Starter motor power consumption

[mohammad]

Sometimes people on this form and the inter webs claim that a higher CCA battery makes your car start faster. Today i noticed the Factory service manual says that the starter uses 0.95kw at 12V. that works out to only 79.16 Amps.

My questions are as follows:

1. has anyone ever measured starter motor power consumption?

2. Does this mean that installing a battery with higher than 79 CCA will have no noticeable benefit?

3. what are peoples experiences with installing newer/higher CCA batteries?



Im curious because a lot of high capacity battery chemistries like LiFePo4 only allow for 200-300A peak discharge and i'm unsure if this is enough to reliably start the vehicle.

This post is for discussion purposes, i'm not currently capable of doing an alternator delete as i lack a power outlet to charge the battery with.

[Dirk Diggler]

I switched my OEM battery for a cheap AutoZone 35V battery that had higher numbers. I didn't notice any difference really.

[Daox]

1)
I have crudely measured power consumption on a 1997 Toyota Paseo (1.5L 4 cylinder). Starter power consumption is not anywhere near linear. It is a huge initial draw with a very quick drop off in power. I think the highest initial I saw was 300A but it quickly dropped to around 80A. This process took about 1 second if I remember correctly.


2)
The short answer I think is no, not really. It will start faster, but how much faster can it get? Starting takes about 2 seconds? I doubt it'll really get that much faster.

The reason that a larger battery will improve start up speed is due to voltage sag. As you increase the amperage load on a battery, the voltage sags farther. If you increase the capacity of the battery, the voltage does not sag as much. For example, lets say your stock Mirage battery sags down to 11V during starting. Now lets assume you use a gigantic battery and that voltage doesn't sag at all. It just stays at 12.7V. That is roughly 15% higher voltage. If that starts your car 15% faster (which is a big assumption). You've saved .3 seconds. Is that noticable?

3)
I personally haven't notice much difference. If my battery needs replacing, I'd check into a larger battery. I've looked into lifepo4, but the cost and the different charging voltage just doesn't seem to be a good fit.

[Mark]

Sometimes people on this form and the inter webs claim that a higher CCA battery makes your car start faster. Today i noticed the Factory service manual says that the starter uses 0.95kw at 12V. that works out to only 79.16 Amps.

My questions are as follows:

1. has anyone ever measured starter motor power consumption?

2. Does this mean that installing a battery with higher than 79 CCA will have no noticeable benefit?

3. what are peoples experiences with installing newer/higher CCA batteries?



Im curious because a lot of high capacity battery chemistries like LiFePo4 only allow for 200-300A peak discharge and i'm unsure if this is enough to reliably start the vehicle.

This post is for discussion purposes, i'm not currently capable of doing an alternator delete as i lack a power outlet to charge the battery with.

Since the factory battery is only 356 CCA, most anything after market is going to have more. A car battery for a cheap Mirage is not something I am going to over think in life. It's probably the easiest car engine to turn over (versus any other vehicle I have owned).

Although the factory battery is only 356 CCA, I am impressed by its performance so far. My car was built in January of 2017, and the factory battery still seems fine.

[mohammad]

Since the factory battery is only 356 CCA, most anything after market is going to have more. .

You seem to have completely missed the question mark, I was asking what people thought about the idea of replacing it with a lower current battery, 200-300 amps as mentioned in the question. The purpose for this would be to have a much higher capacity incase someone wanted to do an alternator delete.

[Mark]

You seem to have completely missed the question mark, I was asking what people thought about the idea of replacing it with a lower current battery, 200-300 amps as mentioned in the question. The purpose for this would be to have a much higher capacity incase someone wanted to do an alternator delete.

I thought you asked three different questions, but I'm glad the others answered correctly at least.

[allrock]

i think higher CCA helps, i have a larger battery installed on mine i just forgot how much is the cca but i think its 3SMF I dnt know if you are familiar with that sizing standard original batt is 1smf, but when i measure my batt health it will fail because the battery cant reach its original CCA anymore but still the car is not getting any battery issues because it may be failed to produce its original CCA but still the CCA it produced is still higher than the requirement of the car to start.

[CROSSBOLT]

This is a voltage plot of the start on a 300 cc scooter. The left prple line points to the first compression stroke, minimum volts, max current. Right after that is a successive compression stroke and then engine start/run, max volts current flowing into battery.
That first dip in volts is not as crucial as the second compression stroke because the second is when there SHOULD be enough voltage so the ECU will produce a spark and start the engine. On this model and brand of system, anything less than 9.5 volts the ECU will not make a spark. I think this is where the CCA rating may be of some value.

[Mark]

i think higher CCA helps, i have a larger battery installed on mine i just forgot how much is the cca but i think its 3SMF I dnt know if you are familiar with that sizing standard original batt is 1smf, but when i measure my batt health it will fail because the battery cant reach its original CCA anymore but still the car is not getting any battery issues because it may be failed to produce its original CCA but still the CCA it produced is still higher than the requirement of the car to start.

Unless things are different there, the size of the battery doesn't dictate the CCA of the battery. The battery group number dictates the physical size of the battery that will fit in your vehicle.

A local Walmart will typically carry 3 group size 35 batteries (recommended replacement size for a Mirage).
Everstart Value = 490 CCA/1-year free replacement warranty
Everstart Plus = 525 CCA/2-year free replacement warranty
Everstart Maxx = 640 CCA/3-year free replacement warranty

Likewise, places like AutoZone will do the same.

If all three batteries lose some CCA capacity over time, a higher CCA battery may do the job longer (justifying a longer warranty period).

[allrock]

Unless things are different there, the size of the battery doesn't dictate the CCA of the battery. The battery group number dictates the physical size of the battery that will fit in your vehicle.

A local Walmart will typically carry 3 group size 35 batteries (recommended replacement size for a Mirage).
Everstart Value = 490 CCA/1-year free replacement warranty
Everstart Plus = 525 CCA/2-year free replacement warranty
Everstart Maxx = 640 CCA/3-year free replacement warranty

Likewise, places like AutoZone will do the same.

If all three batteries lose some CCA capacity over time, a higher CCA battery may do the job longer (justifying a longer warranty period).

yah but my battery is original hitachi came from a diesel SUV and it wont fit on my plastic battery box im just not sure but i think its 565 CCA while the original is only 320CCA our 2013-2016 model here have the original hitachi battery the same as yours while the beginning of the locally manufactured unit is 2017-present have a locally made battery but the 2017 model has a 320CCA battery while the 2018-present only have 240CCA, they made the battery smaller from size 55D23 to 34B20. the new battery became literally smaller than the old models and has a lower CCA rating but i think you are right CCA is not the basis of physical size but capacity, so to answer the question no.2 higher CCA have a noticeable benefit yes not on the performance but on longevity.