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Sanyo Eneloop rechargeable battery review

technologyEdward KiledjianComment

As a business traveler, I adopted rechargeable batteries 5 years ago and haven’t looked back since. I have tried almost every brand of rechargeable batteries and the 2 I have consistently come back to are the Powerex by Maha Energy and the Sanyo Eneloop.

The Powerex is the heavy duty battery that works great in high drain devices. I use Eneloop for everything else.

The value proposition

The value propositions of the Eneloops are: 

  • Come pre-charged
  • Maintain 70% of their charge after 5 years of storage
  • Can be recharged 1500-1800 times 


I recently bought a brand new pack of these batteries and decided to run some tests and share the results here. 


The newest batteries actually list the “Min” mAh value. The AA in my pack list “Min. 1,900mAh” but rest assured their nominal charge is 2000mAh per Sanyo.

Out of the box, I test 8 AA batteries and they all had between 70-85% of their full 2000mAh charge which means (unlike other rechargeables) you can immediately put them to work. I found that during the next 5 complete recharges, the batteries capacity actually increased slightly reaching closer to the 2190mAh level.


When using Energizer rechargeable batteries, they can typically be recharged 400-600 types before their performance starts to really degrade. My oldest Eneloops are close to 1000 recharges and they are still performing to spec.

Shelf life

I used one of my brand new batteries, did 4 drain/recharge cycles then left it in a drawer for 3 months. I pulled it out and tested its charge rate and it still delivered 92% of its advertised charge. I performed the same test with my 3 year old Eneloop's and during the same period, it retained 87% of its charge.

Most other rechargeable batteries typically fall to 40-50% charge after the 100 day mark.

C and D Adaptors

The latest kit I received came with 2 C and 2 D adaptors. This means I can use the Eneloop AA rechargeable batteries in devices that require C or D. Nice little add-on that makes these batteries even more attractive.


Overall I love and recommend these batteries for low or medium drain devices. They will last longer than other name brand rechargeables, come charged out of the box and you can often find them on special at very attractive prices.

Anytime I see a good deal on these, I tend to pick up a couple more (to make sure I never run out of batteries)



Eneloop charger sold with most kits. This charger can fully charge the AA or AAA batteries in 3.5-4 hours (you'll know its done when the battery LED stops flashing). Batteries must be charged in pairs and always pair similar batteries (AA with AA; AAA with AAA).


The C and D adaptors in my kit.


Inserting the AA into the C adaptor


The AA batteries