Need Advice on Dual battery kit

[Timsar]

Hi
I would like to add a second battery to my 74 K5, mainly to have enough juice to crank the engine and run auxiliary accessories:

1- Aftermarket stereo, amplifies
2- heated seats- 2x front, 2x back

Since I still have the original wiring and fuse box, I was thinking about adding a second modern relay/fuse box for the above accessories.

Any recommendations, advice, do's and dont's?

What brand/model if dual battery kit?

Relay box?

Thanks in advance for your help.

 

[Wes Harden]

you will want to update your alternator, to 100+ amps. The battery wire to the alt up size to 8 or 6 ga. Look for an ACR (automatic closing relay) to separate the batteries when engine is off, and will close when main battery gets to a set voltage normally around 13.2-13.6.

As for accessory fuse/relay box there are plenty out there. Figure out how many circuits and relays you'll need and get one big enough, maybe a circuit or two bigger.

 

[Timsar]

you will want to update your alternator, to 100+ amps. The battery wire to the alt up size to 8 or 6 ga. Look for an ACR (automatic closing relay) to separate the batteries when engine is off, and will close when main battery is get to a set voltage normally around 13.2-13.6.

As for accessory fuse/relay box there are plenty out there. Figure out how circuits and relays you'll need and get one big enough, maybe a circuit or two bigger.

So, if i have 4 heated seats, do i plan for 4 relays or pair them into two, one for front, one for the back?

 

[Wes Harden]

Me i would run 1 relay ea,with each having it's own fuse.
What is the amp draw of heaters ?

 

[Blue85]

For the applications you're talking about, a 2nd battery isn't necessarily mandatory. Assuming the stereo and seat heaters will only used while the engine is running, all you need is a bigger alternator. If you want to play tunes at the beach with engine off, then an aux battery makes sense. If it's just hard to crank you may just need a better/bigger battery or improvements to the wiring and/or external solenoid mod. There are many discussions here about mini-starters, the GMT400 starter, and fixing the problem with the GM solenoid wiring that solve all the heat-soak and slow cranking problems.

 

[Chris Ziemer]

This is my set up on the 82. The battery isolator has been absolutely terrific. Very easy to install and allows me to run my auxiliary battery down as far as I need without any adverse effects. If for some reason, the main battery dies, I can push the button on the unit and it joins both batteries. Very nice set up for me.
So I have a bunch of in-line fused stuff ran right to my auxiliary battery as well as an auxiliary fuse box.

 

[Chris Ziemer]

And if you’re having starter issues, I installed a quality mini starter years ago, and it has worked flawlessly, knock on wood. But makes starting much quicker.

 

[Blue85]

Info on different starters in here and how to do the remote solenoid: https://ck5.com/forums/threads/tell-me-about-mini-starters.346246/

 

[AZ79K5Project]

This is my set up on the 82. The battery isolator has been absolutely terrific. Very easy to install and allows me to run my auxiliary battery down as far as I need without any adverse effects. If for some reason, the main battery dies, I can push the button on the unit and it joins both batteries. Very nice set up for me.
So I have a bunch of in-line fused stuff ran right to my auxiliary battery as well as an auxiliary fuse box.

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I’m running the same set-up. I added a second battery. I have my winch and air pump connected to that battery.

For me, it’s a peace of mind knowing that if I actually use my winch or air compressor, I don’t have to run the engine or worry about the starting battery. If I have an issue, I have a built in jump battery too.