AA NiMh battery test results

[torchythebatteryboy]

I had a lot of requests for test results of D size batteries at currents up to 5A. Is there any demand for higher current from AA NiMh batteries? Test results at 250mA can be found here: Torchy the Battery Boy: NiMh AA batteries

[ChibiM]

Uhmm 300mAh?

[torchythebatteryboy]

Not one of the best.

[torchythebatteryboy]

@PeterRamish

Torchy,

I thought I would ask, do you do any run time calibrated lab based discharge tests on your battery? The reason I ask is that is what I rely on to determine if I have a matched set of cells in a pack that will be running, for example, a Thorfire TK4A in normal EDC use… The drill goes like this:

1.) Examine all 4 proposed batteries from matching serial numbers, for example BK-3MCCA.
2.) Pull up chart showing calibrated lab tests for that battery on HKJ site (or yours?) and find the 1 amp draw down time in minutes.
3.) Full charge the batteries in the set on a good charger (I use a Powerex) to same voltage
4.) Rest the batteries for 12 hrs then put each one in turn on a DIY draw down tester
5.) Note the time in minutes that each one takes to draw down to a handy voltage, say for example 1.0V and see if that number of minutes that is returned by this field testing agrees with the numbers from HKJ or other calibrated lab test.
6.) If all batteries in the set are identical, then they are good to go. Re- charge them and install in your TK4A and perform a run time test, on for example, Medium Mode, or some mode that does not do “driver step down”.

There has been a lot of confusion on the “review” section of BLF about batteries, light run time tests, and how the batteries influence the normal use of EDC lights. Batteries are tightly engineered into the driver and LED system on modern lights, and our “review and testing” must pay attention.

Here is an example chart from HKJ and also a pic of my DIY draw down tester. I might add that I do not trust micro processor controlled so-called “analyzer chargers”. Old style low tech resistance testers are known to be a better way to test in relation to real world use of your EDC light. A micro processor controlled tester, the specifics of its programming, which are undocumented and unknown to you (the test engineer!) are next to useless.

Note the ’blue line” showning 110 minutes at 1 amp. This is what we will be field testing for…

No. The main aim of these tests is to weed out the dross like the BTY “3000mAh” which is actually nearer 300mAh from the decent quality batteries.