Thread: Replacement battery for a D4

Originally Posted by DiscoJeffster

Well I am wrong. Too much CCA can damage a starter motor, but we’re talking double the expected, so not an issue for whatever size you’ll fit into the standard tray

No, it make no difference how much bigger the battery is, the starter motor will only draw what it needs.

Having a battery with too little can be a problem, but you can have a battery with 10x the CCA needed and again, the starter motor will still only draw what it needs.

Originally Posted by drivesafe

No, it make no difference how much bigger the battery is, the starter motor will only draw what it needs.

Having a battery with too little can be a problem, but you can have a battery with 10x the CCA needed and again, the starter motor will still only draw what it needs.

From a friend

Not according to a starter manufacturer

I think we’re safe. Not many 12v batteries that fit our vehicles that’ll get that high

Originally Posted by Tombie

I think we’re safe. Not many 12v batteries that fit our vehicles that’ll get that high

Of course. If you put it into perspective then twice the CCA of recommended can damage a starter. This was news to me. In the real world you’re unlikely to ever see such a situation, but I’ll admit I was wrong.

In the real world, you would have to defy the Laws of Physics!

It is the starter motor that governs the amount of current it will draw, regardless of the battery size.

If you have a huge amount of CCA available the starter motor will be able to run at a slightly higher voltage, but even this would be irrelevant because of the short operating time and would actually be GOOD for the starter motor.

A perfect example is the fact that because the of way Traxide isolators work they will regularly double ( and in many cases even triple ) the CCA to the starter motor and yet with tens of thousands of Traxide isolators supplied over the last 30 years, I have never heard of a run of starter motors burning out.

Tombie use to have an additional 1500 CCA available when he started his motor.

So Tombie, how many starter motors have you have to replace?

None.

I have had to replace contacts only in the last 3 vehicles. The actually starter motors have always been ok

I think the manufacturers are just covering their bums. MT starter motors are usually fitted to larger engines (trucks).if you crank an engine starter for some time it will produce a lot of heat and discharge the battery somewhat. If you have a high CCA battery you can crank that starter a lot longer and potentially melt it internally. Under "normal" conditions , not an issue.

Originally Posted by drivesafe

In the real world, you would have to defy the Laws of Physics!

It is the starter motor that governs the amount of current it will draw, regardless of the battery size.

If you have a huge amount of CCA available the starter motor will be able to run at a slightly higher voltage, but even this would be irrelevant because of the short operating time and would actually be GOOD for the starter motor.

A perfect example is the fact that because the of way Traxide isolators work they will regularly double ( and in many cases even triple ) the CCA to the starter motor and yet with tens of thousands of Traxide isolators supplied over the last 30 years, I have never heard of a run of starter motors burning out.

Tombie use to have an additional 1500 CCA available when he started his motor.

So Tombie, how many starter motors have you have to replace?

You still miss the point. The question was binary and my answer was also binary but incorrect. That the likelihood or reality of actually damaging one are different is a moot point. The correct answer is yes, you can have too much CCA, HOWEVER in reality you’re unlikely to ever achieve too much capacity in a vehicle with restricted battery capacity, but caveat emptor.

The scenario where too much CCA damages a starter motor is likely only if the starter is used for long periods with excessive CCA - eg excessive cranking where the engine doesn’t start and is continuously cranked. Again, one in one million case and unlikely to occur in our vehicles, but doesn’t change the fact that at least one manufacturer states you can have too much CCA, at least for their brand starter.