viscosity vs battery cca

[JonS]

I was going to use a synthetic this winter here in Minnesota mainly to get better cranking @-20f or so. The last winters i could crank very slowly at -20f with a 650cca battery and Havoline 5w-30. Well, my battery died and i bought a 950cca battery. This should be a stronger battery at -20f than my old 650cca - right? So i should be ok with Havolione 5w-30 and not have to go with synthetic - right?
Any comments or thoughts?

 

[MolaKule]

The larger battery should be sufficient if you're using 5W30, which has a BPT of better than -33 F.

With that battery, you could probably use a 10W30 as well.

I have always upgraded and uprated my batteries on all vehicles since I felt they came from the factory with marginal batteries anyway.

I use at leat a 900 CCA on all my V-8's and a 725-800 on all my 4-cylinders. Heck, I even use a 625 Amp battery for my 16-25 HP woodsplitters!

Is this engine a 4-cyl, 6, or eight banger?

 

[JonS]

This is a 1995 Jeep 4.0 6 cylinder with 101K miles.

 

[VaderSS]

You lose about 15% for each 10F drop, so at -20 you 950CCA battery will be producing about 650CA and your 650 was producing about 450. The extra 200 amps should help considerably.

 

[Patman]

It's funny this topic should come up, as I'm about to replace my battery with something that has more juice, probably around 900cca or so. With the upgraded sound system I'm putting in, I just want to be sure I have enough reserve to keep the lights from dimming when the stereo is turned up. I believe the battery I have now is only about 600cca.

 

[JonS]

patman
You said you are going to use 10w-30 in the winter. Getting a large Cca battery would help your cranking if it gets cold. I chose to spend the money on a 950cca battery rather than the extra $$ for synthetic. I got a Exide Nascar battery at Checker auto for $99.99. Ouch!

 

[SteveD2]

I'd prefer the lighter vis oil for better flow and lubrication to the engine parts before they get fully warmed up...and in a Minnesota winter they may never get fully warmed on a short trip.

The 5W-30 will give excellent service. If you plan on keeping your car a long time, get synthetic 0W-30. Just because you can crank it and get it started doesn't mean that engine is ready for much of a load.

Ken

 

[jason07-1zzfe]

I had a Pep Boys brand 690CCA battery cranking over a 2.5L straight six running M1 15w50 all winter long without a hint of struggle.

[ August 15, 2002, 02:21 PM: Message edited by: Jason Troxell ]

 

[Patman]

Ken makes a good point, although I still prefer the 10w30!

Get a good 10w30 synthetic or blend that flows well at low temps, AND get the better battery, and you'll be sure it'll start up perfectly.

Even with my existing battery I wasn't worried about cold starting with the 10w30, but having the new one in there gives that added margin of safety.

 

[TooSlick]

Jon,

Even with the battery, I'd still run Mobil 1, 0w-30 in subzero temps ....You will get better wear protection on startup and significantly better fuel efficiency, particularly on short trips. In addition, you won't be draining the battery with excessive cranking. Synthetic ATF in the transmission and rear axle would also be an excellent idea at those temps. The mobil 1, 75w-90 gear lube should be available locally ....

TooSlick

 

[Patman]

When a battery is a few years old, how much cca does it lose? I looked at my existing
battery and it's 650cca. But the only battery I have found so far that fits is just a tiny bit more
powerful, at 700cca. But I'm just wondering, if my existing battery is 3 or 4 years old (which
it appears to be) would it actually be more like 500cca now perhaps? Walmart used to sell
a 900-1000cca battery a few years ago, but no longer does.

 

[pepper32]

Myself I would also be concerned about abusing the starter, seems it would be hard turning over a cold engine with thick oil

 

[MolaKule]

I view it this way: The faster the starter turns, the quicker the engine will fire, thus a newer, more powerful battery will get things going quicker. What burns up a starter is how long it has to crank. The longer the starting time, the more internal heat generated, which kills a starter.

Also, make sure your alternator is putting out at least 13.8 volts. Most alternators have temperature sensing devices that allow slightly higher voltages in colder weather. On my Nissan, the voltage is 14.28 volts at idle (750 rpm). Also, make sure the alternator belt is tight.

Patman,

Do you have one of those gigantic capacitors (about 0.5 to farad) to help smooth out power fluctuations for your Megawatt audio system when at idle?

 

[Patman]

I was thinking about doing a cap for my audio system, but I think it might not be needed.
I'm not really going to be putting out a lot of power. The one amp, when set up 4ohms mono,
will probably be about 100 watts going into the 6.5" subs. The other amp is only 25x2 for the
components set. So it's not a major amount of juice needed, at least not enough that I feel
it would need the cap. A fresh battery should do the trick. I should have done a cap on the
system I had in my Mustang. It was 1000 watts and even with a 900cca battery the voltage
would dip into the red with every bass hit, and the headlights would go very dim.

I looked at a second place and still the highest I could find for my car was 700cca. I could buy
one of those Optima batteries but they are expensive! I'm trying to keep costs down.
Walmart has the best deal at about $80CDN for the new Energizer 700cca.

 

[VaderSS]

There are cheaper alternatives to the Optima. Exide's Orbital, and AC Professional Platinum are sealed also. This prevents corrosion around and under the battery.

 

[MolaKule]

Patman,

The reason I asked was that a student of mine came into class one day and said his car was dying at the light when he had his stereo on. Well, I found out this guy had a two-amplifier, 2kW system (with 12 speakers), so that meant he was pulling 166 Amps for a 12 volt system when volume was up (I don't know how he withstood the audio volume).

His alternator was an 80 Amp version, so the battery was being pumped dry at idle.

We finally ran two cables directly from the battery to his two amps and placed two caps at each of the two amps. Now we can hear him arrive as pulls in to the parkinglot before he comes to class!