Why Battery Voltage Varies Between Different Testers? - Page 1
Forum section: electronics / general

author: Boris_yo
author_rank: Frequent Contributor
timestamp: September 18, 2022, 04:12:06 am
content: Hi. Tested new alkaline battery 1.5v and here are the readings I got:1. Chinese battery tester: 1.27v2. Aneng brand Chinese battery tester: 1.50v3. Chinese multimeter: 1.53vUsed lithium AA single-use battery:1. Chinese battery tester: 1.23v2. Aneng brand Chinese battery tester: 1.48vTested Sanyo 2500mAh barely charged AA battery:1. Chinese battery tester: 1.03v2. Aneng brand Chinese battery tester: 1.11vTested 9v alkaline rectangular battery:1. Chinese battery tester: 8.85v2. Aneng brand Chinese battery tester: 9.12vIt seems that while multimeter puts on zero load, the battery testers put a tad bit. Though why readings between both battery testers vary?

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: September 18, 2022, 04:30:35 am
content: Are these 'testers' analog meter variety? The cheaper the meter component the more inaccurate they are.A analog meter is supposed to considered *most accurate at FSD (full scale deflection). Connect them to a good variable power supply and set the output to what the maximum range the meter should read. If that is anywhere near accurate, then check the meter at 1/4, 1/2, 3/4 range to see how good it is.edit: most

author: WattsThat
author_rank: Frequent Contributor
timestamp: September 18, 2022, 04:32:22 am
content: Yes, battery testers load the battery, a multimeter/DMM does not.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: September 18, 2022, 04:36:17 am
content: Quote from: WattsThat on September 18, 2022, 04:32:22 amI see now the question asked. Disregard my answer. Sorry.

author: tooki
author_rank: Super Contributor
timestamp: September 18, 2022, 04:33:24 pm
content: Quote from: Boris_yo on September 18, 2022, 04:12:06 amYes, a multimeter places essentially no load, while a tester places a load. As for the differences — well, think about it for a moment: what would cause a difference in measured voltage? Give us your hypothesis and we’ll let you know if it’s right.

author: bdunham7
author_rank: Super Contributor
timestamp: September 18, 2022, 05:01:13 pm
content: I think your generic or unnamed "Chinese battery tester" is the one getting the job done here...

author: ledtester
author_rank: Super Contributor
timestamp: September 18, 2022, 05:05:51 pm
content: Which one is your Aneng tester? Does it look like this:

author: BeBuLamar
author_rank: Super Contributor
timestamp: September 18, 2022, 09:07:37 pm
content: Connect a power supply set for 1.5V with rather hefty current capacity (at least 2A) and see what the #1 tester reads and how much current does it draw from the power supply.

author: unknownparticle
author_rank: Frequent Contributor
timestamp: September 19, 2022, 05:57:51 pm
content: Some DMM's have a dedicated range for 1.5 and 9 volt batteries, which place a load across the cell. This gives a more realistic idea of the cell capacity.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: October 04, 2022, 08:46:32 am
content: Quote from: tooki on September 18, 2022, 04:33:24 pmImpaired conductivity of battery tester? I used electronics contact spray on the one giving lowest reading and it still does. Probably has some kind of internal resistance or crappy components.Quote from: ledtesterThat's the one. Also here's the multimeter face. For voltage reading I set on 2 under V-

author: Nominal Animal
author_rank: Super Contributor
timestamp: October 04, 2022, 11:48:15 am
content: Quote from: Boris_yo on October 04, 2022, 08:46:32 amNo. A battery is not a perfect voltage or current source, it has real world characteristics. Consider what those characteristics are.

author: SmallCog
author_rank: Frequent Contributor
timestamp: October 06, 2022, 01:53:49 am
content: I suggest you probe the battery with the meter whilst it's being tested by the battery tester.Theoretically you'll see more similar readings between the meter and tester as the meter will be reading the loaded battery

author: Kasper
author_rank: Frequent Contributor
timestamp: October 06, 2022, 05:10:01 am
content: Measure the battery current during the battery test to check for differences between testers.

author: tooki
author_rank: Super Contributor
timestamp: October 06, 2022, 06:21:22 am
content: Quote from: Boris_yo on October 04, 2022, 08:46:32 amNo, it’s not that.Quote from: Boris_yo on October 04, 2022, 08:46:32 amEarlier, you mentioned the battery tester applying a load. That is correct. Now, what poses a higher load (= more current flow): a smaller resistance or a larger one?

author: Boris_yo
author_rank: Frequent Contributor
timestamp: October 10, 2022, 06:40:04 am
content: Quote from: tookiAre you talking about resistance of battery or impedance of battery tester?

author: tooki
author_rank: Super Contributor
timestamp: October 10, 2022, 01:30:55 pm
content: It’s a general question to see if you understand Ohm’s law.