So many lithium batteries in my house. Cheap ones are fire hazards. I like that apple is looking out for me so that if I go to any place for apple parts and be reasonably sure they made it hard for them to sell counterfeit parts.
The problem isn't bad batteries. Li-ion batteries have been around long enough now that everyone has gotten pretty good at making them. The problems with Li-ion chemistry are:
It has a relatively flat voltage curve as it discharges. With other battery technologies, the voltage drops suddenly during initial use, flattens out, then drops suddenly when it approaches depletion. This makes it relatively easy to design chargers and discharge circuitry to stop pulling power when the battery is empty, and stop
That is not how charging Li-ion batteries works and is not why they explode or catch fire. Li-ion batteries are charged exactly the same as lead-acid batteries are, just with different voltages. The voltage curves look broadly similar, too. Ni-MH batteries are the kind which have the annoyingly flat curve, but this just means that you have to keep charging for a while after it reaches full voltage. You have to charge Ni-MH batteries in constant current mode and monitor the voltage to know when to stop charging Ni-MH, stopping when the voltage starts rising again, This is unlike Li-ion and lead-acid which finish charging in constant voltage mode and stop when the current drops below a certain point.
The main difference between Li-ion charging and lead-acid charging is that you MUST monitor temperature during charging with Li-ion, and throttle back the current/voltage if the temperature gets too high. If you don't, you'll risk thermal runaway, since Li-ion batteries start self-discharging at high temperatures, creating a positive feedback situation where the temperature causes more current to flow which raising the temperature which causes more current to flow, etc., until fire erupts violently.
As far as charging circuitry being included with Li-ion batteries goes, no, no, no, no, no, no, no. That extra circuitry sometimes on the batteries (if not, it's in the device) is protection circuitry. It monitors for fault currents, low voltage, reverse voltage, and high voltage/overcharging, and, sometimes, temperature, and shuts down the battery if any of those are detected. Fault currents lead to thermal runaways, which is bad, so you must prevent that from happening. High voltages happen when you overcharge or overquickly charge a battery and lead to thermal runaway. Low voltages are when the battery is drained too far. This causes the battery to lose capacity after only a few uses and so must be prevented. Reverse voltages can cause internal short circuits to occur by growing metallic whiskers between layers. Internal short circuits cause extreme fault currents in the battery which can't be stopped by the protection. This would be catastrophic, so the protection has to protect against reverse voltage as well. And, of course, protecting against overtemperature is sometimes done in the protection, but not usually. Temperature protection is usually done in the device, often with a probe in the battery.
Keep in mind that this protection circuitry is pretty much always the same. It's a DW01 chip and a dual MOSFET. Sometimes there will be an additional temperature protection circuit but this is fairly rare. Instead, the device monitors temperature and adjusts charging currents accordingly.
Now, one thing you're right about is knockoff battery makers not putting protection in their knockoff batteries in the past, but this is pretty rare today. Without protection, you could easily get bad situations, particularly if the battery wasn't up to the current specs of the original. This is because, higher currents than the battery can handle will lead to (you guessed it) thermal runaway. If the battery isn't up to spec and doesn't have protection and the device doesn't have protection that would be very bad.
Now as far as off-brand batteries blowing up Apple devices because Apple's charging circuitry is too specialized: no. The charging circuity will always be able to handle batteries of different sizes, because of how charging works. As long as the replacement battery has protection and thermal sensors, assuming the original had them, then it's no problem, and, if the original didn't, then it's doubly no problem.
The big danger of using an offbrand battery in an Apple phone is that of the physical dimensions being off. If the knockoff is slightly bigger in any dimension, then that could be a big problem. The reason is that Li-ion batteries expand by several percent as they charge. A fully charged Li-ion battery is something like 6% bigger than a dead one. If there isn't enough room for this expansion, then the battery will be compressed. If you compress a Li-ion battery enough (or any battery, for that matter), you'll cause an internal short, and then your device will be on fire. Just ask Samsung about the Galaxy Note 7.
Makes me even more confident when I buy apple (Score:0, Troll)
So many lithium batteries in my house. Cheap ones are fire hazards. I like that apple is looking out for me so that if I go to any place for apple parts and be reasonably sure they made it hard for them to sell counterfeit parts.
Re: (Score:3)
Re:Makes me even more confident when I buy apple (Score:2)
That is not how charging Li-ion batteries works and is not why they explode or catch fire. Li-ion batteries are charged exactly the same as lead-acid batteries are, just with different voltages. The voltage curves look broadly similar, too. Ni-MH batteries are the kind which have the annoyingly flat curve, but this just means that you have to keep charging for a while after it reaches full voltage. You have to charge Ni-MH batteries in constant current mode and monitor the voltage to know when to stop charging Ni-MH, stopping when the voltage starts rising again, This is unlike Li-ion and lead-acid which finish charging in constant voltage mode and stop when the current drops below a certain point.
The main difference between Li-ion charging and lead-acid charging is that you MUST monitor temperature during charging with Li-ion, and throttle back the current/voltage if the temperature gets too high. If you don't, you'll risk thermal runaway, since Li-ion batteries start self-discharging at high temperatures, creating a positive feedback situation where the temperature causes more current to flow which raising the temperature which causes more current to flow, etc., until fire erupts violently.
As far as charging circuitry being included with Li-ion batteries goes, no, no, no, no, no, no, no. That extra circuitry sometimes on the batteries (if not, it's in the device) is protection circuitry. It monitors for fault currents, low voltage, reverse voltage, and high voltage/overcharging, and, sometimes, temperature, and shuts down the battery if any of those are detected. Fault currents lead to thermal runaways, which is bad, so you must prevent that from happening. High voltages happen when you overcharge or overquickly charge a battery and lead to thermal runaway. Low voltages are when the battery is drained too far. This causes the battery to lose capacity after only a few uses and so must be prevented. Reverse voltages can cause internal short circuits to occur by growing metallic whiskers between layers. Internal short circuits cause extreme fault currents in the battery which can't be stopped by the protection. This would be catastrophic, so the protection has to protect against reverse voltage as well. And, of course, protecting against overtemperature is sometimes done in the protection, but not usually. Temperature protection is usually done in the device, often with a probe in the battery.
Keep in mind that this protection circuitry is pretty much always the same. It's a DW01 chip and a dual MOSFET. Sometimes there will be an additional temperature protection circuit but this is fairly rare. Instead, the device monitors temperature and adjusts charging currents accordingly.
Now, one thing you're right about is knockoff battery makers not putting protection in their knockoff batteries in the past, but this is pretty rare today. Without protection, you could easily get bad situations, particularly if the battery wasn't up to the current specs of the original. This is because, higher currents than the battery can handle will lead to (you guessed it) thermal runaway. If the battery isn't up to spec and doesn't have protection and the device doesn't have protection that would be very bad.
Now as far as off-brand batteries blowing up Apple devices because Apple's charging circuitry is too specialized: no. The charging circuity will always be able to handle batteries of different sizes, because of how charging works. As long as the replacement battery has protection and thermal sensors, assuming the original had them, then it's no problem, and, if the original didn't, then it's doubly no problem.
The big danger of using an offbrand battery in an Apple phone is that of the physical dimensions being off. If the knockoff is slightly bigger in any dimension, then that could be a big problem. The reason is that Li-ion batteries expand by several percent as they charge. A fully charged Li-ion battery is something like 6% bigger than a dead one. If there isn't enough room for this expansion, then the battery will be compressed. If you compress a Li-ion battery enough (or any battery, for that matter), you'll cause an internal short, and then your device will be on fire. Just ask Samsung about the Galaxy Note 7.