Recommend me a battery

[FLI20Y]

Originally Posted by blwnlj

MMmm well first ya need to check the charging voltage at idle and at about 2000rpm with a WELL charged battery,if all is ok the voltmeter should be around 14 volts with all accessories off,then you need to turn on all the gear,pumps fans what ever you have.Then same deal,the voltage hopefully will not drop below about 13ish volts at idle and should run back up closer to 14v at around 2000rpm held steady.If the voltage at the battery when running is heading towards 12.5 or lower the alt/wiring has most likely got issues as this needs to be better.Below 12 shes not charging at all.
Also check the belt is nice and tight and the alternator pulley is not red hot after a bit of a run.
Just another thought I see you have got a good size Batt lead on the positive side,whats on the neg side.Make sure if the earth is bolted in the boot somewhere, you have another earth loop somewhere for the body to engine block as the engine is rubber mounted and this needs to be bypassed.550+ cranking amp battery be fine in a standard case size or a N70ZZ or the larger capacity N70EX in a large case size if room.
If you do the charging tests let me know what you end up with and nut it out from there.

Cheers mate, I will do all of this on the weekend and let you know. The earth cable is massive (around 13m OD), and there is also another loop from body to intake manifold in the engine bay. Cheers for the advice

[fcv85l]

also take a meter reading at the starter during hot start to identify power or earth issue,also check charge rate at rear of alt,it should be close to the charge rate at the battery about .3v drop max under load

[FLI20Y]

Just a follow up on this topic, I borrowed a used Bosch Gold (CCA480) battery from a mate and it fixed the issue, turned everything on and it started first go, got the car hot and started it fine, so i'm guessing the old battery has been fried. I will still run the tests as one guy replied, it could be temporary as the CCA is higher, but i'm happy for now!

[DR327VK]

Becareful with using welding cable some are not design for cars stuff!

And if you thro your car around batterys don't like this!

[V8ESKY]

Originally Posted by DR327VK

Becareful with using welding cable some are not design for cars stuff!

Its not the cable thats the issue, its the insulation. Welding cable is usually good to use as its not prone to voltage drop when hot due to the lower impurities in the copper.

And if you thro your car around batterys don't like this!

Yep, on that basis you should be using a sealed battery, something like the Odyssey.
There have been quite a few major issues with Optima batteries lately, they have moved manufacturing from the USA to mexico a couple of years ago and quality has gone to shyt, with so many complaints its not funny. google it and you'll quickly find many forums are full of complaints as well.

As for the problem in the first post, the battery may not nessecarily be the issue, my guess is that the ECU may have a crook earth, they should keep running at around 8 volts so if its dropping out at 12 then theres a problem with it somewhere and from experience earthing is one of the most common on non-factory fitments.
Also, fans, radio etc should be wired so that all non-essential (or accessory) circuits are disconnected when the ign switch is turned to the start position. Car manufacturers do it for a reason, and thats to reduce the load on the battery to allow maximum starting/cranking capacity. It sounds like yours isnt doing that at all and the fans are remaining on while cranking the engine.
Also, if your starter is wearing out it may also have issues when hot. A tired battery will highlight the problem even more so, have it checked as well and yes I would also recommend replacing the battery as youve already discovered.

[kustom67]

Originally Posted by FLI20Y

Just a follow up on this topic, I borrowed a used Bosch Gold (CCA480) battery from a mate and it fixed the issue, turned everything on and it started first go, got the car hot and started it fine, so i'm guessing the old battery has been fried. I will still run the tests as one guy replied, it could be temporary as the CCA is higher, but i'm happy for now!

thats it mate he higher cca rating the more stronger the battery and less chance of power surge ,drainage ,and longer battery life