Is it a battery problem or starter??

And just WHERE does this magical 500 amp load requirement comes from?

I have always known it to be 1/2 of CCA. Not all batteries are 1000 cca. Some are less, some are more. Most batteries peddled are only 750 CCA.

that 50 amp load tester will show a bad battery. It's not a VAT 40, but it will get it done.

 

you have a 900 amp cca battery. you need 450 amps to pull down.

as far as a 50 amp machine. I DON'T THINK SOOOOOOOOOOOO.

yes sir. car battery checks out fine. according to the 50 amp machine. so why won't it crank.

a 4 cylinder car motor pulls 80 amps. 6 cyllinders pull 100 amps. 8 cylinders pull 120-150 amps.

but that great big starter motor on your heavy diesel engine. can UUUUU say 250 amps. TO CRANK. now, how about that initial power just to get the starter motor spinning. A WHOLE LOT OF 500 AMPS JUST TO JUMP START THAT STARTER MOTOR SPINNING.

but that's ok. you can stick with your 50 amp machine. let me know when that 9 volt duracell finally quits.

and by the way, i never said a 50 amp machine WOULDN'T test a bad battery. i just said that you need a whole heck more then 50 amps to accurately test battery.

and every parts store i seen around here testing batteries. are all using that same basic 50 amp machine. NONE of them use the machine in that posted video.

 

News flash for ya.
Most shops use that same $50 tester compared to a $1000 vat40.

And if ya think your starters are only taking that many amps, ya may want to go get an inductive pickup and start taking some base line readings.

Cuz you are way off.

 

SNOWY there are PARTS stores that ACTUALLY know what they are doing and have the correct equipment to do the BIG stuff , too bad you never found 1.

The place I suggested to the OP does HEAVY DUTY equipment batteries not just cars and flashlight batteries.

 

Are you guys really arguing with Snowy?? You must be bored lol

 

well, here's a news flash for yall.

i did 2 years community college. the 1st quarter was part batteries, starters, and alternators. yes they have the big machine.

and sorry about yalls luck. but i actually used that big machine to see what the amp draw on starters was.

you cccccc's. i'm a retired ASE certified auto tech. did mechanics for 12 years. before becoming a truck driver.

i never said a 50 amp machine couldn't test a bad battery. but 90 percent of tests done with that machine WILL show good. becuase that 50 amp machine can't compete with what a starter motor ACTUALLY pulls.

that 500 magical number comes from what A REAL MACHINE can do. like the vat 40. walmart now sells a battery that claims to be 1100 amps. 950 cca. so yeah, 425 amps to test that battery for 15 seconds.

i went to community college. i did the profession. and apparently was i smart enough to become ASE certified. by passing there tests.

where DID YOU ALL get your training???

the only real good that 50 amp machne can do is 100 cca batteries. don't think your gonna find a battery that weak unless your testing a moped.

and i see autozones and o'reillys testing batteries all the time. in the car. with that 50 amp machine.

BTW. i DOOOO have a volt meter with an inductive pickup. todays results are no different then 1988 when i used the big machine. you can buy em at an auto parts stores.

 

good point.

 

Even the parts stores would tell me their tester wasn't really that good for the larger batteries, but most batteries are small these days.

I'm wondering what kind of equipment the truck dealers are using.

 

That could be just a bad ground if the batteries are new. If the ends of the cables have expanded, then there's probably corrosion creating resistance.

 

SNOWY get it in your HEAD there are PLACES that actually know what their doing ( they went to SCHOOL as well ) and have the correct equipment just do not go to PEDROS Truck parts and TACO stand.


Besides in Ontario Canada the OP's location its required by LAW to have a 5 year aprrenticeship + trade school and a MECHANICS license unlike in the USA where ASE certification is usually required (not by law but by employers)