Dual battery setup

Hey guys. I found this monster thread about dual battery setups but it seems to be mostly 2nd gens
https://www.tacomaworld.com/threads...-them-multiple-batteries-thread.295653/page-7

Anyone here in 1st Gen land have pics and info of their dual battery setup? I'm mostly interested in being able to charge things and run the radio and lights while camping without killing my starting battery. Maybe a winch eventually.

 

I started with a pair of optimas I got for free. I put them in the stock location.

I would not advise doing this.

1st- it’s a lot of weight in that location. I have at least one large crack at the top of my fender. My main support is bent so my head lights are all kinds of crazy. They’re adjusted as far as they’ll Go. The driver side points at the sky and the passenger side points at the ground.

2nd the optimas sucked as a starting battery and a deep cycle battery.

I’ve since upgraded my aux battery and moved all batteries into the camper I built. I also upgraded to a proper charge controller that also works off solar panels.
The new battery location puts the weight between the axles and it takes them out of the heat of the engine bay.

 

I just put together a dual battery and put the second battery in the truck bed. Have a battery isolator up front and a power cable running underneath and up through one of the truck bed drains

 

Which charge controller are you using? My only hesitation with going this route is the ease of being able to self jump with a typical Blue Sea ACR.

 

I have winches on both my 96 4X4 and my 98 prerunner and only use a single battery but then I am not doing sustained pulls like in a recovery situation.

 

I have the Columbia Overland kit.

I'm starting to get cracks in my wheel well and core support from all that weight on such thin sheet metal, so I can't say I recommend putting both the batteries in that corner.



If I were to do it again I would probably stick my aux battery or possibly both batteries in or under my bed.

 

I have a Ctek 250 either S or Sa.
For jump starting I just use jumper cables going from the camper batteries to the starter battery.
Even if I could jump via the charge controller I’d probably still carry jumper cables for other vehicles.

There are lots of options for charge controllers. I went with the ctek because I got a really good deal on it. Not because it was the best charge controller.

Edit: also the ctek is expandable. Although I have 200 watts of solar and 230ah of battery the base unit charge controller handles that just fine. Not sure that I’ll ever expand.
I’ll probably switch to lithium someday when the prices come down. In which case I’ll need a new charge controller.

 

I put a second AGM battery in my cab; nice side effect was that it allowed for some better storage/organization as well...

write up and lots of pics here:
MOAR Power, More Redundancy - Dual AGM Battery Install

​

 

I too thought of doing a dual battery setup. I'd like to explore getting a battery box mounted between the frame rails under the bed. A clean look but expensive due to some welding and fab work. The most likely setup would be in the bed with a metal box.

I'll likely wait till I have to replace mine with a newer model...

 

So to add a second battery, all you really need is the extra battery, an isolator, the cable, and a place to put it?

 

Pretty much. A dc-dc charger is better than an isolator. But I think an isolator will do the trick. Others may know better.

I used this stuff for cable. It’s pretty nice and it’s made in the USA. Actually about 2 miles from where I work.
TEMCo WC0179-30' (15' Blk, 15' Red) 2 Gauge AWG Welding Lead & Car Battery Cable Copper Wire BLACK + RED | MADE IN USA

$73 TEMCo INDUSTRIAL WC0179-30' (15' Blk, 15' Red) 2 Gauge AWG Welding Lead & Car Battery Cable Copper Wire Black + RED | Made in USA

https://www.amazon.com/dp/B00LIB7NF0/ref=cm_sw_r_cp_api_i_DyGPEbX3P2HWM

 

Sort of. You need at minimum a second battery, cable, a place to put it, and <something that connects the batteries>.

<something that connects the batteries> can be one of:

• isolator
• automatic charging relay
• dc-dc charger
• a fuse

Personally, I went with an automatic charging relay because the others all have drawbacks:

• isolator - you usually lose ~1V through the isolator when charging, so you never really get a good charge
• a fuse - because you really do want to separate your batteries - that's the whole point when you're in camp and want to be sure that you'll have power to start in the morning.
• dc-dc charger - because a 1st gen tacoma alternator easily puts out 14.6V and doesn't scale that down for fuel efficiency, so you don't need the extra charging boost of a dc-dc charger. PLUS, a dc-dc charger doesn't allow you to link the batteries for more winching power, etc.

Besides all that stuff, you probably also want to have:

• A fuse(able link) on any long (+) cable runs
• A fuse panel connected to the second battery for accessories
• A circuit breaker between the second battery and fuse panel.

(Note: these are all covered in the post I linked above)

A DC-DC charger is a good thing on a 2nd or 3rd gen, but unnecessary on a 1st gen, where the alternator has plenty of output (at all times).

That wire looks great. Personally though, when connecting two batteries, I'd use a 1-0 gauge or 2-0 gauge since you're running a lot of current when the batteries are linked (for winching, etc.)

 

Excellent points! Thanks for clarifying.

I put my stuff together so long ago I’ve forgotten what I did.
Yeah, I have solar and my solar controller is also a dc-dc charger. I think that’s what I might have been thinking.

Would you say linking batteries together to be good or bad or in between if the aux battery set up is a true deep cycle like say a pair of 6v golf cart batteries wired in series for 12 volts?
What I’m thinking is that from what I’ve read that kinda deep cycle doesn’t like to be drained quickly. But I’ve also read the FLA golf cart batteries can take a lot abuse. And they wouldn’t be linked for winching a lot either.

 

You know, I'm not sure in that situation... I've always seen setups where the two linked batteries (starting and aux) are either the same battery, or at least the same brand/type (i.e. both AGM if not the same size/capacity)

Really, if the plan isn't to use the two batteries (or perhaps more correctly, banks) linked together to provide power (jump starting yourself and winching are really the only two things I can see necessitating this), then a DC-DC charger (+solar) seems like a great solution.

I should also mention - I think a lot of folks look at automotive batteries today from only the traditional "big-ole-12V-bohemouth" perspective. LiIon is (IMO) getting good enough that for a lot of our camping uses (powering fridges, camp lights, charging devices, etc.) that they should be considered as well. Sure, you won't be using them to winch or linking with your starting bank, but 99% of folks don't need that anyway.

 

Yeah, I’m really looking forward to LiIon coming down in price. They’re better in so many ways. Like you said...for running stuff like a fridge etc they’re really nice.

I have a pair of 6 volt golf cart batteries in my camper with 115 usable ah (230 total). They’re 12O pounds!

115 usable ah if LiIon would weigh like 55 pounds!

The golf cart batteries were $275. In the long run LiIon would be cheaper because they’ll last so much longer. I’d also need a new charge controller.

But I just spent a bunch of money building my own camper on my truck and had to cut some corners. Otherwise LiIon would be the way to go.

 

@turbodb - This dual battery setup is really inspiring! I'm trying to wrap my head around doing something very faithful to this, but putting the house battery in the engine bay. Do you have any sort of wiring diagram you roughed out before starting this? Trying to wrap my head around all the wiring and it's a bit overwhelming!

 

This is what I have drawn out so far using Photoshop. Does this look correct?

Any help or pointers from anyone would be appreciated. I only have my grade 10 in electrical.

 

Looks good.

Sorry for the slow reply. Out on the trail right now.

 

Question! why do people run duel battery? To power the winch ? lights?

 

From my own personal research, yes. Winches can draw a lot of power as well as certain high power offroad lights.

I think the other main appeal is that you can run miscellaneous electronics for long periods without having to worry about draining your starter battery.


Case in point - every time I'm waiting for a ferry, there's always "that one guy" that's been blasting his car stereo with the engine off the entire time while waiting for the ferry to arrive.
When it's time to load onto the ferry - guess who doesn't start up and delays the entire lane behind him...