Sunday, 3 May 2015

Japanese and Chinese Eneloop: a big difference... for extreme users

[Mark] from ultrasmartcharger.com made an interesting comparison: he compared how Chinese and Japanese Eneloop batteries age and the difference was HUGE!

It seems that after 750 cycles (that's more that two year if you charge it every single day) the Chinese version of Eneloop starts to lose capacity while the Japanese keeps its capacity very well.

This might not be a game changer for most of us... But will be for professionals charging their batteries more than once a day.

I recommend reading [Mark]'s full post as it is really interesting (and technical).
I'm however a little disappointed to see that there is no way to know where your Eneloops were manufactured before purchasing them.

Monday, 10 March 2014

The Carrefour Alkaline: very good disposable battery

Manufacturer Carrefour
Format
AA
Model Alkaline
Chemistry
Alkaline
Compare Alkaline batteries
Purchase place Carrefour
Buy online
n/a
Observations
This battery is very good. It has a very decent battery cost, value and internal resistance which makes a good all purpose disposable battery. Better performing batteries exist but come at much higher price tag (and therefore a worse value).
Tested batteries
Number of discharges
1
Testing period
09/03/2014 - 09/03/2014
Battery cost
Internal resistance
Cost of one battery. Since all batteries are not made equal, price alone will not give much info about the value
A battery with a lower internal resistance will perform better in high drain devices (e.g. camera flashes)
0.75 €/battery
124 mOhm
Battery capacity
Energy cost
A higher value indicates the battery containts more energy
This indicates how much you pay for the energy inside your battery (value for money)
1,887 mAh
2,206 mWh
0.40 €/Ah
0.34 €/Wh

Legend

   Among the best performing batteries
   Well performing
   Weak
   Among the worst

Thursday, 27 February 2014

Easy alkaline battery test: no tool needed

You have no meter and want to find which of your Alkaline batteries are fresh. Just use this brilliant test and find out:

 

This test only works with Alkaline batteries as it relies on their chemistries. As they discharge, the chemical reaction inside releases some gas (which makes them bounce). This test however comes with its limitations: while fresh batteries don't bounce, bouncing ones might still have significant juice inside.

Monday, 17 February 2014

TopCraft Ultra Alkaline from Aldi: unbeatable value but limited capacity

Battery information

Test results

Manufacturer
TopCraft
Cost per battery
0.25 €
Model
Ultra Alkaline
Format
AA
Energy cost
Chemistry
Alkaline
Compare Alkaline batteries
Cost per Ah
0.17 €
Origin (e.g. store)
Aldi
Cost per Wh
0.14 €
Buy online
n/a
Performance
Capacity (mAh)
1,460 mAh
Capacity (mWh)
1,759 mWh
Internal resistance
210 mOhm
Self discharge
?

Our conclusions

  • Limited capacity
    This battery has much less capacity than any other disposable alkaline battery I tested so far. It has a third less than the Duracell Ultra Power (but is so much cheaper).
  • Lowest cost
    This is the cheapest battery I have found so far. The battery is so cheap, no matter how little energy it delivers, it will always be cheaper than other disposable alkaline batteries.
Bottom line:

Sunday, 16 February 2014

If I had to buy NiMh batteries and a charger today...

The gear I'm listing below is what I would personally purchase today if I had to buy AA/AAA NiMh batteries as well as NiMh charger.

The charger

Tensai TS 2800
If you want to keep your batteries for a long time, say away from the average charger that can be found in hardware stores. These usually charge batteries two by two and can lead to overcharging your batteries if your batteries do not hold the same charge or capacity... which is virtually always the case even with batteries from the same model/brand. You can read more about this subject here.

Although I have only tested tested its big brother (the Tensai TI-1600L), the Tensai TS2800 (costs about 20€) and can charge batteries individually (using the delta V technique) and also has a discharge function. It is really easy to use and comes with an USB port (that could be handy if you travel with it).

Sencys - Pile rechargeable: a good deal for a hardware store

Battery information

Test results

Manufacturer
Sencys
Cost per battery
3.25 €
Model
Pile rechargeable
Format
AA
Energy cost
Chemistry
NiMh
Compare NiMh batteries
Cost per Ah
1.59 €
Origin (e.g. store)
Brico
Cost per Wh
1.28 €
Buy online
n/a
Performance
Capacity (mAh)
2,044 mAh
Capacity (mWh)
2,529 mWh
Internal resistance
44 mOhm
Self discharge
?
Capcity (mAh, before first charge)
1,491 mAh
Capcity (mWh, before first charge)
1,768 mWh

Our conclusions

These are the best value batteries to be found at Brico (Sencys is apparently only selling through this hardware store chain). Its price is fair and its performance is all right. Much better deals can however be found online (check my NiMh comparison).

Saturday, 15 February 2014

Duracell rechargeable precharged: excellent but expensive

Battery information

Test results

Manufacturer
Duracell
Cost per battery
5.00 €
Model
RECHARGEABLE preCHARGED
Format
AA
Energy cost
Chemistry
NiMh
Compare NiMh batteries
Cost per Ah
2.02 €
Origin (e.g. store)
Brico
Cost per Wh
1.61 €
Buy online
Click here
Performance
Capacity (mAh)
2,475 mAh
Capacity (mWh)
3,100 mWh
Internal resistance
35 mOhm
Self discharge
?
Capcity (mAh, before first charge)
1,065 mAh
Capcity (mWh, before first charge)
1,269 mWh

Our conclusions

These are good NiMh batteries, very good ones. Just look at these performances. If you ask me, they're outrageously expensive in stores but can be found online for a slightly better price.

You can however get better value for your money: check my NiMh comparison.