starting amperage

Thread Starter

96y

Joined May 8, 2019
36
Most full size batteries are about 600-800 cca. BUt they dont use all that on start up. Smaller batteries might be about 350cca.
If you start a pick up truck with a smaller battery will it hurt a smaller battery??as long as it recharges when running..
 

nsaspook

Joined Aug 27, 2009
7,588
Most full size batteries are about 600-800 cca. BUt they dont use all that on start up. Smaller batteries might be about 350cca.
If you start a pick up truck with a smaller battery will it hurt a smaller battery??as long as it recharges when running..
It might eventually hurt the starting motor as the motor will stall longer and get hotter before getting to the proper starting RPM. Less than optimal current can mean the resistive component of the motor impedance remains high, dissipating power instead of the inductive motor component magnetic field transferring starting power to the gear load.
 

Uilnaydar

Joined Jan 30, 2008
118
As points of reference:
  • My 2010 Subaru (2.5l) required a peak of 750A and an average of 250A to start at 78F.
  • My 2001 F150 (4.6l) required a peak of 850A and an average of 350A to start at 68F.
Just happen to have tested some of this stuff :)
 

bwilliams60

Joined Nov 18, 2012
1,343
On average, most automotive starters will have a current draw of around 200-250 Amps. The reasoning behind the extra CCA is twofold. First of all, you need extra amperage to get a stationary motor moving and then the current draw will level out. The extra effort requires a larger battery.
When the cold weather hits, those numbers will rise dramatically. If you look at the CA rating, you will find it to be higher than the CCA rating so don't be confused
Lastly, as a starter draws current, the charge drops very quickly so your starting point needs to be high.
If you want to use a lower CCA battery and save a few bucks, not really, then go ahead and use a smaller battery or an older battery that is not quite rated for your truck. When the contacts in the solenoid weld together and panic sets in trying to undo the cables, you will know the reasoning behind it. Good luck.
 

shortbus

Joined Sep 30, 2009
7,936
If you want to use a lower CCA battery and save a few bucks, not really, then go ahead and use a smaller battery or an older battery that is not quite rated for your truck. When the contacts in the solenoid weld together and panic sets in trying to undo the cables, you will know the reasoning behind it. Good luck.
Most of his post have lead up to this, he has a failing battery and has spent money on supper caps, audio caps ,a "battery tender" now this. If he charged himself minimum wage for all the time online about this he could have bought the correct replacement battery. I'm all for saving money and finding a better way of doing things, but this is just ridiculous.
 

BobaMosfet

Joined Jul 1, 2009
1,208
Most full size batteries are about 600-800 cca. BUt they dont use all that on start up. Smaller batteries might be about 350cca.
If you start a pick up truck with a smaller battery will it hurt a smaller battery??as long as it recharges when running..
Stop. You're confused. CCA = Cold Cranking Amps. This is the amount of current that battery in cold (ie. winter) conditions will output max for a short period of time on instant demand. How much current is actually used is a function of your starter motor. How much it draws to throw the bendix and turn the engine over.

Drawing too much current from a battery (that is a smaller battery not able to deliver the quantity necessary) will usually do damage to the battery - particularly if it's a lead-acid battery. It is always better to have a bigger battery so you have more current, hence longer life in cold periods in case you have to crank several times.

Oh, and by the way, when you first turn it over, it's a dead short because the motor isn't turning. You need a battery that can generate a current spike (starting current must always be significantly higher than current used to turn the motor after) that is able to make the starter turn and keep it turning.
 

Thread Starter

96y

Joined May 8, 2019
36
shortbus...they should kick you off the forum for being anti forum. My other posts have nothing to do with this post. Nothing. I thought AAC had higher standards..
 

SamR

Joined Mar 19, 2019
2,574
There are so many variables here... Hot or cold engine, oil viscosity, manual or automatic transmission, timing, compression ratio, cam lifter pressures turbo booster pressure and on and on... On my old 69 Camaro which had a 350V8 @ 350+ HP small block engine I ended up putting on a big block bell housing and flywheel so I could use a high torque 454V8 engine starter to get it cranked. Even then when the engine was warm I would have to hand retard the spark to get it started and then twist the Mallory Dual Point distributer back to the running timing position once it was fired up and running smoothly. With today's engine starter fob pushbutton EFI computer controlled everything engines it is much simpler. Even so, I would depend on the battery manufacturers recommendation for the particular engine and year model. Dunno what I'm gonna do now that Die Hard has died...
 

SxyWood

Joined Oct 8, 2017
22
Most full size batteries are about 600-800 cca. BUt they dont use all that on start up. Smaller batteries might be about 350cca.
If you start a pick up truck with a smaller battery will it hurt a smaller battery??as long as it recharges when running..
If the battery will start the truck then go with it. The downside is too small of a battery will not last as long as a proper sized battery.

FYI you can’t trust people that cannot spell super correctly. I’ve never seen a supper capacitor. Maybe it is similar to a flux capacitor?
 
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