Nexcell rechargeable Ni-MH batteries and intelligent charger
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The Nexcell charger kit
has AA batteries, charger, mains and car power supplies, and
adapters for C and D cells too. |
The humble NiCad rechargeable
battery has come a long way over the decades. Ten years ago,
you'd consider yourself lucky to find an AA sized Ni-Cd battery
with a 600 mAh capacity. Nowadays, NiCads offer up to 1000 mAh
and newer better Ni-MH batteries can provide more than double
this capacity.
With a life of 200 - 1000
charge/discharge cycles, and capacity equivalent to
non-rechargeable alkaline cells, NiMH batteries are every bit as
convenient and much more sensible.
This product combines high capacity batteries with the most intelligent
charger we've seen, along with some nice extra features, all at
a low price.
Terminology Explained
The life or capacity of a
battery is typically shown as so many mAh (milli Amp hours).
1000 mAh means that the battery can supply 1000 milliAmps for
one hour (or 500 mA for two hours, etc). The larger this number,
the longer the battery life.
There are three main types
of rechargeable battery. The oldest technology is the Ni-Cd
type, Nickel Cadmium (sometimes also called Nicad). These
batteries have relatively low capacities, but are the least
expensive.
Much better are the Ni-MH
batteries, Nickel Metal Hydride. These batteries have about
twice the capacity of the Nicad batteries, but are also up to
twice as expensive.
The third type is a
different technology - Li-Ion, Lithium Ion. These batteries have
much higher capacity than even Ni-MH batteries, but are much
more expensive and are not yet readily available as traditional
rechargeable batteries. They are widely used in better cell
phones, digital cameras, and other such devices, however,
because of their long life and small size.
Nicad and Ni-MH batteries
are each 1.2 volts, whereas normal non-rechargeable batteries
are 1.5 volts. If you are replacing normal batteries with
rechargeable batteries, you need to be sure that the lower
voltage of the rechargeable batteries does not affect the
operation of the device.
If you're using rechargeable
batteries in a flashlight, you might want to get a lower voltage
bulb. If you are using them in a two-way radio, your range might
decrease slightly.
What You Get
The Nexcell Power Station
has everything you'll need :
-
Four very high capacity Ni-MH
batteries (2100 mAh)
-
Plastic carry case to
carry/store the batteries
-
Intelligent
charger/discharger that can charge 2 or 4 AAA or AA
batteries simultaneously
-
110V power supply
-
Car power supply
-
Two C cell adapters to enable
the AA batteries to be used in devices that need C cell
batteries
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Two D cell adapters to enable
the AA batteries to be used in devices that need D cell
batteries
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Instruction sheet
When purchased from
Pro Travel Gear, it has a 30 day money back guarantee and a
one year warranty, and lists for $39.95 (remember to get a 5%
discount by using the 'travelinsider' discount code on their
site).
Description - Charger
The charger is correctly
described as 'intelligent'. Simple chargers are typically no
more than a power source that just feeds power to the batteries,
without stopping. These types of chargers can overcharge and
damage your batteries.
The Nexcell charger uses
four different tests to determine the level of charge in the
batteries, and carefully ensures that batteries don't get
overcharged. It monitors the voltage in the batteries while
they're being charged, it monitors the temperature of the
batteries (when they start to get fully charged, they start to
heat up more), it has a safety test for maximum temperature, and
it also simply has a time logic circuit that also prevents
overcharging.
The charger can charge two
pairs of batteries simultaneously. The right hand pair of
batteries can also be discharged before charging to eliminate
any residual 'memory effect' by pressing the right hand button
after the batteries are inserted.
Once the batteries have been
fully charged, the charger then switches itself to a very low
current that continues to 'trickle charge' the batteries until
you remove them.
Triple color LEDs tell you
what the charger is doing - whether it is discharging batteries,
charging them, trickle charging them, or finished.
A red LED means rapid
charging, a green LED means charging completed. A Green
and red flashing LED means trickle charging, and flashing yellow
means the battery is being discharged and conditioned.
You know when the batteries
have been fully charged, because not only does the charger's LED
change color, but it also starts to play a simple musical tune!
The charger is cleverly
designed so it is impossible to put batteries in the wrong way.
You have both a regular
'brick' power supply that plugs into the regular mains power and
also a cigarette lighter adapter that will take power from a car
or other similar source.
It takes about 4 - 5 hours
to fully charge the batteries in the charger.
Description - Batteries and
Adapters
The four AA batteries have a
very high 2100 mAh capacity. In comparison, a regular alkaline
battery typically provides between 1500 (in high current usage)
and 2500 mAh (in low current usage) of capacity.
The batteries are considered
good for at least 200 cycles (of full charge and then full
discharge). After 200 cycles, they will only be holding 80% of
their previous capacity when showing as fully charged (but this
is still a lot!), so they don't simply stop working after this
stated life capacity.
Now for a secret tip from
one of the Nexcell engineers. He says that if you only charge
the batteries to about 80% of full charge, you'll be able to get
500 to 1000 cycles from them. Apparently all the 'wear' on a
battery occurs as it transitions from nearly fully charged to
completely charged, and so if you only charge to 80% of
capacity, you'll get much longer life.
Use this information two
ways.
Firstly, this is how you can
charge your batteries to only 80% (if you choose to do this - it
is a bit of a bother). Use the charger to completely discharge
your batteries, and then time how long it takes from the start
of charging them until the music starts to play. Work out how
long 80% of this time is, and then use a timer to remind you to
turn off the charger, when charging discharged batteries in the
future, at this time point.
Secondly, remember that all
batteries 'wear out' most during the final part of their
recharging. So never fully charge or over charge any batteries,
anywhere. It doesn't matter if you exactly charge to only 80%,
or to 60%, or to 95%, but try and keep it down below 100%, and
certainly don't go over.
The complete Nexcell Kit
also has two C cell adapters and two D cell adapters. These are
very clever. Simply slide the AA batteries into these hollow
adapters and then they will fit into things that need C and D
cells. Of course you won't get as much life out of the AA
batteries as you would out of C or D batteries, but for things
you rarely use, it saves you having to buy additional stocks of
other sized batteries.
Other Issues
Nicad batteries have a
'memory' effect. What this means is that if you only half
discharge them before recharging them, they mistakenly think
that the half discharged point where they started to be
recharged again is actually the end of their life, and next time
give you much less capacity. For this reason, if you find
yourself using Nicad batteries, be sure to completely discharge
them (eg by using the discharge feature on the charger) before
recharging them.
Ni-MH batteries don't have
quite the same memory effect, but they still have some degree of
memory effect. It is a good idea to completely discharge them
perhaps once every five or ten charging cycles, so as to keep
them at maximum capacity.
This charger takes four to
five hours to charge the batteries. There are other chargers
available that are much faster in operation, but these faster
chargers can sometimes harm the batteries due to their higher
speed. The thing that shortens your battery life the most is
heat buildup inside them - and the faster a battery is charged,
the more heat it gives off and at a faster rate. It is better to
accept a 4 - 5 hour gentle charging rate, and enjoy longer
battery life as a result, than it is to buy a 'fast charger'
that runs the risk of not only quickly charging your batteries
but also of quickly ruining them!
Update July 2004
Since this review was
written in December 2003, technology has continued to move
forward. In December, a 2100 mAh battery was 'state of the
art'. Today - as you can probably see from the Google ads
on this page - it is possible to find 2400 mAh batteries.
Tomorrow - probably even higher capacity batteries.
This does make the Nexcell
product of 7+ months ago no longer as outstanding as it was,
then. The charger technology remains excellent, however.
Use the information in this
review to help you evaluate batteries and chargers, even if you
no longer choose to buy the actual Nexcell product that was
reviewed back in December. You can visit the
Nexcell
website to see their current product range.
Summary and Recommendation
This complete kit is priced
at $39.95. This makes it very competitively priced, compared to
other products available. Additional packs of four batteries are
$14.40.
Although one of the lowest
priced complete kits, it is also one of the best. Recommended
without reservation accordingly.
It is sold through
Pro Travel Gear (the same people that created the wonderful
Plane Quiet headphones), and if you
enter the code 'travelinsider' (without the quotes) into their
coupon box, you'll get a 5% discount.
Rechargeable batteries can
save you a great deal of money over their 200-1000 cycles.
There's no reason not to invest in one of these units.
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Originally published
5 Dec 2003, last update
21 Jul 2020
You may freely reproduce or distribute this article for noncommercial purposes as long as you give credit to me as original writer.
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