Lead Acid Battery Analyzers. Working principle? - Page 1
Forum section: electronics / general

author: rvalente
author_rank: Frequent Contributor
timestamp: November 27, 2017, 02:50:35 pm
content: Hello Mates,does anyone carry any papers or knows about how these Lead Acid Battery Analyzer working principles?They measure internal resistance, Cold Crank Amps (in various standards). Have small gauge cables for this much current and appears to use Kelvin probes.Cheapo Aliexpress stuff:Hioki BT3554Fluke 500 are similar...

author: ogden
author_rank: Super Contributor
timestamp: November 27, 2017, 03:15:33 pm
content: Quote from: rvalente on November 27, 2017, 02:50:35 pmUsually most of them do just voltage and internal resistance. Maybe those aimed at car battery testing, do cold crank amps- dunno.Hioki BT3554 specs briefly describes how internal resistance measurement is done: Testing source frequency: 1 kHz ±30 Hz, With function for avoiding noise frequency enabled: 1 kHz ±80 Hz, Testing current: 160 mA (3m/30 m\$\Omega\$ range), 16 mA (300 m\$\Omega\$ range), 1.6 mA (3range), Open-circuit Voltage: 5 V peak

author: G7PSK
author_rank: Super Contributor
timestamp: November 27, 2017, 03:32:46 pm
content: I would not rely on one of those as the only sure way to know if the battery is good or not is a heavy load. I had a suspect car battery and they used something like one of those and pronounced the battery good, when it kept not wanting to start the car after the side lights had been left on a couple of hours, the garage wanted to replace the alternator then decided a new starter was in order so I went to anothe place where they had one of the old style testers, basicly a dead short with a volt meter across it, that showed the battery as being poor and in need of replacement.

author: CJay
author_rank: Super Contributor
timestamp: November 27, 2017, 03:47:57 pm
content: I *think* it's a Motorola App not that gives a nice run down on how to test a battery, you can measure and calculate a lot of data about a cell by applying an AC signal to it (bit like, if not identical to, the capacitor ESR testers) but as G7PSK says, while it measures the cell resistance, capacity and charge state, it doesn't load the battery and you can have a battery that shows good but won't reliably crank an engine.Some of the better ones will apply a small load and measure recovery time as well, the older units applied a load of a few tens or even more amps but they're not a little scary to use when they can draw ~100 amps.

author: ogden
author_rank: Super Contributor
timestamp: November 27, 2017, 04:17:12 pm
content: Quote from: CJay on November 27, 2017, 03:47:57 pmYou can have battery that shows nominal voltage, nominal ESR but does not provide nominal current? Is this some kind of fisherman's story?Whatever.That's why there's car battery chargers, car battery testers and then there's industrial devices - inverters and UPS'es, testers as well. Original Post does not tell what kind of batteries shall be tested. Only Aliexpress "el cheapo" seemingly is aimed at car battery testing. Both Hioki and Fluke testers are aimed at industrial use - they indeed measure all you want to know about UPS lead acid batteries, without "cold crank" or load test.

author: Nusa
author_rank: Super Contributor
timestamp: November 27, 2017, 04:28:03 pm
content: There's a lot to be said for the simple and cheap hydrometer to check the specific gravity of the acid in each cell in the battery.

author: CJay
author_rank: Super Contributor
timestamp: November 27, 2017, 04:41:42 pm
content: Quote from: ogden on November 27, 2017, 04:17:12 pmNope, have seen it, batteries that pass the low current tests from the 'fancy' testers as good but fail when you hit them with a heavy load, I've heard a few explanations including cracked interconnects which seem the most likely to me.I would trust the ESR testers (I used to sell them) but just occasionally, they can be fooled.I used to design and sell garage diagnostic equipment, in addition to Bear, SPX and Sun we used to sell a few home grown designs and a few items from European companies so I've been around a *large* number of workshops across the UK as well as the workshops of a UK wide fast fit chain that we had sole equipment supply contracts with.

author: ogden
author_rank: Super Contributor
timestamp: November 27, 2017, 05:37:05 pm
content: Quote from: CJay on November 27, 2017, 04:41:42 pmCracks?! Please realize that batteries are used not only on automobilesQuoteGood. No doubt you know enough about car batteries which indeed needs car battery testers. I've been around quite enough industrial UPS'es instead. "Fancy" 1KHz ESR tester like Fluke 500 for SLA and deep cycle batteries works well - no need for cold crank testNot all lead acid batteries are equal. Automotive batteries quite differ from those used in emergency backup applications.

author: CJay
author_rank: Super Contributor
timestamp: November 27, 2017, 06:55:23 pm
content: Quote from: ogden on November 27, 2017, 05:37:05 pmAre you claiming infallibility for the FLuke?

author: Freelander
author_rank: Regular Contributor
timestamp: November 27, 2017, 07:16:27 pm
content: I don't believe any of them are particularly 'special' however they perform an IR task that is nigh on impossible to accomplish otherwise.When testing SLA batteries and various deep cycle batteries, it is not appropriate to heavily load the battery. The batteries are not designed for the types of loads as per the normal 'car' / automotive battery. The thin plate / high current automotive batteries are only designed to give intense bursts of power for very short periods. They are not designed for sustained light / medium loading and will in fact be damaged more rapidly by such usage.SG was and still is a gold standard in battery testing however, it is time consuming, can be messy, often has difficult access and indeed, not a lot of modern batteries evenhaveaccess or indeed wet cells. Various 'maintenance free' (read disposable) and absorbent mat units are around. Many 'dealers' and garages use the BBB meters (Bulshit baffles brains) that give a nice little printout to the owner. These mostly rely on 5 thing only. Voltage at start of test, voltage on load engine off, voltage at engine cranking, voltage with engine running (usually above 2k rpm) and internal resistance approximation. All the voltage checks can be completed in seconds by a spanner monkey but the internal resistance check is not available to the 'normal' SM. From the very approximate IR check they estimate CCAcough..... - widely inaccurately . Temperature is noted to apply fudges to calcs, ambient and DUT however DUT is hardly ever probed for temps due to CBA factor. which is a shame - as it can get fairly toasty in a car engine bay - or indeed the other way where it may be warm in the garage and the battery is still around zero c from the overnight stand before testing.These units do not offer much - if anything - more than the simple tests that we were carrying out 30 or 40 years ago. Same voltage tests and also (if alternator is ok) disable ignition and crank for 15 seconds with lights on. If it is still ok after that, it is a good battery..Any battery (LA) that has been taken to below 12V resting voltage will almost certainly be captain cooked and awaiting a nice UK morning in winter to let you REALLY know.(AGM automotive thin plate design units are really good for being able to recover quite effectively from deep discharge / low voltage where a thin plate LA unit would be almost certainly permanently damaged.Specialist units for 'stationary battery systems' only offer 1 thing of real use imho - that being approximation of internal resistance. !. That is the only thing of 'use' that cannot be readily checked with a multimeter - it can be used along with the voltage readings as an approximation of ability to discharge. Even the good old flukey expects a steady load timed discharge test - and heavens above, it can tell you the approximate capacity from this..... so could the monkey holding it...The rest of the functions- take the fluke 500 as an example - can be carried out by any monkey with a multimeter to be honest. It looks good to the client though.. always worth a lot more dosh. Every flashing LED used to be worth 25 quid on top of the hourly rate... now it is a bit of simple data logging PC software that is nothing more than could be accomplished with a spreadsheet with the most basic of calcs in. Plotting a baseline - for anything really - should be automatic for anyone in the business. You then have something to refer to.I really see nothing of any great value apart from internal resistance approximation. But hey.. it looks flash and the BBB meters and boxes definitely add an extra zero to the invoice.- KerCHING ....like most things 'techy' these days it is mostly a case of an expensive solution looking for a problem.Actually, to be serious, It does certainly have a place in checking safety backup and stationary units. It can be delegated to a junior monkey (within reason) and the pc / laptop whatever makes the notes and reading. So there is a use I suppose.. It also offers an IWM feature for the bosses in the event of the excrement hitting the rotary oscillator . An IWM unit is where, because of the expensive device you got the DIrector / manager / company to pay for, you can blame the device and not yourself ..... "IT WASNT ME" ...................

author: ogden
author_rank: Super Contributor
timestamp: November 27, 2017, 08:43:50 pm
content: Quote from: CJay on November 27, 2017, 06:55:23 pmIndeed. Fluke 500 is very dependable if used for what it is made. BTW I never suggested that (hi-current) car battery shall be tested using such kind of toolFor reference:http://en-us.fluke.com/products/battery-analyzers/Quote: "Fluke Battery Analyzers are the ideal test tool for maintaining, troubleshooting and performance testing individual stationary batteries and battery banks used in critical battery back-up applications in data centers, telecom networks, power distribution systems and more. "

author: Rerouter
author_rank: Super Contributor
timestamp: February 18, 2019, 08:49:04 am
content: The ones I have seen are pretty much jumper leads with a sense line (not true kelvin but close enough) and a high power switch to a load of about 0.1 ohms, measure the resting voltage, switch on the load, wait 2 seconds for the float voltage to dissapear and measure the loaded voltage, voltage drop under load gives you the internal resistance and lets you see if it can handle cranking.The more fancy ones can look at how long the float voltage hangs around for or if it momentarily dips etc, you can even see the float voltage stair step down if some cells are running dry as they go first.

author: bluey
author_rank: Regular Contributor
timestamp: March 03, 2020, 08:01:22 pm
content: Ansmann kfz power check (12 euros) describes the working principles in the manual.https://www.ansmann.de/en/accessories/kfz-power-checkhttps://www.ansmann.de/uploads/Import/docs/manuals/4000002_Kfz-Power-Check_Manual.pdfIt uses the vehicle systems to charge and load the battery. Voltages for success and failure are described in detail in the specification. The tester turns the voltage into a colored led. Sounds eminently sensible. So i just need my voltmeter and a vehicle. No other equipment required.QuoteThis japanese one has the led values on the case, but is a lot more generous with the threshholds.https://d10b75yp86lc36.cloudfront.net/Monotaro3/pi/full/mono35476813-101202-02.jpg