It has been a long time that I didn't
update my resources page. I received many enquiries and constantly receiving
emails and messages asking about charger compatibility with a certain type of
batteries. I myself have spent quite a fortune buying many different types of
charger, some are good and mostly are just so so...hence I decided to write
something on the charger and batteries mystery (apply to all AA / AAA / D / C
size charger) so that users can buy the RIGHT charger on the first time.
(You don't really need more than one
charger, Get the RIGHT ONE Get the Best!)
Neither ShaShinKi.com nor the
writer (KOH KHO KING) takes any responsibility to the accuracy or damage to
readers with the content of this article.
READ AT YOUR OWN
Types of Charger
In general, battery chargers can be
grouped into two:
1. Smart / Intelligent Charger
2. Timer based Charger
The characteristics of the two
Smart / Intelligent Charger
Timer based Charger
~ the charger is constantly measuring
the voltage in the battery. Once the charger detecting a preset
voltage in the charger, it will stop charging.
~ some better smart charger will
detect/measure the resistance when charging. A battery when about
full (95%) will have high resistance in receiving further current. A
better smart charger will then switch its charging current to a
lower one to continuously topping up the battery to 99.9% full.
~ the charger will continuously
pumping in current into the batteries for a preset duration of time.
Eg. 8 hours for most timer based charger.
~ If the power current to the charger
has been cut off during charging, the charger will start counting
its time/duration again from the beginning.
~ Timer based charger is meant for a
specific capacity of battery. If you use a timer based charger to
charge a battery that is larger capacity than what it is original
designed for, then you will not get full charge.
(eg. If the charger is meant for
2000mAh batteries, then you will not be able to charge a 2500mAh
batteries full with the charger, unless you overcharge it by
doubling the time/duration of charging)
Which type of charger is yours?
A simple test can be performed to
check if your charger is timer based or smart type.
1. Fully charge your batteries
overnight using your current charger. Wait till the indicator on the charger
that shows FULL (you should dump your charger if it doesn't have a FULL
2. Switch OFF the power of the charger
with the batteries still inside the charger (that you have just charged to FULL)
3. Switch the charger back ON
4. Let the charger continue charging
the batteries for 10 to 15 minutes
1. A smart type charger will show FULL
sign within the 15 mins time, since the batteries have just been charged full
2. A timer based charger will
continuous charge the batteries for many hours as preset in the charger
Advantages / Disadvantages
Which is a better charger? Timer based
or Smart type? The answer to is no brain, of course the smart type, but why?
Continuous pumping current to the
batteries even after it is full is doing harm to the batteries. This will
shorten the life-span of the batteries. Using a battery that isn't fully charge
is wasting the actual capacity that the battery is capable of delivering. You
will not want to buy a 2500mAh battery and charge it only upto 2000mAh right?
Spending long hours charging is dreadful...especially if you are in a rush. Most
timer-based charger are slow type (which is also known as slow charger), and
takes hours (5 to 10 hours normally) to fully charge the batteries it is
The only reason to buy a timer-based
charger is due to its low price. With the simple design and features that it
offers (nothing besides charging for a long period), manufacturer is capable of
producing timer based charger at a very affordable price. However, as a
consumer...you are actually paying more for it in long run, as it shorten the
life of your batteries and the frustration of not knowing the condition (Full,
Half-Full, Empty?) of your batteries. So, you will end up buying another charger
(smart type this time) and wasting on the first timer based charger. I know this
because the first charger that I bought after entering into photography is a
timer-based one (more than 12 hours...), dumb it within one month and spent
double the price for a smart type later, well worth it! Should have bought a
smart one in the first place.
Timer Based Charger
A timer based charger is also known
as a low cost charger, hence most of this charger will only have one constant
charging current to the battery. Most timer based chargers are using 200mA/hr as
their standard charging current.
There are various types of smart
charger in the market. Most smart charger will have high charging current which
are also known as Fast Charger or 1 Hour Charger or Quick/Super Quick Charger.
These chargers normally uses charging current from 800mA to 2000mAh to super
quick charge the battery. Side effect to this is high temperature to the
battery. Some batteries might yield very high temperature that endanger the
user/surrounding. Hence, buy a reliable smart charger that has a temperature cut
off detector (auto cut off the power when detecting high temperature on the
one hour worldwide charger is using 2000mA as the initial charging current with
temperature cut off feature. When the charger detects the batteries to be 98%
full, it will switch to Top-Off Charger and then Maintenance Charge (also known
as trickle charge) mode that continuous pumping in current to the battery at
50mA. This charger is also known as the best charger in the world that is able
to charge the batteries to 99% full with its
CHARGING PROCESS. More more review of the charger,
~ Maha C801D Eight Batteries One
Hour Charger is also using 2000mA current when charging. It also features the
same trickle charge mode at 50mA charging current when the batteries is at 95%
~ La Crosse BC-900 is the only
smart charger that I know of in the world that has the ability to user
selectable charging current from 200mA to 1000mA. You can select your desired
charging current depending on your need/speed/time have. It also features
trickle charge mode to top off the remaining capacity of the battery and keep
the battery full at all time.
* cool charging of batteries means
charging at 200mA or lower. Your batteries will not have significant temperature
increment during charging
* trickle charge means charging
batteries at a very small current. Different manufacturers use different trickle
charge current, but normally is around 20mA. Trickle charge mode will do no harm
to the batteries, in fact it keeps the batteries full at all time. Users can
leave the batteries in the charger for an extended period and remove the
batteries from the charger right before using. As NiMh batteries looses out the
power over time, thus it is advisable to get a smart charger with trickle charge
mode and keep a set of batteries constantly in the charger charging to remain
the constant full charge.
Timer Based Charger
Most timer based charger has only
one charging circuit, meaning that you need to insert all two / four batteries
into the charger in order to start charging. There is no detector built into the
charger, and the charger will continuous charging the batteries on the preset
time/duration as long as it detects the complete circuit of the batteries.
Smart charger nowadays varies from
1 to 8 independent charging circuits when charging (Maha C801D is having 8
independent circuits for each and every one of the batteries that it is
charging). A better smart charger will have independent charging circuit for
every single battery that it is charging. Independent circuit means that the
charger is monitoring the condition of every battery that it is charging with
different circuit/voltage/resistance detector. For example, Maha C801D with 8
independent circuits will charge every single batteries FULL by measuring the
voltage and resistance of the batteries individually. It will not be affected by
the condition of the batteries next to it. One can mix different capacity of
NiMh batteries in the charger (eg. 2000mAh mixed with 2300mAh and 2500mAh or
even 2700mAh in future) and the Maha C801D charger will charge every single one
of the batteries full at its own time, and trickle charge it afterwards.
Maha C204W is
having 2 independent circuits for the 4 pieces of AA batteries that it is
charging. It uses one circuit to monitor the charging condition of two pieces of
batteries. It is fine for those who uses the same capacity of batteries (eg.
4pcs or 2 pcs of PowerEx 2500mAH), but it is not recommendable if you were to
mix 4 different capacity of batteries (eg. × 2100mAh +
2300mah + 2500mAh + 2700mAh). The reason is because the the circuit will detect
the smaller capacity battery (2100mAh) full earlier than the other batteries and
switch to trickle charge mode. However, if user were to charge two 2300mAh
batteries + two 2500mAh batteries, place the same capacities batteries on side
by side onto the charger and the
will still be able to charge both to FULL, and trickle charge to top up the
La Crosse BC-900 charger is using
4 independent charging circuits for every piece of batteries that it is
charging. User can mix any capacity of NiMh batteries charging through the
BC-900 at one time (eg. √ 2100mAh + 2300mah
+ 2500mAh + 2700mAh). La Crosse BC-900 charger will charger every single battery
FULL and switch to trickle charge mode after that. User can even set/select
different charging current on the 4 different circuit (eg. 200mAh 500mAh 300mAh
Timer Based Charger
I have not known of any timer based
charger that has the discharge mode, as most timer based chargers are meant for
low cost production...hence making the charger as simple/low cost as possible.
Not all Smart Charger will have
Discharge/Deep Cycle/Revive Batteries mode.
In theory, NiMh battery has no
memory effect. It means that once can charge the NiMh battery regardless of how
much power is remaining inside the battery. The battery that is charged full
will deliver every drop of juice till it is completely depleted. In THEORY
(theory is something that can never be achieved in real life but only on paper).
In real life, there is still very
small memory effect built up in NiMh battery. Most NiMh batteries will have
around 500 cycles life. It means you can charge the NiMh battery upto 500 times.
After its life, current is hardly able to pump into the battery and vice versa.
(NiCd batteries is well-known to have large memory effect, thus not popular
among photographers in the world)
A better smart charger will have
the capability to discharge your battery before charging it. It is recommended
to discharge your batteries completely after every 10 ~ 20 cycles. This will
keep your batteries in top performance. I will write another article on
batteries in future.
Deep cycle is the ability of
the charger to charge / discharge the batteries automatically for 3 cycles
without user's interruption. Just press the deep cycle mode and the charge will
discharge the batteries till empty, then charge them till full, then discharge,
then charge, then discharge, then charge...Different charger will have different
number of discharge / charge cycles, depending on the manufacturer.
Revive battery mode is the
unique offering by the latest Maha chargers.
Maha designed a special
"ramp-up" charge that "jolts" the batteries if needed to revive old batteries.
This happens in the first two minutes after the battery insertion. This
"jolting" is a series of carefully timed high current pulses that can activate
both new and inactive batteries. From the customer's point of view, they can put
batteries of different health levels and rely on the charger to give them a