Dual battery

Just kinda looking around found some forums and read them but I didn't see any good diy options for a dual battery setup in the hood of the 1st gens without spending hundreds on a bracket...looking for some other options before I go and decide to do the battery box route in the bed of the truck

 

That's the cheapest https://www.tundras.com/threads/lets-see-your-caps.16054/page-58#post-3546285

 

I did like @evanhmn 's setup https://www.tundras.com/threads/wha...-gen-tundra-today.2558/page-1900#post-3504865

 

Definitely is the cheapest but curious the cheapest route for in the engine bay cause I think that'd be the best route overall for what I want but yeah it looks to be the battery box in bed is the best for atleast V1 of my buildout lol

 

I like that too and what I wanna do eventually but font really have access to more than basic tools so I don't have means of fabbing up a whole battery tray

 

Excuse my ignorance, but what is the purpose of having two batteries?

 

Extra power to run auxiliary for fridges, winches, ac/heaters whatever without killing your starting battery pretty much necessity for overlanding or you could go solar generator route like jackery but they are pretty pricey too

 

Ahh that makes sense. Right on.

 

I would think you could fit one of these marine style battery brackets over on the passenger side around/behind the power steering fluid reservoir

$16 Attwood 9091-5 USCG-Approved 27 Series Adjustable Hold-Down Marine Boat Battery Tray, Black

https://www.amazon.com/attwood-9091...UE9rRXcsDK0qVQ47B18_dNzZY9NFLMzRoCxb8QAvD_BwE

 

ABS was optional on the 2000-2002 Tundras. If you don't have ABS (or have deleted your ABS), then a second battery can fit where the ABS pump/module would normally have been mounted.

 

Can anyone post a setup of their duals on the passenger side engine bay and what was needed? Or maybe a step by step? Thanks!

 

I avoid dual battery setups, they always seem to have issues when it’s the worst time.

I run a goal zero yeti, it’s portable, charges quick with solar or 12v. And if it fails it doesn’t leave you stranded.

An Odyssey group 31 has a huge reserve capacity. I personally try to keep my battery system simple.

 

Thanks for liking the setup. I've seen some more questions about fitting a battery into the engine bay so thought I'd provide some more pictures. I've also attached a relatively detailed writeup on how I went about setting it all up. I'm no @shifty so excuse me if my writeup is lackluster. Hope this can help someone:

As far as what you need to do the actual wiring and whatnot, I would read through this article and follow the directions/materials used and go from there. I used the diagram in that writeup and followed it to a tee, so I'm not gonna walk you through what you need to buy and stuff. If you're still confused on what to get, lmk and I can help you out then.

The hardest part of the whole setup wasn't the wiring at all(I'm pretty novice to electrical work), but rather finding a battery tray and battery that works for you. I opted for an Interstate Deep-Cycle RV/Marine Battery, but that's mainly just because I'm a Costco member and it was a cheap $80 battery. You can research RV batteries to use and determine how much amperage you need. This can be done by just adding up all the power use of the devices you plan on running(fridge, lights, charging station, etc.) and then checking that the battery you'll be using can run those goodies for a decent amount of hours without the truck being turned on. I'd emphasize googling and looking around at how to determine how large of a battery you'll need, as detailing how to do that in writing is challenging for my small brain to do. This is a good article.
Now for the actual setup of the battery in the engine bay. What I did was disconnect my power steering fluid reservoir and ziptied it to my valve cover to get it out of the way. Make sure it is tied up somewhere and not just dangling. I then arranged my battery tray as tight as I could in the rectangular space, making sure there is enough room for the actual battery to fit, as well as making sure the connectors on the battery don't stop the hood from closing. This is where a tape measure is a vital tool. Then, I drilled 3 holes in a triangular pattern through the tray and through the wheel well, stuck three bolts through, and locknutted those bolts on the other side along with some threadlock for safe keeping. I then dropped my battery in, arranged it how I liked it, and mounted it to the tray. At this point all I had left to do was arrange my power steering and fab up a little metal piece to hold it upright in a good position, and not too close to where any high heat might melt any hoses. All I did to mount the fluid reservoir was cut two tiny triangular pieces of steel, bolted one to the other, and then bolted the whole thing to the battery tray.

I've had this setup for a few months now and It has served me very well. I wired up a 12V Car charger with an outlet to the battery and ran it into the back of my truckbed where I sleep. I've also put up 4 LED light strips back there too. I've charged my phone and laptop, had those lights running, and even ran a milk frother off it with no issue. The simple to follow wiring diagram gave me assurance I wouldn't kill my main battery, which was the biggest risk of all. I recall my first time charging freely and using the power I was dead set on having to jump myself in the morning, but that has yet to happen, and likely will not ever happen.

My main "warning" to you or I guess word of advice that I think you'll probably know is that because you're jerry-rigging your own battery tray and setup it's likely gonna be a PITA. I ordered the wrong size tray and isolator and had to return it which extended my project by a few days. I also can't tell you how sore my back was after lifting and setting down that battery trying to test fit everything again and again while kneeling on my radiator and headlight Then having to cut off these tiny pieces of metal and drill holes through em to get it all to fit... It was a pain at the time, but like with every project on our trucks, once you've got it finished it's such a good feeling to know you made something and learned something.

Links to the tray and isolator I used:

$24 THEPRO Battery Hold Down Tray Kit, Corrosion-Resistant Steel Storage Battery Holder Adjustable Bracket Clamp for Car, Boat, Marine (23cm Bolt with 28cm Battery Tray)

https://www.amazon.com/gp/product/B09DL1GK8N?ie=UTF8&th=1

$38 MaySpare 200 Amp Mobile Audio Continuous Relay and Battery Isolator High Current Relay 12VDC

https://www.amazon.com/gp/product/B085WRQW72?ie=UTF8

The other items you need like wiring, cable ends, etc. are all pretty general so just get what's in your budget. I provided you with the tray because I know it fits on my truck, as well as the isolator just because it's something I F'ed up on ordering the first time.

I'd also keep in mind, at least for me bc I live in CA(not sure of other states or countries), that if you go and buy a second car battery and it doesn't fit you can not return it - so make sure you're a little anal about measuring that battery!