Battery Tester!!

[TennDave]

I wanted something to do quick and dirty battery testing- coming off the charger and also as they appear to be spent. I ordered this one from eBay and it came today (cheap enough- about $4 shipped from China...so it takes awhile):

Problems is that it's not accurate at all. Also, the top portion is set too far in- I had to use a piece of tin foil for it to make contact w/ my AW 14500. Anyway, at full capacity (4.2V), this thing reads somewhere between 5.57 and 6.2V...not good. I tried it on a regular AAA battery and same thing- it's off compared to my volt meter by up to half a volt- and that's not good considering those are at 1.5V

I really do want something simple (besides actually putting 2 wire probes on the positive and negative end of the batteries (I know there are those that screw into the atty connector that work like this but don't want to unscrew attys every time I change batteries on my mini)...someone's bound to sell a cheap/practical option. I'm hoping that this other one on eBay will actually work and be more accurate (a bit more but still affordable- $7 or so, shipping included:

 

[TennDave]

I wrote the seller...I really didn't want to leave him negative feedback without some type of contact, but the deal is on the buyer to send it back...hmmm, to Hong Kong. Total cost was $4 and sending it back will cost more, so I know I won't.

 

[RocketRod]

Dave are you talking about the top picture? Could be a first run off a production line that was flawed or didn't meet QA, like they were for some other use but were adapted for the tester you got. Something as inexpensive as that wouldn't warrant even a look see in the company i work at. $4 is about 1 minute of an engineers time where i'm at, and they probably have less than a buck in it. Glad your looking for ways to help us tho!

 

[TennDave]

Thanks RocketRod- yeah, I figured as much. I would pay a bunch more for something simple but digital you know...wish one stretched out enough to test an 18650 too but I figured if I got one that works for fairly cheap, I could sort of "modify" it to do that job too. Of course it won't test ohms, but I even thought of a "well" cut into one of these "testers" where you screw your atty down into to read ohms. Someone needs to make something small, fits into your pocket that does all of that. Multimeters are nice but I was thinking of something smaller/simpler and something that doesn't have wires and probes.

 

[byronchurch]

Amen I'm looking to!

 

[Sterno]

Dave i use this battery meter with a wire connected to it and its pretty accurate

Battery Voltage Indicator

 

[TennDave]

Dave i use this battery meter with a wire connected to it and its pretty accurate

Battery Voltage Indicator

STerno, with wires in a different location, will it test ohms?

 

[Sterno]

STerno, with wires in a different location, will it test ohms?

i dont think so

 

[TennDave]

Okay, thanks- I have one that screws in the well that works for testing the batteries all hooked up- seems best for me right now. I got the blue one mentioned above- wasn't accurate, so I wrote the seller...took forever but I got a replacement, but it was the same thing- really inaccurate, even on 1.5V batteries and 9V squares... I didn't have the heart to give the seller a bad rating- he really did try...he's just selling an inferior product. Oh well.

 

[Big Hitter]

Hi Dave, I bought a second set of leads for my multi-meter (around 3 bucks) cut them at 12 inches and soldered the cut end to an old charger I had. Its a cheap spring slidey one that goes from 30mm to 70mm. So I just leave the unit plugged into my MM next to my charging station. All I have to do is turn the meter on and slip the batt into the unit to test.

I'll take a pic and post it when I'm upstairs later.

 

[byronchurch]

how do you interpret these little vu meters i can't see the difference between a 1/2 and a full charged battery

 

[TennDave]

Sounds great- would love to see that!

Hi Dave, I bought a second set of leads for my multi-meter (around 3 bucks) cut them at 12 inches and soldered the cut end to an old charger I had. Its a cheap spring slidey one that goes from 30mm to 70mm. So I just leave the unit plugged into my MM next to my charging station. All I have to do is turn the meter on and slip the batt into the unit to test.

I'll take a pic and post it when I'm upstairs later.

Sent from my DROID3

 

[steved5600]

Dave i use this battery meter with a wire connected to it and its pretty accurate

Battery Voltage Indicator

For sealed battery assemblies you need True RMS. Found out mine use a Pulsed DC which is a Square wave. a regular DC voltmeter will not give an accurate reading on them but will work good on just the battery .

But I love this. am in the middle of building a atty and battery tester.

 

[TennDave]

Yeah, let us know how the atty and battery tester combo works out!!
That was my intention too...MadVapes sells the guts for the atty tester and I was going to combine it with my battery tester, but in trying to build it, I melted a spring for the internal batteries, so I did not do a good job of putting the atty tester together.
Anyway, if you want to see my battery tester, it's in the subforum here somewhere- Sterno dubbed my tester the Doohickey or something along those lines.