Battery tester

[T1 Terry]

There was thread a while back on the Grey Nomad forum about battery testers https://thegreynomads.activeboard.com/t ... with-this/ and today I received an email from Kogan offering what looked to be the same item but a tad more expensive and no free post. A bit more looking on evil bay came up with these https://www.ebay.com.au/itm/12V-Digital ... 0005.m1851 $41 or $38 if I bought 4 at the same time and free postage.
Anyone had anything to do with these things? Had a lot on enquiries about testing their AGM batteries at Stone the Crows this yr so I'm thinking of buying at least one of them

T1 Terry

[Greynomad]

What happened to the old 'screwdriver-across-the-terminals' test?

[T1 Terry]

What happened to the old 'screwdriver-across-the-terminals' test?

Rather exciting across a lithium battery. Tends to damage the lead terminals on a lead acid battery and the escaping hydrogen and oxygen tends to go bang when you make the arc getting the screw driver back off the terminal, not to mention the damage to the screw driver itself

[bagmaker]

how does it test a load???

[T1 Terry]

No idea, it doesn't seem to be a load tester as such but more a unit that looks at internal resistance and voltages and uses the Ah capacity to determine what a good battery internal resistance should be and somehow determines remaining capacity from there.

T1 Terry

[Peter and Sandra]

I've had one for few years and have used it quite a bit, mainly on the mates farm where everything has its own battery from quad bikes to electric fence units, tractor, bulldozer, excavator etc. much of the gear sits for long periods without use and while some things have a small solar panel to keep the batteries up they do eventually die.
Usually when something won't start I get a call "bring your battery tester over" and I always test with a multimeter first.
The one I've got was a ebay cheapie and compared to the local tyre/battery suppliers when we compared it with his that cost about fifty times more than mine but does give a thermal paper printout the readings were pretty much identical when we tested about half a dozen batteries from brand new to buggered.
https://www.ebay.com.au/itm/Digital-12V ... SwjMdbX~BA
It does seem to do a load test as you enter the CCA in initially and it gives a measurement, internal resistance and a bar graph from bad to good as to battery state.
I've found if it says the battery is no good that it is usually the case and even putting the battery on an old transformer type charger for a day or so doesn't bring them back.

[T1 Terry]

Thank you Peter, looks like I'll get at least 1 of these. I wonder if there would be a market to sell 3 of them at the next STC so I get mine cheaper

T1 Terry

[Craig]

I don't like these. I have used them in the past and what I have found is if they indicate the battery is stuffed then it is BUT if if indicates it is good it does not mean it is. I had two batteries that indicated good but both were not and luckily were replaced under warranty after I insisted they test them with a carbon pile tester.

[supersparky]

These things do work, but only really in comparing multiple batteries of the same type. They are really made for testing UPS systems where you might have up to 20 x 12v batts connected in series. It will indicate which one is crook without isolating or disconnecting they load.
I still reckon the 20 hour test is the best for AGM's or similar. Haven't got Lithiums yet so still don't know enough to comment. I would leave that up to T1

[T1 Terry]

We plan to do a video test of a 100Ah AGM and a 100Ah Winston lithium battery that we build, both tested at the C20 rate. If that goes well we will then do a similar test with 2 x 100Ah AGM batteries at the C20 test rate (10 amps) and the 100Ah lithium battery at the 10 amp load rate or a C10 test rate, just to see if 100Ah of lithium really can do what 200Ah of AGM's can.
It all started from a post on the Grey Nomad forum by Peter'n'Margaret Peter with the OKA with a goanna painted on the side https://thegreynomads.activeboard.com/t ... t-65714397 where he says an Ah is an Ah no matter what the chemistry and 200Ah of lithium could not replace 400Ah of AGM batteries.

T1 Terry