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Good Morning-
Last week my battery died (1998 S70 T5M, original battery). I ended up buying the Interstate battery (thanks to everyone who gave me input). Car starts fine now.
Here is my question, with regard to cold cranking amps. The Interstate dealer said my need 520 CCAs, sold me their battery with 590 CCA (of course this is better). Pep Boys said my car needed 520 CCA. Sears webpage says my car needs 520 CCA. Les Schwab Tire says my car needs 520 CCA.
The dealership parts department (Northwest Volvo) says my car (the T5) actually needs 600 CCA, and the normally aspirated engine only needs 520 CCA. I look at the old battery I pulled out (I didn't recycle yet), and lo and behold it claims 600 CCA.
Is 600 CCA what I need? Now, relatively, it doesn't get too cold around here, so maybe a lower CCA is justified, but what has everyone else bought for their T5 or 850 turbo? Seen any short life on a battery less than 600 CCA? Should I try to return the Interstate and buy the volvo battery ($75 versus $117)?
Joe
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Hi Joe,
CCA (Cold Cranking Amps) means that if you were to short out the battery you would draw (in your case) 590amps DC for a few second. In other words CCA means the maximum amount of current you will be able to draw form the battery over a short period of time (seconds). There is also another specification on your battery and that is amp/hours. This is the long-term current draw capability of the battery.
As an example:
If you have a battery that is specified for 40 amp/hr, you could draw 40 amps out of the battery for 1 hour. Then the battery will be dead and need a recharge.
What you purchased is a battery that will last at least 3+ years in your car. After that you will be living on borrowed time.
As a trained Electrical Engineer I recommend that on your next battery purchase throw the book out the door. Take a tape measure and measure the size of the battery holder (length, width and height). Also take note on the battery hold down mechanism. Then go out and buy the biggest battery you can find that will fit into your battery holder. I shoot for batteries that have 700CCA or higher rating. These batteries will last for 5+ years.
My 99XC has a battery with a rating of 600CCA and I could fine no amp/hr rating. There was a number of 115min but I am not sure what this means. 115amps minimum or 115 minutes???????
As a footnote: When a car is started the electrical system will draw “about” 70amps from the battery. 20amps are for the electrical systems (engine computer, transmission computer and sensors). The remaining 50 amps are used by the starter. The reason for the higher rating on the battery is the higher the CCA rating the better the battery. You could install a battery that is rated at 300CCA and the battery will work just fine. However the battery will last you about 1 to 2 years.
Good Luck,
Steven---
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Hi Steven-
oh no, an EE, really? As a mechanical engineer, I want nothing to do with anything electrical. its bad black magic as far as I'm concerned.
Anyways, for CCA, I was going by the description on the Johnson Controls web page: "CCA is critical for good cranking ability. It's the number of amps a battery can support for 30 seconds at a temperature of 0 degrees F until the battery voltage drops to unusable levels. A 12V battery with a rating of 600 CCA means the battery will provide 600 amps for 30 seconds at 0 degrees before the voltage falls to 7.20 V (six cells)."
Since the dealership said 520CCA for NA engine, 600CCA for the T5, and all the independant shops had only 520CCA in their specs, I was wondering why the T5 needed more power (and if I'd shortened my battery life by buying a 590CCA battery).
As far as the time printed on your battery, I'll bet thats RC (reserve capacity): "RC helps to power your vehicle's electrical system if the alternator fails. It indicates the battery's "staying power" -- how many minutes the battery can supply ample power without falling below the minimum voltage needed to run your vehicle." I also got that info from the Johnson Controls web page.
Thanks for the help. I would like at least another 5 yrs out of this battery.
Joe
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posted by
someone claiming to be Ray Niblett
on
Tue Jan 29 09:42 CST 2002 [ RELATED]
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Regarding battery life: Heat is also important. Where you live
could be the major factor. Live in Texas or Florida and it
won't last as long as one used in the San Francisco Bay Area
or New England.
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Hi Joe,
Yep I’m an EE. You know “Double the Voltage, Double the Flux, Double E, Double E, Double E, Sucks”. An old Collage expression the Mechanical Engineers use to say to us EE.
Anyway, The Quote you posted from Johnson Control is correct on the CCA. However Reverse Capacity make no sense to me. Back to my example of a rating of 40amp/hr; If you attach let’s say a radio to a battery that has a rating of 40amp/hr and this radio draws 10 amps from the battery, than the battery will last 4 hours before it is dead.
What you Quoted from Johnson Control makes no mention of the type of load that is on the battery. A light load will allow the battery to last longer than a heavy load.
Back to your question; Why does a normal aspirated engine have a smaller battery than a turbo engine? Well I would assume that it has to do with cost. Normal Aspirated engines are install by Volvo into cars that are sold as low-end models. You know cars that have no bells and whistles. No thrills. Hence Volvo wants to keep the cost down. Where as the high-pressure turbo engines are installed in the high-end models. Lot of bells and whistles. Therefore, it takes a battery with more current reserve to run those bells and whistles. Other than this I can see no other reason. The starter would be the same and engine compression would not make that much of a difference. If engine compression did make a difference than a normal aspirated engine has a higher compression, which would mean you need a battery with more capacity and not less.
I Hope this helps,
Good luck,
Steven---
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posted by
someone claiming to be Robert Chase
on
Thu Jan 31 06:58 CST 2002 [ RELATED]
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FYI
I have a non turbo S70 with every option (except for TRACS since mine is a manual). A lot of people who wanted 5 speeds went for the non turbo because 168hp and a 5 speed in some cases is faster than the 200hp Low Pressure Turbo with the Automatic. Driving Loaner S70 Low Pressure Automatic's has always been an act of patience for me driving the Non Turbo Automatics is an act of sainthood
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Hi Steve,
Thanks for the conversation. I believe you are correct. I called the dealer, and they did babble something about more accessories standard on the T5.
With respect to RC, from Johnson... "how many minutes the battery can supply *ample* power without falling below the minimum voltage needed to run
your vehicle." There is probably a spec somewhere that dictates what the requirements are for "ample" power, but already I feel I know too much about my battery.
Living in the Pacific Northwest, it gets neither too hot nor too cold, and I usually shut off my radio and blower fan and lights, etc, when I shut the car off. So I am thinking the 590CCA should be sufficient for the moderate temps I live in. Ask me again in a few years...
Thanks again
Joe
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Hi Joe,
One last foot note. Save your switches. You do not have to turn off all your accessories. When you turn the ignition switch to start the engine the ignition switch turns off all accessories in the car. In short when starting the car only the necessary electrical components get electrical power. All other non-essential electrical accessories are turn off until you release the ignition switch.
Good Luck,
Steven---
P.S. I live in San Jose CA where it never gets cold and the Sunshine from May to October. Oh I forgot to mow the lawn yesterday. I am out of here.
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Yes the accessories cut out during cranking, but all come back an instant later, against a battery that has just done its hardest work. Do you have an o'scope and camera? I would love to see a trace of that battery with and without accessories. There have been a lot of complaints about premature battery replacement here; I turn on my headlights, seat heater, radio etc. after the system stablizes (maybe 10 sec), this while oil gets to my turbo. It just seems like it would be gentler on the battery/electrical system. (Not to mention the CPU which has god knows what primitive current/voltage regulation/protection...)
BTW I would love to hear your EE retort to the college ME taunt you mentioned earlier :)
- Tom E
--
98 V70 GLT black 54k
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Hi Tom,
When you finish cranking the engine the Alternator takes over. So the battery is only used for starting the engine and operating the accessories when the engine is not running. Once the engine is running the alternator provides all of the necessary power to operate the car and recharge the battery for the next start.
One test I do to see if the alternator is working at peek proficiency is to start the car and remove the negative battery cable with all systems in the car running (beware of hydrogen gas). With the battery disconnected and the engine running the alternator should produce enough electrical current to operate the entire car. If not then you need a bigger alternator or a new alternator.
As for a ME chant my memory fails me. Where I went to school the EEs out number the MEs by 10 to 1. So it took a brave ME to shout a chant. :-(
Good Luck,
Steven---
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posted by
someone claiming to be HR
on
Mon Jan 28 15:36 CST 2002 [ RELATED]
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I'm not sure about the CCA's, but I would stay away from the volvo batteries. Though, I think that the batteries are exactly the same in both our s70na and v70t5. The techs I have talked to have not had good things to say about the volvo batteries. They tend to fail without any warning and at no consistent interval. On our s70, we warrantied 2 in a 6 month period and on my v70 I warrantied once. They all failed again within a few months and then got diehards for both. This on 2 cars with less than 45k. No problems since (and significantly cheaper).
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posted by
someone claiming to be Ray Niblett
on
Mon Jan 28 10:53 CST 2002 [ RELATED]
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I wonder if the dealer got it backwards? The normally aspirated
has a higher compression ratio so it should be harder to turn over.
In theory, the turbo engine turns over easier and would need less
cold-cranking power. Well, makes sense to me but is is just a theory.
I'd keep the Interstate. There were two sizes available when I got
mine and I went for the smaller size on my 98 T5M. Two winters
with no problems. (We don't see anything below 30 degrees, though.)
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