Battery strength, does "size matter"?

jbripps · jbripps's Garage

Hi,

Haven't driven the car in a about 7 or 8 weeks, and I got lazy and didn't start it up as often as I should have.

Anyhow, seems like the battery was so dead, that I could not jump start it, even after waiting for 1/2 hour with the cars wired up. Car was not pushable back into my garage, as I tried to pop the clutch to start, but to no avail.

I ended up running to costco to grab a battery in order to get it started and back into my garage before all of the snow came down, yes, I 'm on the east coast. My main issue is this......I bought a battery that is a regular size battery, while the "stock" battery I usually use is the Interstate MTP-93, which is much larger. This replacement has around the same coldcrank power (850). Car started right up and purred like a kitten. Question, am I OK to run on this battery? Is this going to damage any component of the car? I always wondered why there are so many sizes of a battery available. Any input is greatly appreciated.

Regards,

no substitute · 02-20-2005, 08:04 PM

I haven't used a stock battery in years. I buy one that fits the battery box I use. The best one I've ever had (power and longevity) was the Champion with 1050 CA. Cold Cranking Amps was probably a couple hundred less. The Optima Reds I've tried were no better or worse than the garden variety no maintenance batteries such as the Champion. I just bought a Champion that looks like a black Optima. I believe it's a 975 CA, and about 775 CCA. They've all worked just fine, and last about the same.

no substitute · 02-20-2005, 08:08 PM

BTW, some guys are using a very light weight racing battery and placing it in the smugglers box. Pricey, if I recall correctly, but it's hard to argue against considerably less weight (nearer the middle), and moving considerable weight away from the LF corner of the vehicle.

gerard vaglio · 02-20-2005, 10:23 PM

I just did this a few weeks ago, works great but then I live in sunny California.

The battery costs about $95 but the fancy shmancy battery box was about $160. You don't actually need this fancy mounting thingy, I've seen posts where people simply buy aluminum rod at the hardware store and mount it to the firewall , it only weighs
15lbs.

crashmy911 · 02-21-2005, 08:25 AM

that little battery looks like something for starting model airplanes! 13lbs is awsome though the battery I have in my trunk most weigh 40lbs

SLO-BOB · 02-21-2005, 09:09 AM

I had a Hawker in my 2002-they make the Odyssey batteries. The Hawker is identical except it's black and usually costs about $30 less. Very small and light. Being a sla battery, they don't like heat so be careful in California. Fantastic batteries.

To answer the question-no. It doesn't matter. The size is made to match the stock battery for mounting purposes. Same with terminal location. If it fits and doesn't move around-you're good to go.

On Optimas-very heavy and huge. I have one in a work van. That's about it.

masraum · 02-21-2005, 09:40 AM

Size doesn't matter, but the CCA's/CA's do. I used to sell auto parts, and used to have people buy batteries that had fewer CCA's than their car called for as the minimum. They'd be back complaining that the battery didn't last and we'd determine that they had bought a battery that was too weak.

Most likely your battery was just very, very dead. With a charger on that battery it would likely have eventually worked, or even with leaving the other car attached for another 30-60 minutes.

randywebb · 02-21-2005, 10:48 AM

I will disagree (somewhat). Unless different materials than the common lead-acid are used - or different designs (Odyssey spiral wrap), the size is highly correlated with the capacity.

You need to select a battery based on capacity (CCA is best) for the intended use. That will determine - to a large extent - the wt. and size, since they are all lead-acid based. NiMH, Zn-air and etc. are very rarely used in vehicles, esp. non-electric drive vehicles.

If you don't care whether or not your car starts or it is used for races, then you need less of a safety factor. I do care whether my car starts, as I am getting a little old to hike out of some of the places I park it to reach a well traveled road...

Someday we will have small, light wt. fuel cells to start our IC engines...

SLO-BOB · 02-21-2005, 12:18 PM

Lets take a battery requirement. We seem to all agree that cca is a good measure. Now take 2 cars that have the same requirement-say 650 cca. Despite the fact that they need the same cca, the batterys' physical sizes will, most likely, be different from one another. Try going to get a battery based solely on cca. It is a pita because the tech wants to sell you the right configuration. Are the posts on the top-side-are they posts at all or threaded bosses? Is the battery short and wide or is it tall and narrow? Is the negative on the left or right-front or back?

That said, you need to get the appropriate cca or above (I'm assuming the original poster did) and if you can make the battery fit securely, you'll be just as fine as if you bought the battery designed for your car.

In addition-cca doesn't tell the whole story when using sla's. For example-the Odyssey pictured above has around 200 cca if memory serves. But, it will work just fine under most circumstances. But that's another post.

911pcars · 02-21-2005, 01:05 PM

If you're limited by the installation area, then you do the best you can with what's available. That said, size does determine the CCAs. This is not saying all large batteries are equivalent.

I'll challenge anyone to find a smallish battery, like the Hawk or Odyssey (@ 220 CCA) that can output more than 700 CCAs at a cost of less than $200-$250.

If the Odyssey works in your application, that's fine. However, in cold climates, it may not because chemical activity "slows down". That's where the extra CCAs will be able to crank the engine.

Sherwood
http://members.rennlist.org/911pcars

SLO-BOB · 02-21-2005, 01:49 PM

Quote:

Originally posted by 911pcars

If the Odyssey works in your application, that's fine. However, in cold climates, it may not because chemical activity "slows down". That's where the extra CCAs will be able to crank the engine.

Sherwood
http://members.rennlist.org/911pcars

I live in Wisconsin. I never had a problem with the Hawker. Like I said, cca is different for sla's. Also, it's actually hot weather that affects sla's adversely.

stormcrow · stormcrow's Garage

I have been told although I haven't tried it that you can take flashlight batteries place them end to end to (8 = 12v) and you will be able to crank your engine with them.

So, is it the volts/cca or capacity that matters?

Steve

"A Porsche does more then just go fast in a straight line"

911pcars · 02-21-2005, 03:07 PM

"I live in Wisconsin. I never had a problem with the Hawker."

Sebring,
Let's see, it's about 20-30ºF in Wisconsin right now? Do you park your car outside or is it inside? If the Hawker does the job under these circumstances, that's great.

That said, extremes in temperature are NG for a battery. In normal service, a cold battery will not have the same cranking power as at warmer temperatures, hence the CCA rating (COLD cranking amps). If this test were performed at a higher temperature, then you have a rating called CA (cranking amp rating). The battery will have a higher rating.

Try cranking your starter motor with 8 D=type batteries in series. I can pretty much assure you it will not crank. If it's just voltage, connect 8 AA batteries (12 volts) and tell us what happens. You need amp capacity (flow) not just voltage (push).

Sherwood

SLO-BOB · 03:49 PM

Quote:

Originally posted by 911pcars
"I live in Wisconsin. I never had a problem with the Hawker."

Sebring,
Let's see, it's about 20-30ºF in Wisconsin right now? Do you park your car outside or is it inside? If the Hawker does the job under these circumstances, that's great.

That said, extremes in temperature are NG for a battery. In normal service, a cold battery will not have the same cranking power as at warmer temperatures, hence the CCA rating (COLD cranking amps). If this test were performed at a higher temperature, then you have a rating called CA (cranking amp rating). The battery will have a higher rating.

Try cranking your starter motor with 8 D=type batteries in series. I can pretty much assure you it will not crank. If it's just voltage, connect 8 AA batteries (12 volts) and tell us what happens. You need amp capacity (flow) not just voltage (push).

Sherwood

Actually I'm an electrical contractor so thanks anyways for the lesson on power.

Here's a link that explains it a little better if you're interested.

2002 faq

The info that he posts mirrors that on a very informative website dedicated to sls batteries.

Yes-my Hawker worked under these circumstances. What more can I say.

edit-here is the link to answer all your questions-

sla batteries

911pcars · 02-21-2005, 06:52 PM

Sebring,
I meant to direct the single cell battery response to Steve (Stormcrow). Sorry if that particular response was directed to you.

The first site describes a bimmer owner who installed two Odyssey PC680 batteries.

"I bought a pair of Hawker Odyssey PC680s ......"

Not sure of your point other than two create twice the cranking capacity over a single battery.

Two Odyssey PC680s @ 15 lbs. each total 30 lbs and their combined CCA rating is 560 (and 2 times $86). As I said, if the battery you have works for you, that's fine. However, I don't see anything superior here of two PC680s over other options. For example, a single Optima Red Top @ 33 lbs and 650 CCAs [720 labeled on mine] and $119 @ Costco seems like a better deal, albeit 3 lbs heavier than two Odysseys. However, two batteries, as we know with early 911s, allows the weight to be divided and placed more efficiently.

The second link seems to want to juggle their battery specs so they look better in comparison to others. Be that as it may, here's a battery chart from that site. You can see the relationship between size and battery capacity.

Regards,
Sherwood

no substitute · 02-21-2005, 08:53 PM

jb, if it hasn't yet been stated succinctly enough, match the cranking amps to factory recommendations or whatever your old battery rating is, and you should be just fine.