Autocraft Gold 51R: Tronton Battery Tester Results

[gathermewool]

Battery: Autocraft Gold, size 51R, 500CCA
Battery Date: 7/2013 (I wrongly listed the battery as 3-4 years old in a previous thread)

Background:

1. Battery is used in DD (2008 Civic LX)
2. 15 miles one-way commute
3. Never idles to warmup
4. Never left with loads on, engine off
5. Drained to dead once: left light on after getting back from travel; noted dead battery 36 hrs later
6. Immediately charged battery to full using 6A/2A Schumacker charger, followed by BatteryMinder Plus
7. Some very slow starts in -10F weather; immediate starts in anything > 20F
8. Charged battery from this past Friday night until this afternoon (~36 hrs)
-----a. On Schumacker's 6A mode (~16.1VDC), almost immediately began to gas (bubbles)
-----b. Switched Schumacker to 2A mode (~14.5VDC) and a small amount of gassing was still evident, but very little.
-----c. At ~13.5VDC on BatteryMinder Plus, no gassing was evident.

Battery Tester: Tronton 125A Battery Load Tester (cheap Northern Tool tester I picked up on sale not long ago)

Display and Selection Features:

1. Battery status indicator LED lights: indicates green (GOOD), yellow (WEAK), and red (BAD) status

2. Display (digital)
-----a. Indicates CCA selection: depressing the 'SET CCA' push-button will cycle through and allow selection of CCA (200-999)
-----b. Indicates battery voltage

Principal of Operation:

Tester is powered only by the test battery and works by energizing heating element (resistive load) for 5 seconds (listed as 125A), with the following precautions:

1. Wait 1 minute between tests for cooldown

2. Do not test more than three times in five minutes

Test Sequence:

1. Initial open-circuit battery voltage, immediately after charging 36 hours, was > 13.2VDC (surface charge)
-----a. Upon attaching the Tronton battery tester, the displayed indicated 13.2VDC
-----b. Battery status indicated as red (BAD) and would not allow me to change CCA nor initiate testing
-----c. After waiting for surface charge to dissipate down to 13.0VDC, battery status changed to green (GOOD) and selection of CCA was allowed. This must be an internal interlock, to prevent operation of the tester while the engine is running.

2. Set to 500 CCA by continually depressing the 'SET CCA' push push-button until 500 was displayed

3. Initiated test by depressing and immediately releasing the 'TEST START' push-button:
-----a. Battery voltage, as indicated on the Tronton display, rapidly lowered to 10.5 VDC and remained there for remainder of the five-second test
-----b. For the duration of test, the LED indicator changed to yellow (WEAK)
-----c. The Tronton heater elements became red hot, as seen through the vent slats.
-----d. START and END of test was evidenced by loud relay clicks (subjectively: sounded very solid, FWIW)

4. Immediately following the test (the relay clicked OFF and the heating element began to cool), the display goes through a little light dance that lasts ~10 seconds
-----a. No voltage is displayed, since the LED that would display the voltage are dancing around
-----b. Battery status indicator remains at yellow (WEAK) for the duration of the display LED dance
-----c. Fluke indicates slowly rising voltage as soon as the test is over, when the relay clicks OFF

5. Immediately following the display light dance, voltage indication returns:
-----a. Voltage displays 12.4VDC
-----b. Battery status indicates green (GOOD) status

6. Battery voltage recovers quickly to 12.6VDC within minutes

7. Repeated test 3X, with one minute between tests: results were the same for each test.

8. Fluke indicated min voltage of 10. 55VDC during test

9. Fluke indicated recovered voltage of 12.61VDC following test and before subsequent test

10. Fluke indicated close to Tronton tester voltage (with the Fluke having one more decimal place indicated)

Conclusion:

The instructions tell you how to start a test, but lacks in how you're supposed to interpret the results (it doesn't actually display anything other than a voltage indication and battery status light color, so I'm hoping some of you can help me out.

It seems as if the quick recovery to 12.6VDC following the test and change to green (GOOD) indication immediately following the display's little "I'm analyzing the data" light dance it does, is a good sign, but it doesn't really say so.

 

[JHZR2]

10.5V conduction under load is 1.75v / cell. Not terrible but not high either. Did the battery get loaded with a constant 125A or what?

You can calculate dc impedance from loaded ops and compare to new batteries of similar size to see where you're at.

 

[gathermewool]

I believe the tester literally energizes the heating element for five seconds and then deenergizes it. I can't verify the actual load current, and resistance will change as the element heats up, but it should be relatively constant. If you're asking if this tester has any logic to vary load, then I'd guess no.

I'm not sure when I'll get the chance, but it would be interesting to compare results with a brand new battery. If I have the opportunity to do so, I'll post up results.

 

[gathermewool]

Also, if you had to guess, what would you think voltage should drop to, under ideal conditions?

 

[901Memphis]

You really need to ditch that battery cooker 6/2 Schumacher

 

[gathermewool]

Originally Posted By: 901Memphis
You really need to ditch that battery cooker 6/2 Schumacher


Could you elaborate? It seems to do the job I use it for quite well - to be used as a bulk charger, in the VERY rare case that I need to quickly charge (compared to a maintainer, I mean) a depleted battery. I've probably only used it a dozen times since buying it ten years ago.

If I do use it as a top-off charger, it's never for extended periods of time. I used it to fully charge the subject battery, when I accidentally drained it, and I used it earlier to top off the Subie battery, in the 2A setting, which maintained a voltage pretty close to what the alternator is putting out, IIRC. Edit: the battery is on the BatteryMinder Plus now, for an over night maintenance charge (hasn't been charged all winter, other than by the alternator.)

 

[Donald]

Its a good bet its a 125 amp load and by plugging in the CCA they roughly calculate the state of the battery.

A much better test is for 50% of the CCA for 15 seconds then read the voltage.

What was the temp when you were charging and taking the test? The BatteryMinder Plus is not temp compensated and not sure about the tester. So the battery was probably not fully charged and if it was cold the test would produce a lower voltage than if it was 70F outside. So the test also needs to be temp compensated.

 

[gathermewool]

Originally Posted By: Donald
Its a good bet its a 125 amp load and by plugging in the CCA they roughly calculate the state of the battery.

A much better test is for 50% of the CCA for 15 seconds then read the voltage.

What was the temp when you were charging and taking the test? The BatteryMinder Plus is not temp compensated and not sure about the tester. So the battery was probably not fully charged and if it was cold the test would produce a lower voltage than if it was 70F outside. So the test also needs to be temp compensated.


Yep, that's probably right, since a heating element is pretty easy to design for a certain amperage load. I'm not looking for perfect, but I would like to understand how to interpret the data produced by my imperfect tester, to give me a gross check of condition. It would also be good to know if this tester is more accurate than a typical non-loading tester.

Also, the test I performed was after charging the battery for 36 hrs in my basement, so the battery was fully charged.

The load test was also performed in my basement. The temperature was >60F, maybe even as high as 70F (darned leaky, ancient furnace...) due to warmer weather outside.

 

[Donald]

I think it's a reasonable tester. If it fails that test you know it's bad.

The carbon pile testers from HF are reasonably priced.

 

[gathermewool]

Originally Posted By: Donald
I think it's a reasonable tester. If it fails that test you know it's bad.

The carbon pile testers from HF are reasonably priced.


Would you mind pointing me in the direction of a reasonable one that you'd recommend?

 

[gathermewool]

repeated the test and recorded the results. Thoughts?

When put back on the Prologix charger it shifted from charge to desulphate mode very quickly. I don't know exactly how long it took, but when I came back an hour later it had changed status.