Re: Extech EX410A DVM Don't Buy

On a sunny day (Sat, 05 Oct 2024 06:35:12 -0700) it happened Jeff Liebermann
<jeffl@cruzio.com> wrote in <bdd2gj50jheq0r2uv7c9qfvidc12bg91g4@4ax.com>:

On Sat, 05 Oct 2024 06:45:27 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
>

On a sunny day (Fri, 04 Oct 2024 16:07:24 -0700) it happened Jeff Liebermann
<jeffl@cruzio.com> wrote in <7so0gjtispsfqvv9klhq9vlsgfpqd1vs2m@4ax.com>:
>

On Thu, 03 Oct 2024 14:46:46 -0700, john larkin <jl@glen--canyon.com>
wrote:
>

Extech EX410A  DVM  Don't Buy
>
The auto power off is incredibly stupid. I'm going to throw mine away
and get something usable.

>
What don't you like about the auto power off feature in the EX410A?
>
EX410:
<https://www.flir.com/products/ex410a/>
>
I have two Extech EX470 DMM's:
<https://www.flir.com/products/ex470a>
Presumably, the auto power off function is similar.
>
I've had both DMM's for over 10 years and use them often.  I've had no
difficulties except with various 9V batteries.  I got tired of
replacing them.  Over the last 5 or so years, I've experimented with
two types of rechargeable Li-Ion 9V batteries. 
>
The ones without an internal battery charger had self-discharge
problems:
<https://www.ebay.com/itm/304501384792>
They work, but I wouldn't recommend them.
>
The batteries I'm using now, which have a built in charger, are
better:
<https://www.ebay.com/itm/386563315011>

>
Interesting, did not know that existed.

>
Eventually, there will be batteries and cells available in every
combination of size and chemistry.  Whether all combinations are
usable, practical or economical, is a different problem.  I didn't
know Li-Ion AAA cells existed until after I searched for them.  One
day, they magically appeared on eBay and Amazon.
>
Incidentally, you might find these web pages of interest:
"Low current discharge of batteries"
<https://lygte-info.dk/info/BatteriesLowCurrentDischarge%20UK.html#9V,_Panasonic_Pro_Power>
<https://lygte-info.dk/info/BatteriesLowCurrentDischarge2%20UK.html>
Most of the battery related forums emphasize high current
applications, such as EV's, power tools, drones, flashlights, LED
lighting, etc, while low current devices, such as multimeters,
component testers, ESR meters, TDR's, etc seem to be neglected. 
>
I think LiFePO4 (lithium iron phosphate) is a better solution for test
equipment and TV remote controls.  With a nominal 3.2V voltage, a
single AA or AAA cell should substitute well for the usual two AA or
AAA cells in series arrangement:
<https://www.ebay.com/itm/387366292333>
I'm trying to resist ordering some cells and creating yet another
project that I can't finish.
>

OTOH my multimeter lasts years on a 9V battery from the supermarket here..
meter switches off automatically, but I switch it of by hand almost always.
means it is never left on for more than 24 hours..
https://panteltje.nl/pub/chinese_multimeter_img_3159.jpg

>
My main goal is to eliminate non-rechargeable batteries from my life,
especially alkaline cells, which tend to leak and corrode terminals,
wires and PCB's:
<https://www.learnbydestroying.com/jeffl/crud/Kirkland-AAA-leak.jpg>
>

I use this too sometimes:
https://www.conrad.nl/nl/p/voltcraft-vc-320-stroomtang-digitaal-cat-ii-600-v-cat-iii-300-v-weergave-counts-2000-1307543.html
>
Have a Voltcraft soldering station too, now for > 20 years, is OK.
https://panteltje.nl/pub/soldering_iron_LCD_display_IMG_5456.JPG
never a problem...

>
I have a box full of Weller WTCP series (TC202 base) very used
soldering stations along with a collection of half burned out tips.
<https://www.google.com/search?q=weller+wtcpt&udm=2>
I repaired what I could and produced about 15 working soldering
stations from the parts.  I sold most of these, but still have and use
about 4 of them.  I've had them since early college, which makes them
about 55 years old. 

I remember the Wellers from work, had one for years at home too.
As to rechargable AAA and AA I use 'Eneloop' batteries,
self discharge is almost zero, nice in a small flashlight (always light even if not used in ages)
in TV remotes, even in my gamma spectrometer.

I have some AA lifepo4 and a 250 Ah big 12V lifepo4 pack with a 2 kW 50 Hz DC/ AC converter
that can power my fridge or even a cooking plate or a microwave if needed.
 https://panteltje.online/pub/250_Ah_12V_to_230V_sinewave_IXXIMG_0796.JPG
Flexible solar cells I can lay out in the garden... and a charger for the battery pack.
I do use a lipo in my weather station, one 3V lipo + a short (Ohm) AAA battery
to replace 2 1.5 V batteries, same in one remote.
The weather station runs a few month on that before it needs a re-charge.
The remote I do not remember having recharged in a few years...
And have several lipo 2 and 3 cell models for my drones:
 https://panteltje.nl/pub/3cell_40C_ebay_lipo_IMG_6682.JPG

And ofcourse many of these in different projects:
 https://panteltje.nl/pub/SWR_bridge_wired_IMG_5013.JPG
 https://panteltje.online/pub/SWR_bridge_on_dummy_load_IMG_5046.JPG

As a kid I started with 4.5 V batteries...