Thread: Optima Red Too Heat Resistance?

Is this right? Can I swap my cranking and aux batteries over?

Yes you can.
I have done this.
It involves a new AWG OO starter cable, a new cable to the fuse box AWG4 , new earth wires to block and body ( what I did) and a new cable to the 2nd battery controller( or just reverse your controller). All new cables covered with convoluted stuff or the spiral stuff.
On the house battery I just connected to the rear with AWG 4 cable through a big fuse. Battery controller placed at RH rear of engine compartment near the brake booster.

My Optima blue top was replaced after 3.5 years with another blue top as I had some problems starting which turned out to be injector washers. LOL

The seller of the blue top in Brisbane told me not to expect the same life from a new one as they were now made in Mexico .Time will tell.
Regards Philip A

Originally Posted by PhilipA

The seller of the blue top in Brisbane told me not to expect the same life from a new one as they were now made in Mexico .Time will tell.
Regards Philip A

I keep hearing that, but Optima ceased US production in 2009. Many Optimas were produced in Mexico prior to that date. So, unless your previous Blue Top was at least 9 years old there should be no difference at all.

Originally Posted by PhilipA

On the house battery I just connected to the rear with AWG 4 cable through a big fuse.

What size fuse? AWG4/4B&S so 120amp?

Actually, I’ve run 3b&s from the dual to the towbar and then into the camper. Might stick with 3b&s which is rated to 150amp

But I’m not a sparky so I’m happy to take advice from others.

What size fuse? AWG4/4B&S so 120amp?

No I have a 60Amp fuse as the highest load I have is 50amps for the compressor and about 4 for the fridge. I have never blown it .The 4B&S is to minimize voltage drop. From my reading that is the correct way to avoid fires.ie rate the fuses on the expected maximum draw rather than the capacity of the wiring as long as the wiring is heavier than required.

I also have fuses rated for the load expected on each circuit at the back. I learned this one on Cape York when I was bogged and had to be winched up Cannibal ? Creek. The bumper bar went under and shorted a merit plug I had on it and blew the main fuse to the fridge and everything. BUT unbelievably the bloke in Seisia had a selection of maxi fuses.

I use a Jaycar MAXI fuse holder as used by the Doof Doof blokes , and now I have several spares.LOL
Regards Philip A

Originally Posted by John_D2

................. Is this right? Can I swap my cranking and aux batteries over?

Sounds like a pretty smart move to me. The Optima (red) D34 is relatively small physically so with the factory 'reset' switch etc. relocated a reasonable air gap/heat shield can be attained between the new start battery and the turbo/exhaust which means it's less prone to heat damage than a physically larger deep cycle auxiliary battery in the same location. As long as the 'new' battery to starter motor cable is properly dimensioned to take into account the increased length all should be good Sounds like a pretty smart use of space/resources to me.

The factory Delkor battery is bigger than N70 size so a decent capacity AGM deep cycle should fit in the same space. If you go nuts and relocate the jack (which needs to be done anyway) you have even more room to have an even bigger aux. battery.

Deano

Originally Posted by PhilipA

No I have a 60Amp fuse as the highest load I have is 50amps for the compressor and about 4 for the fridge. I have never blown it .The 4B&S is to minimize voltage drop. From my reading that is the correct way to avoid fires.ie rate the fuses on the expected maximum draw rather than the capacity of the wiring as long as the wiring is heavier than required.

I also have fuses rated for the load expected on each circuit at the back. I learned this one on Cape York when I was bogged and had to be winched up Cannibal ? Creek. The bumper bar went under and shorted a merit plug I had on it and blew the main fuse to the fridge and everything. BUT unbelievably the bloke in Seisia had a selection of maxi fuses.

I use a Jaycar MAXI fuse holder as used by the Doof Doof blokes , and now I have several spares.LOL
Regards Philip A

Cool. Thanks Phillip

Originally Posted by DeanoH

Sounds like a pretty smart move to me. The Optima (red) D34 is relatively small physically so with the factory 'reset' switch etc. relocated a reasonable air gap/heat shield can be attained between the new start battery and the turbo/exhaust which means it's less prone to heat damage than a physically larger deep cycle auxiliary battery in the same location. As long as the 'new' battery to starter motor cable is properly dimensioned to take into account the increased length all should be good Sounds like a pretty smart use of space/resources to me.

The factory Delkor battery is bigger than N70 size so a decent capacity AGM deep cycle should fit in the same space. If you go nuts and relocate the jack (which needs to be done anyway) you have even more room to have an even bigger aux. battery.

Deano

I hadn’t thought of moving the jack. I prob won’t because I think 130/150 amp should be plenty, but imagine the size of the battery you could fit!

So I was thinking of using some ?5mm aluminium as a heat shield along the 2 sides of the battery exposed to the engine. What has everyone else done?