Snap-On YA2612A battery tester problem

[jvitez]

I bought this Snap-On battery tester last year from a fellow GJ member to replace an old style carbon-pile tester. I have multiple batteries in multiple vehicles so I always seem to be doing something to batteries.

I was checking a Group 49 1025 amp 12V flooded lead acid battery (NAPA maintenace free) again today. I had it on a Battery Tender all winter, checked it last week with the battery Tender removed, and the YA2612A read 24% capacity, ie replace. I left the battery alone all week. I was going to replace it today but thought I'd check it again. Today it reads resting voltage of 12.7V, and an 84% capacity, ie good! So I checked it again 5 min later, and now it reads 94%. Huh? Garage temps have been the same all week. The battery is in the vehicle properly connected to the battery cables, though there is some built up corrosion on the neg terminal.

The SO website lists no owners manual available for the tester. Is there a battery within the tester that might need replacing? Or does it use the tested-battery's current to run the testing circuitry? Does how I connect it to the battery matter? Are you supposed to use this with the battery cables disconnected? Would the neg terminal corrosion cause unreliable readings?

Anyone else use a YA2612A? Anyone else have this experience? Help!

 

[redwrench60]

You really need to remove both cables and test right at the battery posts. If it's a side post don't use bolts as test adaptors use actual side post charging adaptors instead. Install the leads on the posts and give em a twist to ensure a good connection. And yes corrosion on the terminals will effect test results.

 

[richfinn]

How are you removing the surface charge?

To be on the safe side I would say charge the battery for at least 15 mins with the engine running, switch off and then turn on the headlights for at least 1 minute and then wait for the voltage to stabilise and don,t test anything below 12.2v.

If this is a conductance type tester you dont need to fully charge the battery to perform a test 15mins on the alternator is sufficient.

If you still cant produce a repeatable result after 3 attempts, condemn the battery by taking into consideration its age/the type of use its had/your charging and drain tests.

Or bench charge it and have checked on a carbon pile tester.

Conductance testers are the future unfortunately (manufacturers all now recommend this type of tester as they cope with all types including AGM) and their is a learning curve.

 

[fatboy99]

The mid tronics tester we have at work is like the tester you have. And it will give you different results if the terminals are corroded even a little. take the cables off and clean the post and see what results you get. Not sure if the Snap On is as sensitive as the mid tronic but worth a try.

 

[jvitez]

Thank you gents! Before doing a carbon pile bench test I would remove the battery (of course!), then clean the terminals, ensure the electrolyte level was correct if I could get to the cells, then fully charge it. This Snap-On tester is so easy to use and doesn't require a full charge, that I forgot about the others parts of a proper test, including the surface charge. Thanks for the reminder!

What sort of documentation came with your testers? I wish I could get an owners manual for mine, unless it never came with one. Anyone know if it did?

 

[redwrench60]

It would have come with an operator's manual but there's nothing you don't already know Sounds like you have it whipped.

 

[jvitez]

Here's a follow-up.

I removed the battery, cleaned the corrosion off the battery posts, cleaned the case with baking soda and rinsed it well, used a battery tool to shine up the posts and the car's cable terminals. Then put the battery on my Battery Minder charger until fully charged. Let it sit overnight. Tested it again, and.......



99% capacity! Yay!!

I just saved myself the cost of a new battery. Thank you Snap-On, and thank you gents!

 

[Yahiko]

Not to dig up and old thread and make it into a zombie-thread.
I have a question for you. How did the life of the battery so over time
after you did the cleanup? Do you still use the YA2612A tester?
The reason I ask is I am looking at one and the Google link showed
this thread when looking for a manual. Good Old Google. It's mind is going.
Anyway Should I look at the Snap-On YA2612A or just pass on it and
keep looking for a carbon pile?

Thanks for the help.

Sean

EDIT : Ouch I thought I had posted before this.