RE: 2700mah Batteries and Peak Chargers
Hello Dustin, If you review the Sanyo [url=http://www.sanyo.co.jp/energy/english/spec/twicell/HR-AU.pdf]data sheet,[/url] you will find that Sanyo recommends a fast charge of 1C with proper charge termination. It looks like they use a -dV value of 10 mV, but I happen to think that is a little high, and you may experience some heating as a result. In general, Sanyo recommends charging in the 0.5 - 1.0C range, which for 2700 mAh cells is 1350 - 2700 mA. This is the recommended charge rate range when using chargers that terminate on changes in voltage or changes in temperature. The other recommended charge rate is 270mA with the charge terminated after 16 hours of charging. In a battery pack, this works great as long as all of the cells within the pack are balanced. This is where the problem is. The higher capacity NiMh cells have thin separators and tend to form high self discharge rates after very few charge/discharge cycles. Unfortunately, not all cells develop this high self discharge rate uniformly. This means that you may have 1 or 2 cells with high self discharge rates within your battery pack, and the pack will be severely out of balance. Now, when you charge at the recommended 0.5 - 1.0C rate, you will end up overcharging some cells as the high self discharge rate cells will take longer to charge. This will result in hot cells and damage to the better cells because of the heat. The interesting thing is that these cells work very well the day that you charge them. It is just when you let them sit for a few days that they get out of balance. When you test them, they have good capacity and hold good voltage under load. Their only "issue" is that they rapidly self discharge. The work around is to do the 16 hour 0.1C charge rate each time. This will balance the cells in the pack even if they are severely out of balance. The other work around is to do frequent charge/discharge cycles. Another work around is to charge each cell individually, but this can be difficult if the cells are built into a pack. Tom
Posted on: 2/21/2009 12:20 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=8501630

RE: Dead lipos
Hello WO, While not recommended and extremely dangerous, the way to bring the voltage of an over discharge pack with the Triton is to set the Triton to charge a NiMh pack and adjust the current to charge at 100 mA. Sit there and watch the voltage of the pack (cell) come up. Don't leave, don't watch TV, don't answer your phone, don't go to the bathroom, just watch the voltage. Once the voltage get above 3 volts per cell, stop the charge. Now you can switch over to normal charging and the Triton should recognize the pack (cell). I would caution you to pay close attention to the first few charges after this. Most of the incidents occur during charging. If you notice increased heat or puffing, stop the charge and recycle the pack (cell). Tom
Posted on: 1/15/2009 2:45 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=8361540

RE: What forming charge??? Help Please???
Hello Rodney, I agree. The "reduced rate long term charge" available in most chargers does a lot of damage to cells left in the charger for extended periods of time. This problem is amplified with the newer low self discharge cells like the Eneloop cells. There are a few chargers that acknowledge this issue by either shutting off after the charge has completed, or have reduced the extended charge rate to something very low. Of course the proper way to use batteries is to charge them up and use them, but we have been sold on the idea that since batteries self discharge, we would be better off leaving the cells in the charger so they would be always "ready to go." I am hoping that the low self discharge cells will revamp peoples ideas on this and they will be more responsible in their charging practices. Tom
Posted on: 1/12/2009 8:16 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=8351173

RE: What forming charge??? Help Please???
Hello Dan, Battery manufacturers use standards to rate their cells. The cells are given a standard charge, then the capacity is obtained from a standard discharge. The standard charge involves charging at 0.1C for 16 hours. The charge is terminated with a timer. The standard discharge is a 5 hour discharge that is terminated when the cell voltage reaches 1 volt. Sometimes this is stretched to 0.9 volts. The labeled capacity of the cell is obtained from this test. I was surprised to find that the manufacturers data sheets often list a fast charge and the performance of the cell is often shown after using this fast charge. Cycle life testing originally involved standard charges and standard discharges, but it also has an option for 1 hour charging. For example, [url=http://us.sanyo.com/dynamic/product/Downloads/AA_4Pack-49579479.pdf]here[/url] is a data sheet for the new Sanyo Eneloop cells. When you look at the discharge graph, it shows that this performance was obtained using a 1 hour charge. In addition to hobby Sub C cells, I use a lot of consumer AA and AAA cells. I have changed from overnight charging to 1-2 hour charging with all of my cells. I must admit that my chargers that are capable of 1-2 hour charging are much higher quality than those I was using for overnight charging with my consumer cells, but overall I have had much better results using the 1-2 hour charging. My cells are lasting longer, holding higher voltage under load, and seem to end up with lower self discharge rates. I now no longer use overnight charging as my regular method of charging. I use a standard charge as a forming charge for individual cells, and perodically to balance the cells in the pack. I then do a standard discharge and make a note of the capacity. That becomes my baseline for comparison. I then do the bulk of my charging at a 0.5 - 1.0C rate. The purpose of the standard (or forming) charge is to evenly distribute the electrolyte within the cell and to evenly saturate the seperator with electrolyte. Once this is done, the cell is good to go and if the cells in the battery pack are well matched, the pack should stay in balance over the next 10 - 30 charge discharge cycles, depending on use. After 20, or so, cycles, it is a good idea to once again do a standard charge to balance the cells within the pack. Please note that you can't charge cells in a battery holder at the 0.5-1C rate. The battery holders are not designed for that current, and they end up melting. This restriction is not because of the cells, but because of the high resistance connections in the battery holders. The best explanation I have for the increased life is that I am using a higher quality charger, and I think the cells cook themselves to death during extended trickle charging involved in overnight charging, especially if the cells only have been partially discharged before charging. This can cause damage, and this damage adds up. I have also noted that in order to get a good strong end of charge termination signal, the battery manufacturers recommend charging in the 0.5-1.0C range. This also goes for consumer cells. If you don't get a strong termination signal, you risk damage by overheating due to overcharging. Hobby cells perform better if they are heated up during charging. To heat them up people charge at high rates like 2C. While they do perform better, the price is reduced cycle life. It is interesting to observe that after some battery packs suffered from exploding cells, the push for higher charging rates has been somewhat dampened. Schulze makes some very good chargers and it is interesting to note that their chargers are now limiting the charge rate to 1C when using their automatic charge function. It appears that the benefits from charging at rates higher than 1C are not worth the safety risks involved. All in all I have had good results and now spend less time charging. Tom
Posted on: 1/12/2009 12:02 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=8349351

RE: NiMh AA charging rate?
Hello Boomchank, The charge rate depends on what your charger uses to terminate the charge... To get the strongest end of charge termination signal when using -dV or change in temperature termination, you should charge at a rate that completes the charge in 1 - 2 hours. If your charger uses a timed charge, the rate to shoot for is 1/10 of the capacity of the battery. For example, a 2100 mAh cell would be charged at 210 mA. The charge time is about 16 hours. Other chargers use a peak voltage to terminate the charge, then use a trickle charge to top off the cell and complete the charge. These chargers generally charge at lower charging rates. If you are in a hurry, there are also 15 minute chargers available. Charging at this ultra rapid rate does damage cells, but it is really convenient to have the batteries ready to go in a very short time. NiMh cells are supposed to be good for around 500 charge/discharge cycles. Using the 15 minute charger will reduce that down to around 150 charge/discharge cycles. Overcharging and heat is what kills NiMh cells, so you want to avoid that. Understand that you can overcharge a cell without it necessarily heating up. For example, if you are charging your 2100 mAh cell at 210 mA, you can leave it charging for about 6 months to a year and while it will never heat up, it will be damaged to the point where it will not work properly. It is always a good idea to check the heat of the cells during charging. If you are charging at lower rates, heat may not be the best indicator, so it is a good idea to set a timer. If it seems that something is not going right, simply stop the charge and figure out what is going on after that. Leaving cells overcharging will damage them. Tom
Posted on: 12/21/2008 3:20 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=8268035

RE: Graph 4200-5200 NIMH
Hello Guver, I see you are running your CBA in the 70 - 80 watt range. Have you read [url=http://www.camlight.com/techinfo/CamLight_Systems_CBA_II_Thermal_Analysis.pdf]this[/url] paper? Tom
Posted on: 12/21/2008 9:04 AM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=8267026

RE: Eneloop AA
The Eneloop cells are some of the newest cells available. They perform very well up to 4C and their low self discharge rate is a big plus. The consistency between cells is amazing. There are a lot of these cells in various services and they seem to perform well. Very few have been pushed to failure, but failure seems to involve over discharge and extended trickle charging. The are also damaged by excessive heat. There are other brands of low self discharge cells, but the Eneloop cells remain the flagship of this chemistry. They are very good in cameras because they hold a higher voltage under load than normal NiMh cells. Tom
Posted on: 12/19/2008 9:02 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=8263008

RE: CBA graphs
Hello Guver, Are you aware that the CBA is limited to 100 watt continuous? Actually the IC in it gets extremely hot if you go over around 60 watts. This tends to reduce the maximum amount you can draw for larger numbered cell packs. For example, an 8 cell pack would have a starting voltage of around 11.2 volts (8 * 1.4 = 11.2). 100 watts divided by 11.2 volts would be a maximum current draw of 8.9 amps. Now, if you invest another $500 and get the amplifier, you are good to go. Tom
Posted on: 12/5/2008 5:17 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=8216188

RE: 4600 Nimh only taking ~2000mah
Hello Galaxie, I use a Schulze isl-6 330d/RS. I have been thinking about upgrading to a Schulze Next Gen series... Tom
Posted on: 10/25/2008 11:10 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=8084997

RE: 4600 Nimh only taking ~2000mah
Hello Barber, All of that is very good... However, what you say if I told you I had a pack that not only would last longer than your pack, but would also offer more punch during its entire run? One way to verify this, and it eliminates some variables that crop up during an actual run, is to compare discharge curves for both packs. If my pack holds higher voltage and gives more capacity under load than your pack, my pack would be an improvement over your pack. If we lived next door to each other, we could simply go out and race, but since we don't its easier to run a discharge test and compare graphs. Another comparison would be if I had the same pack, but it was made from a new batch of cells, and found that I was getting 32 - 42 minutes from it. We could do a discharge test of your pack and my pack and see if there is a difference. You may want to consider developing an interest in discharge capacities... Tom
Posted on: 10/24/2008 8:26 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=8081943

RE: 4600 Nimh only taking ~2000mah
Hello Barber, Interesting... You do realize that the important number is how much you get out of your pack? The amount you put in is dependent on how discharged the pack is, and how well balanced the pack is. If you are putting a lot into the pack, it could indicate that your charger is missing the end of charge termination signal and overcharging your pack... The capacity numbers labeled on the cells are supposed to be discharge capacity, not the amount of charge put in. For example when you do a "break in" charge, you charge at 0.1C for 16 hours. A 4200 mAh cell would have 6720 mAh put in during this charge. When you discharge the cell after this charge, you hope to get 4200 mAh from it. Charging capacity is interesting... discharging capacity is what makes things go. Tom
Posted on: 10/24/2008 4:13 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=8081245

RE: How to test AA rechargeables...
Hello Kcobra, When charging at 0.1C, the charge efficiency is not all that good. You actually need to put in around 150% to come up to a full charge. The "forming" charge goes for 16 hours to make sure the cell is fully charged. The damage done by the extra hour of charge at this rate is minimal. The battery manufacturers follow an IEC standard when determining the capacity of their cells. The standard calls for charging at 0.1C, allowing the cell to rest for from 30 minutes to 4 hours, then running a discharge at 0.2C. The same standard also is used to determine cycle life. One of the methods used to determine cycle life involves charging at 0.1C for 16 hours. You are correct in that extended trickle charge is not good for NiMh cells, however a couple of hours at 0.1C is not considered extended trickle charging. Tom
Posted on: 7/21/2008 11:28 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7757632

RE: How to test AA rechargeables...
Hello Fasstrevo, When the LaCross BC900 came out, it was at the top of the heap. However, since then, Maha came out with their C9000 unit. It actually has a Break-In function that will charge your cell at 0.1C for 16 hours, then do a 0.2C discharge to determine the capacity of the cell, and finally charge it back up at 0.1C for 16 hours. This feature is not available on the BC-900, and I think it makes the C9000 much more attractive, even though it costs a little more. Tom
Posted on: 7/21/2008 11:03 AM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7754696

RE: "Breaking In" New Batteries
Hello Nikq, The purpose of the "forming" charge is to evenly distribute the electrolyte and charge throughout the cell electrodes and separator. My opinion is that the best results come from starting with a discharged cell and using the 0.1C charge rate for the full 16 hours. On the other hand, if you are trying to balance a pack, you can set the charge limit a little low, charge at 1C, then finish off the charge and balancing at 0.1C for a few hours. For example if you had a 4600 mAh pack and you are starting from a discharged condition, you could set your maximum charge limit to 3500 mAh, charge at 4.5 amps until you have put back the 3500 mAh into the pack, then drop to a 460 mA charge rate for a few hours to finish the charge and to bring the cells in the pack into balance. This works great for balancing, but I don't think it is the best way to go for "forming." Tom
Posted on: 7/13/2008 2:54 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7726161

RE: does my friends had a nimh problem?
Hello Carl, 0.1C for a 3300 mAh cell is actually 330 mA, but if your charger doesn't have that setting 300 mA will work. Tom
Posted on: 6/23/2008 12:12 AM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7649851

RE: does my friends had a nimh problem?
Hello Carl, The best way to balance the cells in a NiMh pack is to charge at 0.1C for 16 hours. For example if your pack is made up of 2000 mAh cells, 0.1C would be 200 mA. Tom
Posted on: 6/19/2008 6:24 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7638680

RE: does my friends had a nimh problem?
Hello Carl, The cells are out of balance and one, or more, of them is venting because it is being overcharged. It will quickly die. Tom
Posted on: 6/19/2008 1:01 AM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7636191

RE: Parallel lipos, question
Hello Guver, As Li-Po cells age, their internal resistance increases. If you parallel cells of different internal resistance, they will equalize at the same voltage and charge properly, but as soon as they are removed from the circuit their voltage will drop a little. You can verify this by charging the cells individually and observing if there is still a voltage drop at the end of the charge. Tom
Posted on: 6/10/2008 11:15 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7605505

RE: Parallel lipos, question
Hello Stew, With Li-Po chemistry and larger capacity cells, there is no problem at all. Let's assume open circuit resting volts, and let's pick a cell internal resistance of 0.03 ohms. If we look at the worst case we would have a fully charged cell (4.2 volts) paralleled with a fully discharged cell (let's go with 3.4 volts, although that is slightly over discharged), the difference in voltage between the two cells is 0.8 volts. Using Ohms law we find that the initial current is going to start at a little over 26 amps and drop down from there. For a 10 Ah cell, 26 amps is 2.6C, and 2.6C charging, while a little high, is not controversial. However, let's look at what happens with a 1.2 Ah cell. The same math applies, so we would have an initial inrush current of a little over 26 amps. Now were are into an area where there is some controversy. I don't think anyone recommends charging at around 21.6C. On the other hand, this is only a pulse load, and Li-Po cells can handle much higher pulse loads than steady loads. This initial current only occurs when you hook the two cells in parallel, then the current rapidly drops off as the voltages equalize. I have run a lot of tests on both Li-Po and Li-Ion cells doing this, and, if I remember correctly, the most I was able to measure was around 7 amps. Within 2 seconds the current dropped to around 3 amps, and after 10 seconds it was just a little over 2 amps and still dropping. I most likely missed the initial spike of current because my clamp meter was unable to pick it up, however the rapid decay in current indicates an exponential decay. Now the question arrises - Can your 1.2 Ah cell handle a burst of 26 amps, followed by a second at 7 amps, a couple of seconds at 3 amps, and a few more seconds at 2 amps before dropping to a charging rate under 2C? I have not tested every brand of cell, so I can't give you an answer. While I have suffered no ill effects, I don't have a good basis for understanding all the problems that could arise from doing this on a regular basis. When faced with uncertainty, you usually add "safety factors." In this case, the general consensus is to only parallel cells that are less than 0.5 volts of each other. This brings the initial surge down to around 16 amps and it will rapidly, within seconds, drop off to below 2C for most cells. I find that, depending on the degree of imbalance, cells hooked up in parallel will usually be balanced in 10 - 30 minutes. Tom
Posted on: 6/8/2008 2:33 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7594789

RE: single cell lipo charging question
Hello Apriliamille, To answer your original question, no balancers are needed for charging 1 cell batteries. Hook the cell up, select your chemistry and cell count and charge rate, and go. Tom
Posted on: 6/5/2008 10:48 AM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7583231

RE: charging LI-On batt with triton charger
Hello Bobby Bo, Li-Ion and Li-Po batteries operate at a different voltage than NiMh or NiCd batteries do. Each cell in a Li-Ion battery is a nominal voltage of around 3.6 - 3.7 volts. The Triton uses the cell voltage to determine how many cells (in series) there are in the battery pack you are trying to charge. If you select 3.6 for Li-Ion or 3.7 for Li-Po charging, that means you battery pack has 1 cell in series. If you select 7.2 for Li-Ion or 7.4 for Li-Po charging, that means your battery pack has 2 cells in series. From what you have said, this is what you have. As far as the charging current to use, Li-Ion and Li-Po chemistry is often charged at 1C. C refers to the capacity of the battery pack. If your battery pack has a capacity of 1200 mAh, a 1C charge current would be 1.2 amps. If your battery pack is really 4800 mAh, you may not be able to charge at 1C. I believe the Triton tops out at 2.5 amps, however charging at a slower rate is OK but it takes longer. There is a possibility that the cells in series in your pack may get out of balance. That means that the voltage of each cell may end up different with each other. When the voltage of a Li-Ion or Li-Po cell gets too high, it "rapidly vents with flame." People have gone to using balancers while charging cells in series, but some battery packs don't have the electrical connections for hooking up the balancer. Since there is some danger involved while charging, it is best to charge in an area that won't be effected by flames, fire, and smoke. Also, it is important to stick around and attend to the charge to make sure things don't go wrong during the charge. Charging outside on a concrete driveway is pretty safe, as long as you are upwind from the battery pack during charging. Tom
Posted on: 6/5/2008 10:40 AM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7583193

RE: TX Battery Question
Hello Geoff, Just charge it up. Tom
Posted on: 6/4/2008 6:04 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7580522

RE: TX Battery Question
Hello Geoff, Keep in mind that a big killer of NiMh cells is overcharging. When you charge at high rates, you need to be sure you send a strong termination signal to your charger so that it will properly terminate the charge and not overcharge. At the 0.1C rate, this is not a concern, and you simply set a timer and you stop the charge. You are the terminating factor. If you happen to go a little over, very little damage occurs at this rate. By now you know that for your 2100 mAh cells, the 0.1C rate is 210 mA. It is when you charge at a higher rate that you can run into problems. With NiMh chemistry, it is not recommended to charge in the 0.2 - 0.4C range if your charger uses -dV termination. With your 2100 mAh cells, this would be charging in the 420 mA - 840 mA range. Don't charge in this range if your charger terminates using -dV. The reason for this is because the -dV signal is not reliable or strong enough in that range to properly terminate the charge. The recommended charge rate is 0.5 - 1.0C. This means charging in the 1050 mA - 2100 mA range. This goes for both consumer and hobby cells. Keep in mind that if your cells are in a battery holder, the holder may not be suitable for charging in this range, so you are stuck with 0.1C timed charges. If your charger uses a change in cell temperature, or the rate of change in cell temperature, you want to be charging at 1C to produce a strong end of charge signal. Now, if your charger terminates when a peak voltage is reached, you can charge at any rate you want to. So, you first have to determine how your charger determines that the charge should be terminated, then you have to determine if your cells and holders can handle a certain charge rate, and finally you need to monitor the charge progress to make sure your back up termination works if the main termination is missed for some reason. I find that I get better performance from my packs and cells if I do a 0.1C charge for 16 hours every 20 - 25 charge/discharge cycles when I am charging at high charge rates. I would suggest that you start with discharged cells before doing the slow charge to limit the amount of overcharge. People say that fast charging reduces cycle life, and they are correct. When you are charging at 2 - 5C, you get a reduction in cycle life. If you have the time and can figure out how much you have used from your pack, 0.1C charging is the best way to go. The problem is figuring out how much you have used and adjusting your charging time accordingly. Overcharging at this rate is not all that bad, so you don't have to be exact, but if you leave your pack constantly trickle charging at this rate, you will ruin your cells in a little over a year. Charging is pretty straightforward once you figure out how your charger works. Take some time and get to learn all you can about it. Tom
Posted on: 5/30/2008 11:43 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7561828

RE: Sanyo 2500 mAh AA comes with 0 volts
Hello Robert, First of all, there have been a lot of reports of all brands of 2500 mAh cells developing high rates of self discharge. The seem to work well until you have around 15 - 20 cycles on them, then a lot of them go downhill from there. I think your 0 volt cell is toast, and would not trust it even if you are able to get a charge into it. Tom
Posted on: 5/29/2008 2:29 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7555925

RE: Schulze next 6.30-5 error charging single-cell NiCd/NiMh (error #11)
Hello Teryn1, Check page 21, section 12 of your operators manual. It looks like they changed things a little. Tom
Posted on: 5/25/2008 1:26 AM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7537184

RE: Schulze next 6.30-5 error charging single-cell NiCd/NiMh (error #11)
Hello Teryn1, I believe, when charging a single cell, you need to start the charge at the 0.1C setting, then as soon as the charge starts you can ramp up to the charge current you want to use. Tom
Posted on: 5/24/2008 3:47 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7535548

RE: Using AAA instead of AA batteries for receiver
Hello Bona, Yes. Tom
Posted on: 5/21/2008 4:54 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7524375

RE: 1 amp discharge?
Hello FatOrangeKat, If you are interested in seeing how well the actual capacity of your cell matches the labeled capacity, you need to charge for 16 hours at 0.1C, then let the cell rest at least 1 hour, but not more than 4 hours, then measure the capacity during a 0.2C discharge to 1.0 volts. If your cells is from a battery manufacturer, and not simple re-labeled by someone else, and is in good condition, it should come close to its minimum rating. You can go a step further and repeat this 500 times and see how well the cell holds up to charge/discharge cycles. Cycle life, under these conditions, is usually 500 cycles or more for NiMh chemistry. On the other hand, if you want to try to determine how well a cell will work in actual use, you need to charge and discharge at rates that you normally use. The capacities obtained under "real world" loads can be used to estimate runtime. Another way to compare the differences between different brands of cells is to set your own standard. You can compare the capacities of different brands using 1C charging followed by 1C discharging. You are hoping that the measured capacity comes close to around 95% of the labeled minimum capacity, but whatever the capacity comes out to, you will gain some insight into the performance of your cells. I happen to think that charging rate is more important than discharging rate, but there are times when the discharge rate is important. You can also do some testing to see what you come up with as far as these variables go. Tom
Posted on: 5/21/2008 4:52 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7524369

RE: Using AAA instead of AA batteries for receiver
Hello Borna, I am confused... Your receiver uses AA batteries and you want to replace with AAA batteries? There may be a problem getting them to fit. AAA cells are smaller than AA sized cells. AAA size cells have difficulty, in spite of their optimistic labels, getting to 900 mAh of actual capacity. If you are already using AA sized cells, just replace them with higher capacity AA cells. Tom
Posted on: 5/21/2008 4:05 PM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7524184

RE: Do you believe in form-charging?
Hello Clowkoy, Yes. Tom
Posted on: 5/14/2008 11:47 AM by Author "SilverFoxCPF" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=7494953