Thread: Optima N70Z equivilant

I run whatever the biggest bluetop is as a replacement for the original battery. So far its been excellent.

Hey Slunnie,

Out of interest, why did you choose a blue top as opposed to a yellow top ?

I'm not sure how they are promoting the batteries now, but when I was buying the red tops chemistry was designed for a starter battery and the yellow top had deep cycle chemistry in it. This said, I tend to think that the yellow top was also popular as starters also which was was probably because there is so much surface area within the battery, but irrespective the yellow top was a deep cycle.

The blue top had an intermediate chemisty and was designed for both starting and deep cycling, which is typical of marine applications. I needed something to start, work a winch and operate a fridge. I've now got dual batteries, but the blue top was on the money for me. The blue top was also at the time (not sure about now) the only battery option in that size, the red and yellow tops were all too small to replace the main battery in a D2.

As a very handy bonus, the blue top also has accessories terminals which I do all of my wiring to.

If you look at the data sheets on the different batteries the blue top seems to come in as slunnie said.The yellow top , unless you opt for the commercial one only goes up to 55a/h with I think 700cca.
The blue top D27m although a larger size battery has 66a/h with 845cca. You can go bigger but im trying to get 2 batteries the same and can fit this model as the 2nd battery in the space I have.
The res top is definately a starting battery according to the spec sheet that I read.
Cheers Ean

Originally Posted by Ean Austral

Gday All,Is anyone using or tried these Optima D27M Blue top..was thinking of using 2 of these to replace the 2 oddball batteries that I have at present..Never seem to have much joy with different batteries and these seem to be about the size im after..
Cheers and Thanks Ean

Hi Ean

I use a D27M + D31M as a dual battery setup. I bought the D31M first for another reason and when I wanted a dual battery setup in my Puma defender I found that two D31M batteries wouldn't fit in the battery compartment. The main problem was the height and the D27M isn't as tall so will fit side by side with the taller D31M towards the front (deeper part of the compartment ) and the D27M towards the back (shallowrr part of the compartment). I have a heavy duty marine switch that I use to manually switch between the two batteries...ie both batteries are used as the starting battery. Whichever one is switched on runs everything in the car and the other sits as a fully charged backup. I switch over when I arrive at a trip destination or normally around town I switch over each Friday.

The D27M has 800CCA versus the 900CCA of the D31M but has had no problems starting the vehicle all through winter. The original Landrover battery that I removed is marked 800amps SAE, so I am assuming that means 800CCA. The Optimas seem to deep cycle no problem running an Engel, various chargers, lights and assorted accessories either DC or through a small inverter.

Both marine batteries are rated as dual startup/deep cycle types.

As I see it Optima batterys have three main advantages over the standard calcium lead acid battery that came with the D2.

1/. Extremely fast charge assuming your alternator can keep up supply.
2/. Extremely robust, no collapsed cells when driving on corrugated roads with these batterys.
3/. For a start battery has high CCA for small physical size.

On the down side.
1/. Very low capacity (amphours).
2/. Heavy for their size, they might fit but will the mounting hardware take the weight.
3/. Very expensive

For my money, if you don't need a fast charging extremly robust small start battery you're better off buying a good calcium lead acid battery.

If you've got an older car, like my RRC, one with a charging system that runs at 13.5 volts, then theres little point in getting anything but a conventional lead acid battery as it isn't capable of fully charging a modern battery.

Got nothing against Optimas, I reckon they're a great battery in the right place. I also reckon they're over rated, over used and over priced.

Deano.

Originally Posted by Ean Austral

If you look at the data sheets on the different batteries the blue top seems to come in as slunnie said.The yellow top , unless you opt for the commercial one only goes up to 55a/h with I think 700cca.
The blue top D27m although a larger size battery has 66a/h with 845cca. You can go bigger but im trying to get 2 batteries the same and can fit this model as the 2nd battery in the space I have.
The res top is definately a starting battery according to the spec sheet that I read.
Cheers Ean

Ean, here are some pics that I picked up a couple of years ago. The first 2 are in a V8 with Optimas, the last 2 in a TD5 with an Optima and something else. All have shifted the ECU and jack to suit.