dual battery conversion

[Daveo91Burb]

So my '91 Burb does not have dual batteries but the '90 parts burb I had for awhile did. Both are 350 TBI. I took everything along those lines from the '90 before I got rid of it including all wiring, the tray, even the batt itself. Is it as simple as installing the tray on the drivers side and then wiring the positive to the terminal block on the firewall and then grounding the negative? I will want to use an isolater so the two batts don't have to be exactly equal and one will not drain the other. Where does that go? Any other suggestions?

 

[bucket]

I have two trucks with dual batteries. Both of them have POS to the POS on the other battery, and GND to the engine/frame. I've never had any drain issues at all, it's simple and it works. Great starting power in all temps and you basically can drain the power twice as much as a single batt setup and still start the truck.

 

[Daveo91Burb]

Cool, thanks! So you think it's even ok if the two batts are different brands/ages? I think they are the same size, but definitely different brands. If I have to start fresh with two new batteries this little upgrade would get a mite bit more expensive.

 

[ScottyB]

Match the batteries or don't do it. Your batteries will find balance between the two and it won't go up to the higher battery.

 

[bucket]

One of mine has matched batteries, while the other has a couple random batteries installed by the PO. The truck had no trouble cranking on the several -15* mornings we had. I'm sure matched is best though.

 

[NOPHO84K30]

Ive got two red tops with a 100 amp isolater i found at a junk yard.
It works as it should ive ran the radio for hrs and fires right up.

 

[circuitguy]

When installing two battery's in parallel "pos to pos" without an isolator make sure to use two new battery's of the same type, brand, ect. Otherwise the weaker battery will continuously draw from the stronger one, dont what that to happen....

 

[350runner]

this^^^^ is very true. no way to get around that at all.

Sent from the dust in front of you!

 

[MadOgre]

Andy and Scott are both right.

Pos to pos and both grounded to engine with passenger side to starter. And non matching batteries will shorten the life of batteries.

There is a solenoid on the drivers side fender for dual batteries which I cant recall at this moment how it is wired but all dual battery setups have one.

 

[DoubleDingo]

It would be nice to have dual batteries, especially in areas with bad climates.

 

[Daveo91Burb]

Andy and Scott are both right.

Pos to pos and both grounded to engine with passenger side to starter. And non matching batteries will shorten the life of batteries.

There is a solenoid on the drivers side fender for dual batteries which I cant recall at this moment how it is wired but all dual battery setups have one.

Yep, I have the solenoid you refer to. I don't remember exactly how it is wired but its harness is intact enough I think it will be obvious when I put it together. So what about the isolators that are available on the market? Would they help with the unmatched batteries?

 

[Moonsaber]

Ok, not to sound stupid. But here goes anyway, wouldn't two batteries give you a 24 volt system? Or is that when you run them POS to NEG, in series?

Never seen them linked up Positive to Positive before.

 

[350runner]

correct two 12v batts will provide 24v When wired in series positive to positive is more common in high amp draw situations.

Sent from the dust in front of you!

 

[Moonsaber]

correct two 12v batts will provide 24v When wired in series positive to positive is more common in high amp draw situations.

Sent from the dust in front of you!

Thanks @350runner!
I guess I have not spent a lot of time in colder climates outside the military.

I don't see that as a likely thing to do to my current square.

 

[350runner]

good deal! it's not really necessary for stock low amp draw situations.



Sent from the dust in front of you!