5 ms·

Very reliable for telling brand new vs 100% depleted batteries. But if you want to separate 1.4 volt batteries from 1.5 volt batteries, use a multimeter.

xen2xen1 3y ago
Or the $1.50 tester from Ebay.
- horsawlarway 3y ago
  Yes - but why when you can get a multimeter for $10 (incl shipping)? So much more useful for so little extra money (since those $1.49 battery testers on ebay cost $2.50 to ship anyways, and they take 20 days to show up).
  - tuatoru 3y ago
    A multimeter doesn't put any load on the battery. A (decent) tester will have an appropriate load for the type of battery of about 0.05 to 0.1C, so for a 2200 mAh AA NiMH, about 110 mA to 200 mA. 10 - 12 ohm resistor for 1.2V nominal. This shows you the cell's internal resistance, an increase of which is a sign of impending doom for a battery. If you use your batteries at high currents, test at those currents.
    - horsawlarway 3y ago
      Sure - but a multimeter also doesn't require the battery to be inserted into it - you can test the voltage while the battery is under load in most devices. Not saying you can't buy a really good dedicated battery tester if that's what you want - but that dolla-fiddy version from ebay ain't gonna be it :)
  - xen2xen1 3y ago
    Because it's much simpler to have a 1.50 tester sitting with the batteries that's fixed function than dealing with the leads, the proper setting, finding the right band of numbers if it's analog. There's something to be said for fixed function.
silisili 3y ago
It's a little more granular than that. At minimum, you can tell full from half full from mostly empty. But yeah, not 80% vs 70% or anything like that.
nuancebydefault 3y ago
I found that the voltage does not say much, at least not for a general type. Just put your multimeter in 20 A mode and make sure you connect the red cable to A terminal. Use it to shortly short circuit the batt. A good (charged) battery delivers >8A

xen2xen1 3y ago

Or the $1.50 tester from Ebay.

horsawlarway 3y ago
Yes - but why when you can get a multimeter for $10 (incl shipping)? So much more useful for so little extra money (since those $1.49 battery testers on ebay cost $2.50 to ship anyways, and they take 20 days to show up).
- tuatoru 3y ago
  A multimeter doesn't put any load on the battery. A (decent) tester will have an appropriate load for the type of battery of about 0.05 to 0.1C, so for a 2200 mAh AA NiMH, about 110 mA to 200 mA. 10 - 12 ohm resistor for 1.2V nominal. This shows you the cell's internal resistance, an increase of which is a sign of impending doom for a battery. If you use your batteries at high currents, test at those currents.
  - horsawlarway 3y ago
    Sure - but a multimeter also doesn't require the battery to be inserted into it - you can test the voltage while the battery is under load in most devices. Not saying you can't buy a really good dedicated battery tester if that's what you want - but that dolla-fiddy version from ebay ain't gonna be it :)
- xen2xen1 3y ago
  Because it's much simpler to have a 1.50 tester sitting with the batteries that's fixed function than dealing with the leads, the proper setting, finding the right band of numbers if it's analog. There's something to be said for fixed function.

silisili 3y ago

It's a little more granular than that. At minimum, you can tell full from half full from mostly empty. But yeah, not 80% vs 70% or anything like that.

nuancebydefault 3y ago

I found that the voltage does not say much, at least not for a general type. Just put your multimeter in 20 A mode and make sure you connect the red cable to A terminal. Use it to shortly short circuit the batt. A good (charged) battery delivers >8A