This article was first published in late 2017 and subsequently lost in the website crash. I was unable to retrieve it, I had to rebuild it from my notes and scattered bits and pieces. This article is the result.

Comparison/Evaluation of Rechargeable AA Batteries – Eneloop vs. Tenergy

Panasonic BK-3MCCA4BA Eneloop AA

• Ni-MH (Nickel Metal Hydride)
• 2000mAh
• 2100 cycles
• $2.46 (Amazon 4/3/20)

Tenergy Premium AA

• Ni-MH (Nickel Metal Hydride)
• 2500mAh
• 1000 cycles
• $1.25 (Amazon 4/3/20)

Basic Comparison from product specs and after opening the package:·

• Eneloop claims more recharging cycles (2100 cycles vs. 1000 cycles)
• Tenergy claims 25% more storage capacity (2500mAh vs. 2000mAh)
• Enloop shows more out of the package charge (1.38v vs. 1.35v)

Charging:

I used the same smart charger for both brands. Same charging cycle at the same time. Alternated the batteries in the charger trays. Used “refresh” cycle to drain and charge the batteries equally. Allowed to sit 1-hour after charging cycle before testing:

• Eneloop 1.38v
• Tenergy 1.35v

Discharge:

I put them into brand new AA battery flashlights purchased at the same time, same brand & model. Turned em on and let them run. More than 48-hours later the results were startlingly significant.

• • The flashlight with the Eneloop batteries couldn’t keep the light on.
  • The flashlight with the Tenergy batteries was still very bright.

I was surprised to say the least…in practical testing the Tenergy blew away the Eneloop. But, I wanted to see how much more energy the Tenergy battery had left. I put the voltmeter to each battery:

• • The Tenergy batteries had 1.197v left (average).
  • The Eneloop batteries had .869v remaining (average).

Performance wise…the Tenergy batteries absolutely blew away the Eneloop batteries! It was even close! Not only did the Tenergy batteries have over 35% more energy left in them, the Eneloop couldn’t even keep the light on.

Overall conclusion…Tenergy is by far clearly the better priced battery and better performing battery.