charging/starting/battery tester? slightly OT

[northern piper]

So over the past little while I've run into a couple of problems with my 2 different vehicles and I've pulled out my digital Fluke volt meter and fiddled a bit. I had to go and get the battery tested on one vehicle and the guy used an old pile style load tester. I'm wondering if anyone has a battery checker like the one here http://www.midtronics.com/home/products/transportation/batterytesters/pbt200.aspx
or something similar? I'd kind of like to be able to test batteries, charging, etc and these digital meters seem ideal.

Any thoughts?

Piper

[Selectron]

I first used a conductance tester about a decade ago and although initially wary of them, I quickly learned they're far superior to the traditional load tester, so given a choice today I'd choose the conductance tester every time.

At that time I was working for a large telecommunications company, where I had my own workshop doing component-level electronics repairs. Whenever something arose which didn't quite fit into anybody else's remit, it would often be shuffled in my direction, and so one day I found myself responsible for setting up a battery testing and maintenance program for the several thousand sealed lead-acid 12V batteries which were fitted in the street telephony cabinets, where they spent most of the time on standby, float-charging, but would automatically switch into circuit and power the equipment in the event of a mains power failure. Most of the batteries were 37Ah, with the remainder being 65Ah, and they were fitted in banks of four, connected in series to give a nominal 48VDC.

I sourced and purchased some portable load testers, each of which contained a bank of three giant load resistors, fan-cooled, which would draw close to 100 amps and glow red-hot while the battery was under test. The testers had two sets of five LEDs, the first set indicating percentage state of charge from 20% to 100%, and the second set indicating internal impedance, from very high (not good) to very low (good).

Drawbacks were that the battery required to be in a good state of charge prior to testing, so testing couldn't always be performed immediately, and with nearly 100 amps of current flowing, battery explosion was a real risk in the event that one of the inter-cell welds failed and sparked, so as a precautionary measure I had to specify that a protective visor, gloves, apron etc. be worn during actual testing, to satisfy health and safety requirements.

The load tester was effective at detecting batteries which were clearly past their best - unable to accept full charge, or which had developed a high internal impedance, but where it failed quite badly was detecting batteries which were still serviceable but beginning to deteriorate. Many times, a battery would be tested as good, returned to service, then some weeks later during a mains power outage, the batteries would take over, only for service to be lost again shortly afterwards as the bad battery within the bank of four failed, the load tester having failed to detect the early warning signs.

Then one day along came a sales rep. from Midtronics with a little hand-held device called a conductance tester, and that was the first time I'd encountered such a thing. No massive test currents, so no need for the protective visors, gloves, etc. The batteries could remain in-circuit during testing, and this was relatively complex and sensitive digital multiplexing equipment carrying live telephony traffic. We purchased a few of the testers and put them into use and we never again had a false test result - if the tester indicated that a battery was bad, then it was bad, and if it indicated a battery was good, then it would always later prove to be good, and we observed this time and again over the course of thousands of battery tests. The battery under test didn't even need to be fully charged, and several times I did test a partially discharged battery, noted the result, then tested again after charging, obtaining exactly the same result - they really are very reliable devices.

That was all a decade ago, and the Midtronics model which I used didn't have the three LEDs which I see on the model which you've linked to. I recall an LCD display which showed a numeric value which I would then compare to a reference chart, interpreting the reading depending on whether it was a 37Ah or the larger 65Ah battery under test. I assume the three LEDs simplify matters, removing the need to interpret results via a chart.

So in terms of battery testing I would recommend it highly, but you might be disappointed in terms of its charging system and starter testing capabilities - I doubt that that amounts to anything more than the integrated voltmeter function, which would require just some basic knowledge and experience to interpret, a car battery being typically 12.6V off-load, and if the voltage falls from that value after starting the engine then the charging system isn't working, but if it rises to the high thirteens or fourteen-point-something volts then it is working. I doubt it's any more than that but it might be worth e-mailing them and asking, because they do mention "Improved starter / charger system testing".

If they are referring simply to the integrated voltmeter function, then clamp-meter adapters are available which plug into a multimeter on its DC voltage range, enabling the meter to measure high currents without actually breaking into the circuit and inserting a series shunt - simply position the opening jaws of the clamp adapter around the cable in which you want to measure the current flow. So equipped with that, a multimeter and conductance tester, you'd be able to do some serious, meaningful testing on a charging system. I don't think the Midtronics can do it all by itself though.

Oh hold on, I just spotted the link for the manual so I'll have a read. Yes, the charging system/starter testing facility is indeed just a simple voltmeter function, which you already have in your Fluke meter.

[wiswind]

There is a PBT-100 model.....slightly cheaper than the PBT-200, both are for testing batteries with a rated CCA of 200 to 850

Not sure if this would work on a Optima or similar paste/etc style battery, says that it is for "Regular (flooded)" batteries, which is what most of us have.

[northern piper]

Selectron I must thank you for your very thorough and clearly communicated response to my question. While I don't recall having an answer to my usually mundane questions from you directly I've seen many of your posts. I appreciate your time and efforts personally and on this board in general.

I ended up purchasing the Midtronics one here http://www.babcotools.ca/Products/No...ster/MIDPBT300

which was CAN$237.15. An extremely good price. While I understand that a portion of what this tester does can be accomplished by my Fluke meter it's kind of handy to have one tool that'll do most of the testing. I'm forever helping some friend or relative and one less item for me to bring along is a bonus.

Thanks again for your valuable info!

Piper