2nd battery install question

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Super77

Super77

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I've got a new second battery sitting around. Not a deep cycle, just a regular 800CCA one. I'm wondering about how to make use of it. I've seen rigs with dual-battery setups, but it seems you have to desmog, no? I don't see any other way of making use of the second battery tray location without clearing out all that emissions clutter.

Second, wire in always-connected parallel, or put a switchover in between? I need 12V, and the truck is nearly stock. No high electrical load. I just want to put those extra amp-hours in the truck instead of in my garage.

Finally, can a stock output alternator handle dual-battery setups? I'd be charging both at the same rate. It's not like the batteries have a draw on the alternator, right?
 
The benefits of a 2nd battery is most useful when one goes flat and you have fully charged battery as a spare. I have a switch that has 1,2,0 on it. Once one both batteries are charged, I switch over to the battery I want to use. Every few months I switch to the other battery.
When I go overseas, I switch it to 0. You can also get switches with keyed locks on them. Its not a fool proof theft deterrent, but most thieves don't want to spend time working how to get around it.
Stock alternator will easily charge 2 batteries.
My last 75 series had solenoid switches that would allow one battery to start the engine. Once the alternator cut in ,it would open the other 2 batteries for charging. The 3rd deep cycle battery was for my 2 fridge's and lighting when I was camping.
 
I have a 60, you have a 62, so there are some differences as you know. Can't offer any advice on smog w/out looking at what you got. But you could stop by if you want.

Easiest is to use a VSR - voltage sensing relay. Once the voltage reaches a pre-determined level, the relay opens and the second battery is now charged along with the primary. Stock alternator is fine for this.

Wired in the most simple way, you will always have a second charged battery on board. Jumper cables are then used if/when the primary battery is dead.

Lots of ways to make this more complex. Lots. PM me if you want to talk more.
 
It works, I have one in my FJ62 right now.

Do yourself a favor and buy one of these:
Stainless Steel Battery Trays for TOYOTA LANDCRUISER

Install battery and wiring. I agree with @lovetoski that a VSR (also called ACR) would be a great way to tie it together when chargine and separate the batteries when not.
 
I have a 2FE in my 85 FJ60 and it still has the smog equip. on it. No problem with setting up a 2nd battery. Used the isolator from DFNA.com a 1/2 banana install. Kit comes complete and is cheap! Stainless battery trays like CRUISERDREW recommends best in the market, in my opinion. TRY TRUE SMART BATTERY ISOLATOR.COM
 
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If you decide to run parallel batteries, there is a right way and a wrong way to wire them. You must spread the leads across the batteries otherwise you will kill both. You are trying to make one large battery out of two batteries. It's a long explanation, but suffice it to say that doing things the easy way by adding a second battery and running two cables to your factory battery will cause both to overheat and die in under a year.

Allow me to exercise my MS Paint skills to show how to properly wire this:

battery.webp
 
JMJA said:
I have a 2FE in my 85 FJ60 and it still has the smog equip. on it. No problem with setting up a 2nd battery. Used the isolator from DFNA.com a 1/2 banana install. Kit comes complete and is cheap! Stainless battery trays like CRUISERDREW recommends best in the market, in my opinion.
Click to expand...

DFNA.com does not work
 
You can safely take out the "silencer" canister, which is part of the smog system, but totally unnecessary.
That should make room for your 2nd battery. I agree with the stainless trays for the batteries. While I was
doing this all, I ended up getting a second tray for my original starter battery which was on a pathetic
rotted out tray. You're standard alternator should work fine, or you can upgrade.

After you take out the silencer canister, you might have to relocate or find a creative solution for your radiator fill/overflow reservoir.

I used a Blue Sea switch & solenoid system, and ran red and green welding cable to install my second battery. I can post more details or pics when I get home, if you need. I think I can find part numbers maybe.

Good luck.
 
I have an 88 FJ62 and just completed a dual battery system. Feel free to pm me and I can facetime you and show you the install step at a time.

My parts list:
Second Battery (I went with a deep cycle)
Second stock battery tray, minor mods to support bracket fits well.

Blue Sea Systems ACR, model # 7622

Blue Sea Systems Circuit Breaker (two of these, 1 between each battery and ACR), some people use fuses instead which is fine too.
Two Gauge wiring running everywhere

I mounted the ACR in a waterproof box and one of the circuit breakers in a waterproof box off amazon. Then used waterproof plastic couplings to run the 2 ga wire through. The box mounts on the passenger side behind the air box near the firewall.


Super helpful tool: Harbor freight hydraulic terminal crimper (~$40 with weekly coupons)

Side Note:
Winch is connected separately to both batteries via a AC Delco manual battery switch rated to 360A continuous. (Warn M12000 pulls 440A max so use snatch block during hard pulls). 2 ga wire from winch to closest battery, long run uses 0/1 welding cable to reduce amp pull, resistance, and heat.
 
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