Archive for the ‘Useful Battery Articles’ Category


So far we have been testing and reporting the Amp-Hours (Ah) of the various batteries we have tested with the reason being that they are usually being rated in Ah regarding their capacity. But there is another unit that may actually give a better idea about the capacity of a battery and it is Watt-hours (Wh) when talking about batteries. This is precisely the reason why we have decided to also include not only the measured Ah in our battery tests, but also the Wh values – the good thing is that we actually should have all of these for the batteries we’ve tested so far and we are going to include the Wh results for all tests already done.

With each battery we usually have two important ratings, though both are usually revealed by the manufacturer only for rechargeable batteries – Voltage and Amp-Hours (usually written in mAh). Different batteries may have different voltages and capacities and normally you should do some math to know what you can expect from a battery if you know the power requirements of the device you need the battery for. Here is an example: an AA type of NiMH rechargeable battery that has a typical voltage of 1.2V and is rated at 2000 mAh (2 Ah) should be able to power a device requiring 2 Amps for 1 hour, or a device requiring 1 Amp for 2 hours and so on. However when measuring the actual battery performance lie in our tests you can clearly see that the starting voltage of a fully charger NiMh battery is higher than 1.2V and when the battery is considered discharged it is lets say 1V. So by switching from the Ah to Wh we can take into account the changing voltage of the battery while it is being discharged and get even better idea about its actual energy capacity, even though the Amp-Hours ratings usually do a good job for comparing batteries.

To get an estimate about the Watt-Hours rating of a battery you need to multiply the Amp-Hours by the Volt rating of the battery. So for the above example with 1.2V NiMH battery with 2 Ah capacity we are going to get 2.4 Wh, meaning that this battery can power a device with power consumption of 2.4 Watts for 1 hour, or for 2 hours if it uses 1.2 Watts and so on. But this is just an estimate, because as we’ve already said the voltage of the battery will vary while it is being discharged, so we need to do a thorough test measuring the full discharge cycle to get more accurate value. If you look at the discharge graph and the Amp-Hours in our battery tests with different loads you will see how the voltage is different at different load levels and this will also affect the Watt-Hour ratings as well.

Another thing that we are going to be adding soon are tables that will make it easier for you to compare the performance of all of the batteries that we have tested, of course the tabled results will be divided by battery type. This should allow you to quickly get an idea what could be the best choice for your particular needs for a battery…

If you are using various kinds of rechargeable batteries you might have trouble keeping them all in shape and maximizing their performance and life, the more the batteries, the harder it is and we are not talking only about NiMH batteries, but LiPo, PB as well as other various kinds. For example if you only use a couple of NiMH batteries, then probably a simple and slow charger could do a good job, but if you are using many batteries and not only NiMH, but also Lithium-based rechargeable ones you might want to get a more serious charger or even multiple charger in order to properly maintain and take full advantage of the rechargeability of your batteries. You probably have seen that rechargeable NiMH batteries offer up to 1000 recharge cycles and Li-Ion and LiPo batteries can go from anywhere between 100 and 500 cycles if properly used and maintained. But in reality most people literally kill their rechargeable batteries in just about few dozens of recharge cycles due to improper maintenance and it is very often due to a problem with forgetting to recharge or overcharging or discharging them. In order to fully utilize the potential of the rechargeable batteries and also do what they are supposed to – help nature by avoiding the use of so many primary batteries like Alkaline for example or even worse Carbon-Zinc ones, you need to pay some attention and use better chargers in order to maintain and use the batteries as they are intended to be…


We are starting with the MAHA Powerex MH‑C9000 WizardOne Charger-Analyzer, probably the single best charger for NiMH batteries out there. But this is more than just a charger for AA and AAA size NiMH and NiCD batteris, because it can not only Charge but also Refresh and Analyze, Break-In, Discharge and Cycle the batteries in order to maintain them in the best possible shape. The device has four independent channels, one for each battery, thus allowing you to have a different function for each of the battery you have there or just to work with a single or more batteries at the same time. The standard charging current is user selectable from 0.2-2.0A (200-2000mA) and the discharging currents can be between 0.1-1.0A (100-1000mA) in increments of 0.1A and you can of course have different current for each channel. Thanks to the extra functions besides the standard charge and discharge you can use this to always maintain the health of your NiMH/NiCD batteries, even if they are not used for a while or they were not properly charged or discharged for some time. The charger is great both in terms of functionality, reliability and quality and the only better thing than getting one Powerex MH‑C9000 is to get two in order to be able to have 8 slots and nit just 4 with a single one – that is especially useful if you have and use a lot of AA and AAA size rechargeable batteries. In fact we are using one of these chargers as a part of our test equipment and are planning to get a second one in the near future. If you manage to find the Memorex Pro Genux 1 charger you could have a chance to get the Powerex MH‑C9000 for less as this is a rebranded version of the MH‑C9000, so grab a better deal if you can with the rebranded model.


Now, if you need a good charger that can quickly properly charge and maintain a larger number of AA and AAA size NiMh/NiCD batteries the Powerex MH‑C9000 might not be the best choice with its only 4 channels per device. Yes, it does have more extras, but with the significant increase in the number of batteries having a more functions with menus and options could turn out to be a problem and a distraction, so MAHA has some other chargers that might be more interesting in such situations. MAHA Powerex MH‑C800S and MAHA Powerex MH‑C801D which are AA and AAA NiMH/NiCD battery chargers with 8 independent channels for charging batteries and the only difference between the two is the charging current. The Powerex MH‑C800S has a Rapid Charging Mode with 1.0А and Soft Charging Mode with 0.5A per channel and the Powerex MH‑C801D is with 2.0A and 1.0A respectively and both these also have a Conditioning Mode intended to help revive batteries that are not performing optimally.


If you need similar chargers to the 8-channel Powerex models with lower charging current and similar simpler use and good quality you might also want to check out the chargers made by the Japanese company Tensai. They have the very nice 8-channel Tensai TI-800L, 12-channel Tensai TI-1200L and even 16-channel Tensai TI-1600L chargers for AA and AAA NiMH/NiCD batteries with independent channels for each battery. The charge rate per channel here is fixed at 0.5A for AA batteries and 0.25A for AAA, so higher capacity batteries might need more time to be charged, but in other hand if you don’t need very fast charging, but you need charging of a lot of batteries a single 16-channel charger can be quite useful for some. These chargers also have a Conditioning Mode for maintenance of batteries that are not giving their best.


Another good option are the LaCrosse Technology chargers such as the 4-channel chargers LaCrosse BC-700 (RS-700), LaCrosse BC-1000 (RS‑1000) and the many other names that these go rebranded under. The smaller LaCrosse RS-700 does have a bit more limited functionality giving you the ability to use only 200/500/700 mA per channel (independently set) and the better LaCrosse RS‑1000 supports 200/500/700/1000 mA per channel (up to 1500/1800 mA if charging only two batteries). Both of these chargers also support battery Refresh and Test modes aside from the standard Charge and Discharge modes and are good and more affordable option as compared to the MAHA MH‑C9000, though not as powerful and feature rich. The good thing is that these can probably be easily found, even if rebranded under another name in some countries, unlike the MAHA chargers that may be harder to be found in some places.


So far we have covered some of the best chargers for AA and AAA size rechargeable batteries, but what if you need a more universal charger that can charge pretty much all of the more common battery chemistries? For example both MAHA and Tensai are also making specialized chargers for 9V NiMH batteries (8.4V NiMH), but they are not as powerful as their models designed for the more common AA/AAA batteries, and the same goes for other battery types such as the C or D size NiMH batteries. If we want to add LiPo, LiIon or LiFe batteries or even Pb batteries along with the NiCD/NiMH models and have them in a single device we need to look elsewhere. A good and very popular choice is the SkyRC IMAX brand of chargers and one of their most popular model the IMAX B6AC, the model we are using this in our test setup for Lithium-based rechargeable batteries. The SkyRC IMAX B6AC is designed to charge NiMH and NiCD batteries in packs of multiple cells (it can still charge single cells), so it is probably not the best choice for such cells, but it can be used for 9V NiMHs (though it is limited to minimum 0.1A charging current). Regarding Li-xx batteries, you can charge 1 cell up to 6 cell batteries with a charge current between 0.1-5.0A (up to 50W) and discharge them with between 0.1-1.0A (up to 5W), there is also a built-in balancing functionality to make sure that all of the individual cells are charged properly. You can also charge PB batteries with a voltage between 2-20V. The B6AC charger can be powered by either AC input (100-240V) or DC input (11-18V), there is a B6 only version that does not include a built in adapter for AC input. What you should be very careful with these chargers is when buying to make sure they are genuine and really made by SkyRC and not a cheaper fake copy as they have a lot of copies, also have in mind that SkyRC has these chargers rebranded for some companies such as Team Orion for example. SkyRC also makes more advanced and powerful models that are based around the base functionality of the B6, but even a B6AC should be enough for most. If you however use LiPo batteries with more than 6 cells for example or even 3S-4S batteries with higher capacities you might want to look for more powerful models. There are of course a lot of other Li-xx chargers out there that are more powerful or offer extra functionality, but the B6AC should be more than Ok for most of you that need to have a good charger and don’t want to go doing things like advanced testing batteries for example.


There are many types of single use and rechargeable batteries available out there and you have many options for use in devices that operate on the more common types of batteries, but the important question is what types of batteries will work best in different devices and situations? Starting with Carbon-Zinc batteries, these you would probably want to avoid as they are just a bit cheaper than the more standard Alkaline batteries, however their life and capacity are usually a few times less than what a standard Alkaline battery would offer, let alone a high capacity ones. So go for Alkaline batteries in devices that do not require a lot of power or are not always on such as remote controls for various devices, Alkaline batteries are also good for low power consumption device that are operating all the time. You can of course also use Alkaline batteries for devices that require more power such as a digital camera or a flash for a digital camera if you are not using it very frequently for example. If you are looking for batteries that need to handle higher current loads frequently, then you better think about going for rechargeable instead of primary batteries.

So, going for rechargeable NiMH batteries, but what type to use – the standard HiMH or the newer Low Self Discharge ones? Well, again it depends on the device you are going to be using them in. For example the standard NiMH batteries are not the best choice for use in low power devices such as remote controls, because of their faster self discharge even when not being used. On the other hand you can go for LSD NiMHs in a remote control without worrying about them self discharging in a year or two even if you don’t use the remote. Now, we said you can use the LSD NiMHs for low power applications, but for a remote control for example Alkaline batteries might be much better choice because they should normally last for a few years and will be much cheaper than a NiMH battery. The real strength of NiMH batteries is that they can handle pretty well in high load applications such as digital cameras or flashes that you are going to be using a lot and very frequently. Usually with NiMH batteries you would charge them right before you plan on using them with the idea that they will most likely be discharged from use like for example going to an event where you will take a lot of pictures. With LSD NiMHs you don’t need to recharge them right before you plan on using them, so it is more convenient, not to mention that when you pick them up at a store they will be pre-charged and ready to be used unlike with standard NiMHs that need to be charged prior to being used for the first time.

Generally speaking, there is no need to always go for the best or more expensive batteries as sometimes they may not work as well as you might expect in the device you got them for. You should consider what you need the batteries for and then decide which of these batteries will work best, and them you may consult our test results to see what battery performs best…