The recommended maximum charge rate from most battery manufacturers is 1C, or 1 x the Capacity of the battery. For a 2700mAh AA battery, the maximum charge rate is 2700mA. A 15 minute rapid charger is very aggressive, charging at 4C. Absorbing the energy so fast will cause the batteries to become quite hot, and will shorten the life of the batteries. Any charger that takes 1 hour or longer to charge batteries will meet the 1C recommendations.

For example, The MH-C801D has a standard charge rate of 2000mA for AA batteries, so it is below the maximum recommended charge rate for our 2100mAh IMEDION AA batteries and our 2700mAh Powerex AA’s. The MH-C801D also has a SOFT CHARGE feature, which halves the charge rate to 1000mA, making the charging process even easier on the batteries. I would recommend using the SOFT charge feature whenever you have the time to charge your batteries at 1000mA, and feel free to use the 2000mA charge rate when you need batteries charged fast.

The ten types of batteries tested were as follows:

Sanyo eneloop “Pre-Charged” – 2000mAh, MAHA Powerex – 2700mAh, MAHA Powerex Imedion “Pre-Charged” – 2100mAh, Rayovac Hybrid “Pre-Charged” – 2000mAh, Rayovac “15-Minute” Rechargeable – 2000mAh, Duracell DX1500 Rechargeable “Pre-Charged” – 2000mAh, Kodak Rechargeable “Pre-Charged” – 2100mAh, Energizer Rechargeable – 2500mAh, La Crosse Rechargeable – 2600mAh, Energizer Max Alkaline – “Use by 2013”

Given that this test was conducted in the USA, some of the tested brands are not available in Australia, however, the significant results are that the Powerex 2700 AA rechargeable batteries provide the faster refresh time than any of the other batteries, and the IMEDION provided the fastest flash refresh time among all the Low discharge (ready to use) AA batteries.

Another significant result is that the Powerex IMEDION AA batteries provided more flash pops that all the other brands of low self discharge (ready to use) AA batteries.

You can read the (extensive) test results and procedures at the Photography on the net forum

Now here’s the longer answer: Not all chargers are created equal

My first battery charger was an Energizer. The above image shows part of the back label. This is a timer charger. Timer chargers simply provide charge to the batteries for a certain amount of time, in this case: 15 hours. They provides the same amount charge to all batteries, irrespective of capacity. Thus their suggestion to remove (lower capacity) NiCD batteries after 5-6 hours. This type of charger will overfill lower capacity batteries, and probably not fill a 2700mAh AA battery, resulting in less performance on both counts. This is affectionately called a “dumb” charger.

You will always get better results in a charger which measures the voltage of the batteries as it charges, and stops charging when the battery is full. This ensures a full charge without overcharging, ensuring maximum battery performance, and maximum life for the battery. Smart huh? This is why they are called “smart chargers”.

Another type of charger is fifteen minute “rapid chargers”. They are hard on batteries, and will not competely fill the battery as much as a 60 to 100 minute charger. Charging batteries in 15 minutes also causes the batteries to heat up a lot and reduces the life of the battery.You will get a fuller charge and longer life from your batteries if you choose a charger that takes 60 to 100 minutes to recharge the cells.

Another way that a good charger extends the life of batteries is by offering a “soft charge” option. Some chargers have a 12 hour charge option, but unlike the “timer chargers” we have talked about, they utilise measurement of the change in voltage to prevent under charging or over charging the batteries. If you don’t need the batteries charged straight away, choose to use the soft charge option on your charger.
A slower charge will heat the batteries less, and provide even more life for your batteries.

NiMH batteries lose 1-3% charge each day when not being used. For maximum performance, use a charger with a maintenance charge to keep them topped up. Some chargers have a trickle charge option. A constant trickle will keep them full, but is more charge than they need. A maintenece charge will give them just enough to keep them full.

Maha chargers address all these factors, and thus provide the highest performance for your NiMH and NiCD batteries.

How many batteries can I charge at the same time?

You can charge up to Ten 9V batteries at the same time in the Maha MH-C1090F 9V fast charger.

Do I have to charge 10 batteries at a time?

No. The MH-C1090F has ten individual charger circuits, so you can charge any combination of 1 to ten batteries.

How will I know when the batteries are charged?

When the batteries are fully charged, the LED beside the battery will change frm red to green. Each battery is charged individually, so it will be cahrged to it’s full potential.

Do I have to take the batteries out once they are charged?

No, when the batteries are charged, the 1090F charger will measure the slight negative change in voltage and know that the battery is at full capacity. It will then switch to a trickle charge to keep the batteries at full capacity until they are needed.

We tried using rechargeable batteries in our microphone but they went flat in the middle of a performance. How do we avoid this from happening?

Todays rechargeables have much higher capacities than even 2 years ago. Our customers are getting 3 to 5 hours from their microphones using the Maha 9V batteries and the Maha 490F or 1090F. This is enough for almost any performance! Rather than leave them in the microphone for several performances, take them out after each performance, and put them back in the charger.

Do I need to run the batteries flat to keep them in good condition?

The older NiCad batteries were succeptibe to the memory effect if not empties. NiHM batteries have a different chemistry, and do not require emptying. Also, the Maha charger uses a unique Flex Pulse charging method which conditions and enhances 9V rechargeable batteries as they are charged.

Can I use the MH-C1090F ten bank charger to charge my older batteries?

Yes. The Maha 1090F is compatible with 7.2V, 8.4V, and 9.6V batteries, so long as they are Rapid Charge Capable 9V rechargeable Batteries. It is also capable of capable of reviving older 9V rechargeable batteries which may no longer be accepting a charge.

We use a LOT of batteries. Is this charger suitable for commercial use?

The 1090F is designed for commercial or home applications. Many professional stage compnies use Maha battery chargers and 9V rechargeable batteries. The charger is very well made, and comes with a 3 year replaceent warranty.

A: You can search high and low, but at this point in time, no-one makes Lithium Ion or Lithium Polymer rechargeable AA batteries as a matter of safety.

Lithium rechargeable cells are a completely different technology to NiCd or NiMH batteries. LiIon and LiPo batteries require controlled charging and discharging. Lithium battery cells are usually 3.0, 3.6 or 3.7 volts, which is quite different than the 1.2V cells that make up Nickel based batteries. If lithium cells are charged or discharged improperly, they can and do explode. The potential liability on the manufacturer of the batteries means no-one has been prepared to manufacture and sell rechargeable Lithium AA batteries.

Looking for our motorbike gear? We have set up a separate website for these products. You will find the S3 Performance Equipment motorbike leathers, tie-downs, fenders and other products at S3performance.com.au

An option to extend the battery life of the Nikon D80 is the MB-D80 Battery Pack/Vertical grip as shown in the photos. This will hold two of the Nikon EN-EL3e batteries, or six AA batteries.
The EN-EL3e is the same battery as used in the D200. Note that the EN-EL3 (as used in the D70) cannot be used in the Nikon D80 or D200.

The En-EL3e battery provides 1500 mAh at 7.4 V (11.1 Wh), so a pair would provide 3000mAh at 7.4V.

Maha PowerEx AA batteries are compatible with the Nikon MB-D80. Six of our 2700mAh AA batteries would provide 2700mAH at 7.2V, and thus provide a nearly the same amount of battery power, but cost substantially less than one EN-EL3e battery.

It is reported that a single D80 battery will provide 2,700 shots, so the battery pack with 6x 2700mAh AA batteries should provide the camera with enough power to take around 4,860 photos off a single set of batteries, whether they are EN-EL3e or rechargeable AA’s.

Charging a set of four 2500mAh batteries with a Maha PowerEx 401FS charger (on soft charge at 300mA charge rate) should take about 9 hours. 300mA at 12V is 3.6 watts of power. To charge for 9 hours at 3.6 watts, that’s 32.4 watthours. At a price of fifteen cents per kilowatt hour, the cost is 32.4/1000 x 15 cents, or 0.48 cents to charge the batteries. Even if the efficiency of the chager was only 50%, the cost would be 0.96 cents to charge the four batteries.

So if you recharge your batteies once every week, the cost is 0.96 cents x 52 weeks, or 50 cents for the whole year.

That’s low cost battery power!

Shown above is my Maha MH-801D charging some old Energizer 2500mAh AA and Powertech 800mAh AAA batteries.

Battery technologies have come a long way in just a few years, and continue to improve. A few years ago, the highest capacity AA battery was a 1800mAh NiMH. Before that they were 600mAh NiCD’s. Today we have 2700mAh NiMH AA’s, and tomorrow, who knows?

If you have some old rechargeable batteries you still want to use, then be aware that their ability to take charge from a rapid charger is limited, be it a Maha charger or any other brand. As a rule, AA batteries over 2000mAh and AAA batteries over 700mAh are fine in Maha rapid chargers. To recharge older cells, you are best to choose a charger with a slow option, such as the 5 hour charge of a MH-C401FS or the MH-C801D and not the MH-C204W travel charger.

Low discharge batteries such as Sanyo Eneloop and Powerex Imedions are also 100% compatible with Maha Powerex chargers.