Anybody know about battery load testers

[Industrial Toys]

I have a princess Auto Digital Style Load Tester. A friend of mine who deals in a lot of batteries keeps giving me used batteries that are "supposed" to be good. A got about eight different ones lately, and after charging them to around 13 volts for days on a small Schumaker charger ,my tester shows all of them FAIL, even at very low CCA settings.

Is my tester lying to me? All batteries pretty much read ten point something volts almost immediately when the device applies load, then shows fail.

So I did several things. Firstly let me say that the device does not change load resistance, only changes the time the load is applied to the battery based on CCA ratings. Is this a poor way of measuring different size batteries?

I checked the voltage measured my the tester with a fluke meter and believe the tester is accurate.

I measured, the current going through the tester with a Fluke clamp on DC meter and got a reading of 100 amps at the ten point something volts.

So my question is. If one puts a load of 100 amps on a good battery, is it normal for the voltage to drop to ten point something volts or is that too low?

 

[firemanmike69]

I have a big one at work, we test batteries that are fully charged to half the CCA rating for 15 seconds. It has a chart on it for pass/fail I'll look at it tomorrow but I'd think that dropping instantly to 10 volts with a 100 amp load isn't good

 

[davesl708]

I have a princess Auto Digital Style Load Tester. A friend of mine who deals in a lot of batteries keeps giving me used batteries that are "supposed" to be good. A got about eight different ones lately, and after charging them to around 13 volts for days on a small Schumaker charger ,my tester shows all of them FAIL, even at very low CCA settings.

Is my tester lying to me? All batteries pretty much read ten point something volts almost immediately when the device applies load, then shows fail.

So I did several things. Firstly let me say that the device does not change load resistance, only changes the time the load is applied to the battery based on CCA ratings. Is this a poor way of measuring different size batteries?

I checked the voltage measured my the tester with a fluke meter and believe the tester is accurate.

I measured, the current going through the tester with a Fluke clamp on DC meter and got a reading of 100 amps at the ten point something volts.

So my question is. If one puts a load of 100 amps on a good battery, is it normal for the voltage to drop to ten point something volts or is that too low?[/QUOTE]

First the test unit is probably right. They are getting rid of the batteries for a reason.
A 100 amp load is about what a starter would draw.
Most likely the tester is detecting an internal short between the plates.

 

[SPYDERLK]

I have a princess Auto Digital Style Load Tester. A friend of mine who deals in a lot of batteries keeps giving me used batteries that are "supposed" to be good. A got about eight different ones lately, and after charging them to around 13 volts for days on a small Schumaker charger ,my tester shows all of them FAIL, even at very low CCA settings.

Is my tester lying to me? All batteries pretty much read ten point something volts almost immediately when the device applies load, then shows fail.

So I did several things. Firstly let me say that the device does not change load resistance, only changes the time the load is applied to the battery based on CCA ratings. Is this a poor way of measuring different size batteries?

I checked the voltage measured my the tester with a fluke meter and believe the tester is accurate.

I measured, the current going through the tester with a Fluke clamp on DC meter and got a reading of 100 amps at the ten point something volts.

So my question is. If one puts a load of 100 amps on a good battery, is it normal for the voltage to drop to ten point something volts or is that too low?

You are measuring the V directly on the battery terminals right -- NOT from the clamp on the terminal? ... I agree 10V @ 100A is too low. I would expect 11.5 or better with the probes directly on the terminals.
larry

 

[Industrial Toys]

My gut feeling is that the batteries are no good. I know, I should just try to test some known good batteries. I wonder at what voltage the tester is passes the battery.

The other thing is that my charger only seems to charge to 13 volts, not 13.8. This can't help the situation. Maybe if the battery was .8 volt higher in charge the tester would OK it.

If the batteries are no good, I just don't understand how a guy who works with batteries day in and day out, and maybe handles a couple thousand a year could be so wrong! Some of the batteries looked as if they had clearly been in service for a while but the latest two looked brand new!

I don't have too much good to say about Princess Auto stuff, much like HF, but I always liked that Digital tester. Maybe I would have been farther ahead with the old dial type. Get a better feel for battery voltage under load. The one I bought before that, I just remembered it now, was a carbon pile tester. It went snap, crackle and pop the second time I used it! (Typical).

 

[tcartwri]

A good battery will make one of those testers smoke if you hold it for 15 seconds.

 

[2458n]

I just went through the battery testing routine today. Took my bad battery to Autozone to be charged and tested. Well they skipped the charging part and put a hand held load tester on it. Battery tested bad was only at 80%. How could they test it if they did not fully charge it? Manager was showing trainee how to sell a battery. Took mine and went home. Back to the junk yard where I had bought the group 65 battery for 20.00 dollars. They charged it for 3 hours and it really did fail. Autozone wanted 137.00 with exchange for a two year battery. Or I could have 0ne from behind the wall for 45.99, this was supposed to be one where someone bought a battery and then found out that they really needed a new alternator. The store took the battery back ,but could now not sell it as "new". Kubota now has a new junk 20 dollar battery from the yard. Back to your supply of free battery- at least the guy is trying to set you up.

 

[k0ua]

Lets discuss "bad" and "badder" batteries. A battery that holds 10.5 volts at 100 amp load is Not bad for some applications, but might not be all that good for cranking over a diesel tractor for instance in the middle of winter. I think some starters would draw more than 100 amps. But the battery could be used for other things like a smaller engines starting battery or to run radios or other things with a trickle charger on it to recharge it. So a battery with a high internal resistance that these batteries seem to have, could still be used for many other things.

 

[Industrial Toys]

On the bright side, I did get a nice big HD one, that has worked well since, a couple of years back that came out of a Police Cruiser. They were doing some "Green" project for anti idling and somehow the battery became surplus. I needed it because I had not bolted my battery down in my Kubota Loader, was working on soime wild inclines and the battery fell against the exhaust manifold! Not a good day!

I really only need one lesser battery to run my 12 volt fuel pumps. I just got rid of a couple of undoubtedly very expensive glas-mat batteries that were also "supposed" to be good. I had a special charger/conditioner but could not bring them back up to be starting batteries. Again, they showed full charge and would instantly go down to (again) ten point something volts.

I wonder what makes a Huge battery that has full voltage, lack any capacity at all. Is it simply sulfation? Most of these batteries I get have been used in commercial mobile Inverter service, so have usually seen a lot of charge/discharge cycles and maybe even discharged completely!

 

[skyhook]

IT, check out this test, pay close attention to question 11.
Once you put in an answer, it will tell you if your right or not.
I think you'll find this useful.

Online Practice Questions - Batteries

 

[Sodo]

Some fellas have tricks for healing batteries. Not every battery can be healed, one in 5 is wishful thinking but if a battery guy says they're good you may have better odds. Sometimes thumping lightly on the ground can settle the heap of sulfation and can un-short the plates. But it could shake off a new pile of flakes too. Especially if its been tipped over - try to "settle" it.

Typically you need higher voltage to shock a battery back to life, like 15.5v. If it won't take any charge give it a blast with the engine-start feature (some chargers). And if you do revive a battery you usuall get only another year or two. Not good for your primary vehicle. Sounds like you could use a good battery charger that has battery "re-condition" features. But keep your old charger, sometimes a smart charger will refuse to try whereas a dumb old charger is what you need to revive it.

You won't make a living reconditioning batteries you have to think of it as fishing wher if yo're still hungry there's slways McDonalds on the way home.

 

[newbury]

And remember there can be uses for marginal batteries -
Hook one up to a battery maintainer and a 12 Volt LED light for an "emergency light" in the shop.

 

[Sodo]

I have that setup, solar panel charging it, running 12v LEDs in my barn.

The battery is 10 years old. Removed (at work) because someone left a light on in the truck and it went dead and it was 7 years old, and nobody cares about spending company $$. And nobody wants to be the one who said "that battery is fine". Now its 10 years old, and always has 12.5v, and its fine (for its current job). And the truck aint stuck. And I always have (some) light in my barn.

 

[Soundguy]

To the op, what's that tester say about your car/truck bat in your vehicle. Use that as a control.

 

[k0ua]

And remember there can be uses for marginal batteries -
Hook one up to a battery maintainer and a 12 Volt LED light for an "emergency light" in the shop.

Exactly. It could be very useful in that service.

 

[Industrial Toys]

Actually I have a small florescent light in my shop that is connected to my alarm panel battery. I installed it to have light, years ago when trying to hook up a PTO genset during a power failure. Beats a flashlight, when your hands are engaged!

I would still like to know, if merely changing the set load time is a realistic means of changing the CCA reading of the tester.

I took that test, very informative. Didn't do very well at first, but got better toward the end.

I was thinking last night. The bigger of the two batteries is almost 1000 CCA. Putting a 100 amp load on it should not even phase that bugger if he were healthy! It has pryable valve caps and just for laughs, if I have a moment I will check out the juice in the battery with a hydrometer.

I checked a known good, albeit not huge battery (550cca)that I bought new last summer for my Diesel Steiner. It hasn't been run for a week or so in this terrible cold. It showed 12.6 volts and went to 10.4 on a 500 cca setting and immediately showed weak. And in this regard I must apologise. All my readings were showing weak, not fail! I have never seen the unit show fail. Usually it just quits!

I should put the Steiner battery on charge and check it later.

I have one of those big cheap trickle/charge/boost chargers. I don't use it often. It lacks a timer that some of these units have and I should put one in. I have many, that I always pick up at Habitat For Humanity, cheap! Anyway, what I really wanted to say, is that I just noticed the other day, that on Boost, this charger only puts out something like 7 volts! Don't quote me on that (exactly), but I found that really, really low. I have never been able to start anything with that thing. Heck, the leads and clamps are a complete joke! Letting a small charger put a surface charge on a battery even for five minutes seems to be more effective.

 

[Dave M7040]

IT, check out this test, pay close attention to question 11.
Once you put in an answer, it will tell you if your right or not.
I think you'll find this useful.
Online Practice Questions - Batteries

Skyhook
Tried the test and found it a great reminder of thinks long forgotten.
Dave M7040

 

[DFB]

Skyhook
Tried the test and found it a great reminder of thinks long forgotten.
Dave M7040

Yes I liked it too. Missed 3 but I hadn't finished my morning coffee yet either

 

[SPYDERLK]

2 of the answers contradict one another.

 

[skyhook]

2 of the answers contradict one another.

What two.