Anyone used this Jaycar (Australia) battery tester? Any good? - Page 1
Forum section: electronics / general

author: DTJ
author_rank: Super Contributor
timestamp: March 21, 2016, 06:47:34 am
content: I'm thinking of purchasing one of these:http://www.jaycar.com.au/Test-%26-Measurement/Electrical-Testers/Contact/12VDC-Lead-Acid-Battery-Tester/p/QP2261A few of our company vehicles now have maintenance free "sealed cell" lead acid batteries which means I cannot easily check the SG for dud cells. Some of our bigger batteries are >> $200 each.Should I be confident a unit like this will tell me whats going on?

author: GEuser
author_rank: Frequent Contributor
timestamp: March 21, 2016, 02:15:22 pm
content: Nope .But I did read the manual and noticed it had no specs at all , like the test current for instance although being a small gadget it'd get toasty if it was anything large .Most good and LARGE testers can draw a fairly large current to test and probably be more costly too , but that one being very portable still might get the job done ? , so I dunno if its any good .Edited> a foot note.That got me interested so I poked about and looked at several of those types and none have specifications , only the 5 seconds of test is mentioned , so I gather there must be some form of calculation for capacity of battery to the load test .I'm used to the old days in where one had to drag around the battery tester on wheels and there was 2 styles of high and low where high might have been 100+ or so amp for several seconds at 12 or 24v , they had a very large dummy load in them with a BIG moving coil meter to show the results .The one you have asked about actually looks like a good gadget if they work imo .Good luck .

author: DTJ
author_rank: Super Contributor
timestamp: March 22, 2016, 01:45:02 am
content: I've had a bit of a look around and watched a few youtube vids on battery testers.I'm now not sure the jaycar one is up to the task. I think the concept is sound but the implementation might be poor. I'll visit Jaycar and see what the connections to the clamps on the tester are like. They do look a bit flimsy in the pics. I'm guessing a kelvin connection is pretty much essential unless big arse cables are used.I saw one review where the unit had the opposing jaws of the clamps kelvin connected back to the instrument.

author: Unknown
author_rank: Unknown
timestamp: March 22, 2016, 02:37:07 am
content: It's a cheap impedance tester aka 'conductance tester', not a load tester. Doesn't need to have heavy leads or a big load.Haven't played with that one, but in general they're at least as good as measuring SG. For a start, SG won't tell you things like an incipient failure due to a cracking plate or grouping bar (the usual failure modes for car/truck/mobile batteries). Load testing may not either, depending on the size of the load & whether you run a full test to the end-point voltage or not.What they won't really tell you is state of charge, beyond what can be estimated by terminal voltage and impedance. Only real way to do that with a fully-sealed maintenance-free battery is to do a short discharge & compare it to the known discharge curve.(That said, a large number of so-called "maintenance free" batteries aren't fully sealed, & it's possible to access the individual cells under a blanking panel or removable microcellular vent...)

author: djQUAN
author_rank: Frequent Contributor
timestamp: March 22, 2016, 03:13:12 am
content: I have been using the one in the vid for about a year now. I usually purchase used gel/agm UPS cells for solar use. It seems to work well, you can find weak cells easily by looking at the measured CCA or internal resistance. You could even tell if the cells are the deep cycle (slow discharge) or high power (UPS) variety and get the ones more suited to your application.I had a peek at the circuit and it has a beefy SMD mosfet that shorts the battery in very short spikes and measures the resulting voltage and voltage drop via kelvin connections and computes everything else. I could snap a few pics if you like.I suppose a kelvin connection is important and you should get one that has it. Mine does not start the measurement unless a good kelvin connection is made.

author: GEuser
author_rank: Frequent Contributor
timestamp: March 22, 2016, 04:29:19 am
content: I looked about again last night and there is some flash gear out there nowadays DTJ , also read as more expensive , look up Carbon Pile load testers .

author: DTJ
author_rank: Super Contributor
timestamp: March 22, 2016, 06:10:19 am
content: [I looked about again last night and there is some flash gear out there nowadays DTJ , also read as more expensive , look up Carbon Pile load testers .]Yeah I've seen them buggers. You'd probably pick one up cheap at a auto leccy business liquidation sale. A bit on the large side for me, I want something I can toss in the door pocket in my car.

author: vsboost
author_rank: Contributor
timestamp: March 22, 2016, 06:54:23 am
content: I have the Jaycar one, works well for car batteries, did hope it would do smaller 7amp 12v UPS/Alarm batteries but it does not.

author: nowlan
author_rank: Frequent Contributor
timestamp: March 22, 2016, 08:48:37 am
content: There is an SP Tools one on ebay, that looks identical to OP. However costs more with free postage.Ive looked at the Ctek before, and the one in the 2nd video. However, the price of these things can be close to a new battery.By the time I have doubts about my car's battery, I may as well change it.