on the auxilliary battery yet. It'll be great for a no-cable jump start, if I needed it though. If I have to jump anyone else, I'll easily be able to do that without opening the hood, too.

 

[RoundOut]

Pics --- Finally.

I updated posts #1, #3, & #6 to include pictures of the various finished install. Later today, if I get a chance, I'll post up a description of how the Painless Battery Isolator kit works, and what I still plan to do to it, if it is feasible. Enjoy.

 

[jim65wagon]

Sweet! The whole install looks good. If I add much more in the way of electricals I may need to print this!

 

[flyingwil]

Looks great!

 

[Willman]

I like it RoundOut!

Just an idea....Heat sprink works great on all your cable ends and gives it more protection from the weather!

Keep up the great job!

 

[RoundOut]

Just an idea....Heat shrink works great on all your cable ends and gives it more protection from the weather!

Done!

 

[RoundOut]

Later today, if I get a chance, I'll post up a description of how the Painless Battery Isolator kit works.

Well, that day seemed like about 25 days. LOL

Here's how it works...

• When the switch is in the center position, neither the green or red lights are on, and the batteries are isolated, just as if the second battery didn't exist.
• When the switch is in the left position, the green light comes on when the key is in the "run" or "start" position. In other words, when the key is in the "start" position, the batteries are combined to offer extra starting power, and when the key is in the "run" position, both batteries are being charged by the alternator. Also, note that when the key is in the "accessory" position, the batteries remain isolated. This is so that one doesn't drain both batteries if you leave the vehicle, and your dome light or radio remains on draining the primary. The secondary battery remains in a backup position.
• When the switch is in the right position, the batteries are combined at all times. This is ideal for a self jump-start, but I cannot imagine using it for much else.

Painless recommends using the primary battery for ALL accessories, including winches and high-energy-consuming stereo amplifiers, for example. This is so one always has a good back-up.

I leave the switch in the left "green" position almost all the time, so that both batteries are getting charged. At present, I don't have any loads running off of the secondary battery. If I take Panless' advice, I won't put any on there, either.

After giving this much thought, I am beginning to lean toward switching the positions of my red and yellow top batteries, allowing all accessories to be powered from the deep-cycle yellow and using the red top as the backup. Would anyone like to chime in and offer their expert opinions on this?

 

[RoundOut]

Next steps to finish this mod

I would like to have the ability to check voltage on either battery. BajaTaco has a nice setup for this, and I have been looking for a voltmeter (not too diligently, as there are plenty of other things to do). I can wire that up pretty easily when I find one.

I also think that it would be prudent to have a "smart charging circuit" of some kind in line to prevent "overcharging" of the secondary battery. IIRC, BajaTaco has one of those, too. I saw another similar system over on Mud and bookmarked it. I think the one on Mud used the "service alternator" feed from the fuse box to determine when to apply a charge current to the secondary battery.

I'll update this post in the near future with links and definite references.

One final project that is not on the critical path right now, but is definately needed, is to relocate the batteries. I have began to notice a tilt in the front elevation of the truck on the driver's side, and I choose to believe it is not from the weight of the driver, but rather the weight of the batteries that high and forward. I just listed my Tough Country rear bumper for sale on TundraSolutions. If I get it sold, that will open up the resources to build my custom rear bumper with swing-out tire carrier. Moving the tire out from under the bed, will free up the perfect position to have 120 pounds of batteries -- centered right behind the rear axle under the bed. I'll string four cables of 2/0 AWG (two red & two black) the fifteen or so feet up to the present battery location and mount some beefy terminals there to cleanly tie everything back in, as well as locate a chassis ground under there.