Honestly I think Optima batteries aren't really worth their weight and gold,
Yes their a very good battery as I've owned one, but for their price its a bit to much,
The retail from $360 - $480approx, for that price you can get 3-4 good quailty GSYUASA 480CCA batteries, say a battery lasts you 2years...thats 8years of gsyuasa batteries to one optima.
(Something the guys at battery world told me) might be worth considering.

COuple of ways you can have a volt meter

-I"ve just installed a volt meter on the battery Around $30
-Some Amps (I knwo alpine V12) have a volt meter reading so you know what voltage is going in the amps
- If you drive a ef/el nf/nl with trip computer theres a little trick you can do that shows you your volt reading on the dash
- or a capacitor

- Ash

I just did the same research and basically got the same prices and came to the same conclusion about preferentially using std type batteries.

I ended up getting a 900cca battery for $182, but it retails for $215.
The largest optima is 600cca and retails for $475.
So i've got 50% greater capacity, for 45% the price (comparing retails), and it should last longer due to the greater capacity being less affected by the loads.

Optima's are also less available, i would have had to drive 500kms return to get one, so you might have to factor that cost in as well.

The 600cca optima is 27kg and i reckon the one i got is around the same weight, but probably about 4" to 5" longer. It's loong.

So its ok to run GSYUASA batteries in the boot?


And thanks for all the great help guys, appreciate it

If you are using a std type lead acid battery you should use a battery box to contain the muck. Even if you use an optima type you still need to protect the terminals from being shorted by any loose conductive objects in the boot.

Many of the battery boxes i've seen are rather big boofy things that take up a lot more space. But in my situation the battery i chose was too long for even an extra long battery box. It has the terminals up one end which means they are somewhat tucked away at the back of the boot, and i'll cover them. It is a "maintenance free" type meaning there aren't any screw-off caps. The top is neat and its all black, so it looks fine, and is fine without a box except it does still ventilate in some way and might still expel some muck. The inside of it can still be accessed via a screw in charge indicator, so i am told i can still add water if i so need and desire. I think i will hold it down with a ratchet strap.

Repco quoted $19/m for 245A cable but i got some from "Nolans" Eden for $13/m. I asked for 5m of the red stuff and got about 30cm more and ended up needing just under 5m. This went from the starter motor, through a section of chassis rail, through the floorpan into the far left passenger compartment not far behind the ECU, under the edge of the carpet, under the rear seat and through into the front right of the boot where the battery is. The original red lead to the starter remains in place. I connected earths from the rear top shock tower to the battery.

At the front battery location i joined the red connectors and wrapped them in a fair amount of red tape, and joined the black connectors (and for convenience screwed them to the chassis).

It depends, im not sure if GSYUASA make Dry cells, IF you were to have a battery in the boot, you would want a dry cell (Caution: they still legally need to be vented) so you will need to have some sort of venting system...
Acid liquid batteries give off a toxin hence are not recommended for boot installs,
Either get a Dry cell, or stick with th ebattery in the engine bay (theres not a huge difference in having it boot or engine bay)..

(Sorry havn't replied for ages, forgot to check this post )

Cheers
- Ash