What is Some Important Terminology related to batteries and packs?
C = Capacity or charge current
1C = Charge the pack at 1x it's capacity (3000mAh at 3.0 amps, 2400mAh
at 2.4amps)
C/10 = Charge at 1/10th the capacity (3000mAh at 300mAh, 2400 mAh at 240mAhs)
Lio = Lithium based battery cell. Lio-Polymers, Lio-Ion are examples
Out of balance battery - pack is when some of the cells in the pack still
had some charge left in them while others have no charge remaining.
IR = Internal Resistance
Trickle Charge = A trickle charge is less than C/10 and is meant for continuous
charging for standby devices such as cordless phones
Slow Charge = C/10
Peak charge = Charge at 1C and Slow or Trick after pack peaks.
Fast Charge = Charging above 1C
What is the actual voltage of Powerizer '9V' batteries?
Powerizer 9V batteries have a nominal voltage of 8.4V. They are composed of 7 cells. Fully charged with no load they will read about 9.4V.
How do the different types of NiMH and NiCD chargers work?
There are basically 3 types of chargers for NiCD or NiMH. First, there
is the slow, or 'dumb' charger that charges at a rate that won't destroy
a battery when it's full and overcharging. These chargers take 12 hours
or more to charge the batteries the charger was designed for. They continue
to charge at this rate as long as the charger is connected to the battery.
These chargers can charge NiCD or NiMH but it's better for the batteries
if they are not left charging for days at a time. Second, there is the
timer charger. These chargers take about 5 hours to charge an empty battery
(of capacity the charger was designed for). There is a timer that stops
the charging or reduces to a trickle rate after a fixed period. These
chargers can under-charge or over-charge depending on battery capacity
and how far discharged the battery was at the start of charge. These chargers
work at a rate that can overheat a battery that's being overcharged. Then
there are the 'smart' chargers. These generally charge in 4 hours or less.
They rely on detecting when the battery is full to reduce the rate of
charging to a trickle. There are two ways to do this. The best chargers
use both methods. One is to monitor battery temperature, which rises rapidly
when the battery is nearly full. The other, called 'negative delta V detection'
takes advantage of the phenomenon that the voltage across a cell being
charged at constant current falls slightly when the cell is nearly full.
This voltage drop happens because of gas being generated and reabsorbed
inside the cell and also as a side effect of temperature rise. The voltage
drop is much more subtle in NiMH cells so an older charger designed for
NiCD won't detect the drop in NiMH and will continue to overcharge at
a destructive rate. Temperature sensing is more reliable but requires
a temp sensor to be well attached to the battery. Neg. delta V is easier
to implement (no extra connections or sensor). Brand new cells, old worn
out cells, or cells that have not been used for a long time (months) often
don't present the voltage drop. A number of cells in a series string can
present the voltage drop at different times, also 'fooling' the charger.
So batteries should be periodically checked for overheating when first
used on a smart charger.
Are NiMH rechargeable batteries better than NiCad batteries?
NiMH rechargeable batteries have superceeded NiCads in many applications because they have a higher energy capacity; don't incorporate Cadmium - a highly toxic element, and don't suffer a "memory effect" (gradual loss of maximum capacity). However, in certain very high drain applications (power tools etc.) NiCads still have the edge.
Is it safe to use higher capacity cells in my device?
Yes, Substituting higher capacity batteries for lower capacity ones of the same type is perfectly safe. They have a larger energy capacity, which means they can deliver a sustained power output for longer periods, and all of Powerizer's cells are constructed to the highest technical standards. They simply last for longer, it's just like putting more fuel in your petrol tank. Although they have a larger energy capacity, they don't release their energy more rapidly than lower capacity cells (their power output is the same), so there is no risk of any damage. It's the voltage that really matters in this respect, and this is the same regardless of capacity. Some devices (e.g. cordless phones) need an initial period on charge to get going, and with high capacity replacement cells this initial period will obviously be longer, but apart from that there are no differences in operation.
What does "2250mAh" actually mean?
It's a measure of the total charge capacity of the battery. mAh stands for milliamp-hour, the milliamp being a unit of electric current. A 2250mAh battery is therefore capable of delivering the equivalent of 2250 milliamps (2.25 Amps) for one hour.
Why do alkaline batteries run down so rapidly in my digital camera?
Alkaline batteries weren't designed to supply the high power drains demanded by digital cameras and other modern digital equipment. Despite having a large energy capacity, alkaline batteries aren't capable of delivering their energy rapidly enough to supply your digital camera, causing it to shut down. Digital cameras, and in particular their LCD screens, demand large electrical currents from your batteries. An alkaline battery's internal resistance means that it can't provide a sufficiently large current, so its voltage drops and the camera shuts down. This is despite there still being energy left in the battery! - don't throw alkalines away when they fail in your camera, use them in a low power device.
NiMH batteries are able to power your device for very much longer than alkalines - enabling hundreds rather than handfuls of photos to be taken - they are also rechargeable again and again. Digital photography with NiMH batteries is not only more convenient, but can be done at a tiny fraction of the cost using alkalines.
Can I solder wires directly to my batteries?
Many people in the RC field make their own packs this way, but it is not the right way. You stand a great chance of destroying your batteries or shortening their life. Always use cells with solder tabs. Read this link for more details:
http://www.rcbatteryclinic.com/soldering.html
Why is putting batteries in parallel a bad thing?
Discharging NiMH or NiCD in parallel is not a problem. Charging however is. When Ni based batteries are being charged their voltage rises until they are nearly full, then the voltage drops. 'Smart' chargers take advantage of this to detect when the batteries are full. It's called negative delta V detection. If two strings of cells are in parallel while being charged and one string fills first its voltage will drop and 'hog' all of the charge current. This will result in overcharging/overheating.
What Are The Different Types of Rechargeable Battery Chemistries and Technologies?
Batteries in portable consumer devices (laptops and notebooks, camcorders,
cellular phones, etc.) are principally made using either Nickel Cadmium
(NiCad), Nickel Metal Hydride (NiMH) or Lithium Ion (Li-Ion) technologies.
Each type of rechargeable battery technology has its own unique characteristics:
NiCad and NiMH: the main difference between the two is the fact that NiMH
batteries (the newer of the two technologies) offer higher energy densities
than NiCads. In other words, pound for pound, NiMH delivers approximately
100% more capacity than its NiCad counterpart. What this translates into
is increased run-time from the battery with no additional bulk to weigh
down your portable device. NiMH also offers another major advantage: NiCad
batteries tend to suffer from what is called the "memory effect".
NiMH batteries are less prone to develop this dreaded affliction and thus
require less maintenance and care. NiMH batteries are also more environmentally
friendly than their NiCad counterparts, since they do not contain heavy
metals (which present serious landfill problems).
Li-Ion has quickly become the emerging standard for portable power in
consumer devices. Li-Ion batteries produce the same energy as NiMH batteries
but weigh approximately 35% less. This is crucial in applications such
as camcorders or notebook computers, where the battery makes up a significant
portion of the device's weight. Another reason Li-Ion batteries have become
so popular is that they do not suffer from the memory effect AT ALL. They
are also better for the environment because they don't contain toxic materials
such as Cadmium or Mercury.
How Are Batteries Rated? (What Are Volts and Amps?)
There are two ratings on every battery: volts and amp-hours (AH). The AH rating may also be given as milliamp-hours (mAH), which are one-thousandth of an amp-hour (for example, a 1AH battery is 1000mAH). The voltage of the new battery should always match the voltage of your original. Some of our batteries will have higher amp-hour ratings than the original battery found in your device. This is indicative of a longer run-time (higher capacity) and will not cause any incompatibilities.
My New Battery isn't Charging. What's should I do?
New batteries are shipped in a discharged condition and must charged
before use. We generally recommend an overnight charge (approximately
twelve hours). Refer to your user's manual for charging instructions.
Rechargeable batteries should be cycled - fully charged and then fully
discharged - 2 to 4 times initially to allow them to reach their full
capacity. (Note: it is perfectly normal for a battery to become warm to
the touch during charging and discharging).
New batteries are hard for your device to charge; they have never been
fully charged and are therefore "unformed". Sometimes your device's
charger will stop charging a new battery before it is fully charged. If
this happens, simply remove the battery from your device and then re-insert
it. The charge cycle should begin again. This may happen several times
during your first battery charge. Don't worry; it's perfectly normal.
What is the suggested Charging Rate for batteries?
Here are some of the charging rates for fast chargers, (any NiMH/NiCd type charger is ok)
- 700mAh "AAA" 1.2A maximum
- 2000mAh "AA" 2.0A maximum
- 2250mAh "AA" 2.0A maximum
- 2700mAh "A" 2.5A maximum
- 3000mAh sub "C" 3.0A maximum
- 4500mAh "4/3A" 4.0A maximum
Any High charging current may take risk to damage your batteres (leaking,
overcharging..)
You must decide how long to charge depending on how much power is needed
to bring the pack to full power.
Should I only Charge batteries Once a day?
Batteries don't keep track of time, they don't know if it's today, tomorrow or yesterday. As long as you allow them to cool down before putting them back on charge, you can charge them as many times as you like. Of-course the more you use them the less time they'll last in terms of years, but not in terms of cycles.
What does "Out of balance battery" mean? How to Fix it?
Out of balance battery
Pack is out of balance is when some of the cells in the pack still had
some charge left in them while others have no charge remaining. So when
you charged the pack three of the cells peaked before the others did.
That would leave the other cells a little under charged. So when you ran
the pack out the undercharged cells dumped before the fully charged ones
causing the under charged cells to feel warm. Cells begin to really heat
up when they reach their "dumped" point.
Fixing an Out of Balance pack - The C/10 charge theory
Just do a C/10 (c = capacity i.e. 2400mAh pack is charge 1c at 1.2A) charge
for 14-16 hours, the magic of "slow charge" is that it equalizes
the cells. As the cells fill up some will get full before others, but
at the C/10 rate there is no danger of over charging because the cells
that are full can safely dissipate the "over charge" as heat,
without damage, giving the other cells time to fill up. This is also why
it's a good idea to occasionally C/10 charge all your packs, in normal
use over a number of cycles they will start to become unbalanced and the
C/10 charge will rebalance them. Setting a C/10 trickle rate after a pack
peaks will also do this, the pack will peak when the first cell or two
does, but the others may not be quite full yet, if left at the C/10 trickle
for some time after peak the cells will rebalance. Some people say that
they see a reduction in power if the trickle charge after the pack has
peaked, stating they perform best hot off the charger. This is not as
noticed with NiCds but it does seem to be true for NiMHs, but Suspicions
are it is temperature related as NiMHs always seem to perform better when
warm and the time spent trickle charging will let them cool.
What does unit "C" mean during the Charge and Discharge procedure ?
In battery industry, people use full capacity of battery as rating.
If a battery's capacity is rated 2000mAh,
then
1C rate means recharging or discharging battery at current of 2000 mA,
e.g 2A
2C rate means 4A current
3C rate means 6A current
.
.
10C rate means 20A current.
High C discharging, will result in less working time of battery, for
example
Fully charged 2000 mAh NiMH batteries, if discharging at 1C rate ( 2000
mA current ), can last as long as 1 Hour
If discharging at 2C rate , they can only last 0.5 hours.
Meanwhile, high C rate charging and discharging will cause battery less capacity and shorter cycle life.
How well will NiMH Batteries work in Flash Units and Film Cameras?
1800/2000 mAH NiMH Batteries will all work very well in flash Units, and film cameras as well. Many professional Photographers and are now using only NiMH Batteries in all their equipment in place of standard AA batteries.
Does temperature effect the charging of your NiMH batteries?
Yes, but usually only if charged outside of the optimum temperature range of 0°C to 45°C when Slow Charging and +10°C to 45°C when Fast Charging. See the below for more detail
Typical Battery Charging Performance of NiMH Battery Cylindrical Cells
Charge
Standard Charging: Charging at 0.1C standard rate for 14-16 hours
will greatly enhance the NiMH battery's service life. Our NiMH batteries
can withstand overcharge at 0.1C rate indefinitely. Charging at or below
0.1C rate is suitable across a temperature range from 0oC to +45oC.
Fast Charging: All our NiMH series can be fast charged at rates from 0.5C to 1C. Fast charge termination measures should be employed. These include: Temperature Cut-Off (TCO), Rate-of-temperature rise (dT/dt), negative Delta V (-dV). A timer control set at 105% of nominal capacity can be used as an additional protection. For maximum capacity, a trickle charging can be applied after fast charging. We recommend top-off trickle charging at 0.1C for 2 hours or 0.2C for 1 hour. Fast charging can be done at temperatures from +10oC to +45oC.
My Digital Camera uses 1.5V "AA" batteries and your NiMH "AA" batteries are 1.2V. Will they still work ?
Yes, you can safely use NiMH batteries without any problems. They can be used in place of your original batteries in almost all digital cameras , film cameras, flash units as well as most other electronic equipment. Actually when they are fully charged they will measure around 1.4V+ per cell . NiMH (Nickel Metal Hydride) batteries are the most popular choice for digital camera users, photographers, cellular phone and laptop users, and many others because these batteries have a much higher capacity, have high drain properties, and are virtually memory free. These batteries do not need to be discharged every time before recharging.
Can I use NiMH rechargeable batteries instead of ALKALINE batteries in my camera or other equipments?
For any device that consumes a lot of power -'eats batteries' - NiMH rechargeable batteries are ideal. Just use your "high" power NiMH batteries in place of your alkaline batteries. Some confusion is caused by the 1.2V rating of NiMH batteries compared with the 1.5V rating of alkaline batteries. In fact alkaline batteries only supply 1.5V during the early stages of their discharge and this drops to below 1.2V for most of their life. NiMH batteries actually sustain a higher voltage than alkalines during the bulk of their discharge.
What can I do to maximize the life of my NiMH batteries ?
Althought there are many things that will maximize the life of your NiMH batteies we have listed the most important below:
* Never drop NiMH batteries on a floor or hard surface. This can severly
damage them.
* Be sure to use a well designed charger that will prevent overcharging
. This is probably the biggest cause of premature failure of NiMH batteries
- improper and over charging. Fastest is not always the best.
* Never carry NiMH batteries loosely in your pocket. Coins, or other metal
items could cause them to short, thus causing severe burns, or even a
fire.
What is meant by "no memory effect" on NiMH batteries?
Memory is a type of problem that traditional NiCD batteries usually develop. You probably have heard that in order to maintain the life and performance of rechargeable batteries, you have to fully drain the batteries before recharging them. Thanks to "memory free" technology used for NiMH batteries, you can charge them anytime you wish, regardless if the batteries are fully drained or not.
My camera came with 1600mAh Batteries. Can I still use 1800mAh Batteries or will they hurt my camera by being to strong.
Sure you can use the 1800 mAh batteries. 1800mAh denotes the capacity of a battery, not its strength. Capacity is how much charge a battery holds once it is fully charged.. The more capacity, the longer a battery will last in any given application. Voltage is the strength. Rechargeable batteries actually develop around 1.4 to 1.45 volts when fully charged even though they are marked as 1.2V.
I just received my NiMH batteries. Do I need to charge them prior to using them for the first time?
Yes, before you use your new NiMH batteries for the first time you must charge them fully. Please note that for new NiMH batteries, it is often necessary to cycle* them at least three to five times or more before they reach peak performance and capacity. The first several times that you use your NiMH batteries you may find that they run down (discharge) quickly during use. Not to worry, this is normal until the batteries actually form up.
*What do You mean by "cycle" ?
1. Charge your batteries fully.
2. Allow them to cool before placing them into your camera or equipment.
3. Use your equipment as you normally would until the batteries are discharged
and need to be recharged.
This is one complete cycle.
Do some chargers have a charging limit for the mA they can charge or handle or can all Nimh chargers handle any mAh rating?
Some chargers do have a limit on how much they will charge. This is true with many timer comtrolled chargers. For example if a charger charges at the rate of 220 mA and charges for 7 hours then automatcally shuts off, it will only deliver 1540 mA. So you wouldn't want to charge 1600 mAh batteries with this charger since your batteries could not receive a full and complete charge. However if you were to select a smart charger, then you could basically charge any capacity of battery the charger was designed to fit. Most?"smart chargers" are designed to switch to trickle mode once it detects that your batteries have been fully charged.
What are the Exact Sizes of so many different Batteries?
Good Question, Please take a look at This Chart
http://www.batteryspace.com/page.asp?id=3#Industrial
Is there any special requirement to replace a old Battery?
When buying a replacement battery, the voltage must be the same as the original battery, the dimensions and contact location must fit the device, but the Capacity(Ah) rating can vary.
How to Charge Your Batteries With a Timer Charger ?
Use this method to properly charge your batteries to get the most out
of them.
Here's How:
* Hook up your charger to the wall outlet or your 12 volt power supply
as required
* Attach your battery pack to the charger in the normal way.
* Feel the temperature of the battery pack, it should be at room temperature.
* Start charging the pack using the normal method for your charger.
* Every 5 minutes or less, feel the temperature of the battery pack.
* If the pack temperature is the same as before, keep charging.
* If the timer expires, start the charging process again.
* You should now check the temperature of the battery pack every couple
of minutes. Once the packs starts to get warm, turn off the charger.
* Unhook the battery from the charger, install the battery in your car
or truck and have fun.
Tips:
* Never allow your battery to over charge. It should only get slightly
warm when charging. Overcharging your battery can cause it to explose
and may cause bodily injury.
* Always let your battery pack cool down to room temperature before charging
it again. Failure to do so may decrease performance and cause premature
failure of the battery pack.
How to Discharge Your Batteries?
(Increase performance and the life of your batteries with proper care.)
A simple device to discharge your batteries
Here's How:
1. Construct a discharge device by attaching two wires to an automotive
tail light bulb.
2.When you are done running your car, attach the discharge device to your
battery pack.
3.Watch the bulb, when it starts to go dim, remove it from your battery
pack.
4.Ideally, you should only use your battery pack once per day, if this
is not possible, make sure it is fully cooled before charging it again.
Tips:
1.Always discharge your batteries after use.
2.Never charge your batteries if they are still warm from a previous use.
How many times can I recharge my batteries?
The number of times you can recharge your batteries will depend on the operating parameters, such as drain rate, battery care, etc. In general, under desirable condition, NiMH can last 500 recharges. In best condition, (0.1C charging and 0.2C discharging) NiMH can last up to 1000 recharges.
Can I replace NiCD with NiMH batteries?
Yes you can use NiMh in place of NiCD but you must understand that the charging times will increase due to the extra capacity of the NiMH batteries - and this is only if the charging circuits of your charger are capable of charging the Nimh batteries completely.
Will Quick charging NiMH batteries reduce their life?
Actually, all NiMH batteries required 3-4 times deep and slow charging
processing before reaching its peak capacity.
If you like quick charger, it is important to use a charger that has been specifically designed . Some low quality quick charger will slightly decrease the battery life. However, there is a greater likelyhood of reducing the life of a NiMH battery by using an "overnight" charger than by using a smart fast charger. Overnight chargers rely on the fact that you will unplug them after a number of hours, unless it is time controllered. If you forget to unplug them they can continue to charge the batteries longer than they should. Overcharging Will reduce the life of batteries. [From a strictly technical sense, a battery that is always slow charged will likely last a little longer than one that is always rapid charged] However, the difference is not big for most users.
What is Cycle Life for a Li-ion/Polymer battery?
Generally Speaking, Li-ion/Polymer cells will retain 80% of their original capacity after 400 cycles. A cycle is further defined as a full charge (4.2V) followed by a full discharge (2.8V). Cycling or storing the cells are elevated temperatures will reduce the cell capacity and cycle life. conversely, storing cells discharged and at low temperatures will extend the shelf life of these batteries.
Will the Li-ion/Polymer battery function properly after it sits unused for a long time?
Yes, the recoverable capacity of cells stored for over one year at room temperature and fully charged is 94%. The retained capacity of these same cells is 87%. This means the self-discharge rate for fully charged cells was approximately 150 mAh per year or 427 uAh per day. The self-discharge rate for cells is non linear, a partially charged cell has a self-discharge rate of about 80 uAh per day.
Does Lithium-ion have a memory?
No, unlike some other rechargeable battery chemistries, Li has no memory effect. In fact, Lithium-ion cells offer extended cycle life when cycled at low depth of discharge.
How do overcharge & over discharge affect the Li-ion/Polymer battery?
Optimum charge and discharge parameters are defined during the design of the Li-Ion/Polymer cell. Overcharge (voltages > 4.2V /cell) and over discharge (voltage < 2.4V / cell) will cause irreversible chemical changes to the cell. These charges will reduce the retained capacity and cycle life of the battery.
Are Lithium-Ion & Lithium Polymer batteries safe?
Yes Lithium-ion & Lithium Polymer batteries are safe. General concerns have been raised regarding the safety of Li-Ion/Polymer cells because of the high energy contained in each battery. In fact, any battery is unsafe if mishandled. Unlike Lithium primary cells there is no free Lithium metal inside Lithium-ion/Polymer rechargeable cells.
If Li-Ion/Polymer batteries are so safe, why must I use a safety IC circuit?
Safety Protection IC circuits are not only used to protect the cell and application from excessive discharge and charge currents, but they also maintain the nominal operating conditions for the cells. Protection circuits are designed to open a pair of series MosFet’s (metal-oxide-semiconductor field-effect transistor ) if the cell voltage exceeds 4.35V / cell or drops below 2.4V / cell. This ensures the cell will operate within the optimum design parameters enabling maximum capacity and cycle life to be obtained.
Information courtesy BatterySpace.com Forum