LiPo Batteries, the background
Lithium based batteries.
Chances are very likely that you have many lithium-based batteries in your home right now. Lithium ion batteries power your cell phone. laptop computers and other devices. Chances are very likely that you've never had any real issues with these batteries other than they die and they are difficult if not impossible to replace.
But, you should beware You remember the houses burning down a few years ago due to hoverboards catching fire? Then there was the Samsung Note 7 that was banned on all commercial air flight because it too would catch on fire when charging. At least it was known to happen, here and there.
And speaking of things that are hard to explain, why are the airlines so paranoid about this phone? Do you remember the Malaysia Airlines Flight 370? 239 souls lost at sea, bits and pieces of the plane were found washed up on beaches thousands of miles away from where it was last seen. Among the many conspiracy theories was one that I found, well, perhaps credible. There were 500 pounds of Motorola Walkie Talkie batteries on the plane. Here's the whole scenario. At the center of the scenario is once again, Lithium Ion batteries.
Lithium Polymer batteries are simply a different version of a lithium battery. The polymer is essentially a form of plastic. The great things about polymer batteries, they are light, they are cheap and they hold a lot electricity. I mean, A LOT OF ELECTRICITY. The new chemistry makes them more volatile.
Not your farther's NiCads
One of the largest problems with LiPos are that people treat them like NiCads. It's a new chemistry and a new learning curve. There is a lot more care that needs to be taken with these batteries. You certainly need to tend to them a bit more than NiCads if you want to get the maxium life out of them.
The Storage Mode
If you learn nothing else but this one thing, it would be to do a storage charge with the batteries when you're not using them. It doesn't matter if it's for a drone, a plane, car or boat. The batteries need to be stored properly when not in use. The storage charge is somewhere around a 50% charge. DO NOT FULLY CHARGE A LIPO BATTERY YOU"RE NOT PLANNING ON USING IN THE THE NEXT 24 HOURS.
Exhausted LiPo Batteries.
It's best not to run your batteries into the ground. Many speed controllers have a built-in battery check that shuts off the motor but leaves the servos working when the batteries get to a certain level. Though this may be helpful in keeping your batteries from being exhausted, it can very much suck for you if you are not ready for the loss of power.
LiPo Battery Low Voltage Tester/Buzzer
If you can find space for this, these things are amazing. These things monitor your LiPo battery. They give you readings for each of the battery cells. If one of the cells hits a certain level, say 2.5 volts the battery alarm sounds off. The thing is freaking loud! Can you hear it a couple of hundred feet up? Yes. You can fly until the alarm goes off and still have power to land. You can order it directly from Banggood. You get two for $5 with free shipping, such a deal!
About Charging
When it comes to LiPo's I don't believe in fast charges. Just simply charge your battery before you need to use it. Follow the recommended proceedure for charging your battery with the charger. You will need to use a charger that is designed for charging LiPo batteries. Charge and use the batteries. If you charge and don't use the battery take it and put it on your battery charge and give in a storage charge anyway. There are resistors in the battery charger that will take down the charge to half charge. The charger will get warm. That is your batteries energy being converted into heat.
Charging versus a "balanced" charge.
Each battery is rated by an S The S stands for series. For example, a 3S battery is a series of 3x3.7 volt cells. You can almost think of each cell as a stand alone battery that are connected to each other to give 11.1 volts. If you give it a normal charge and use that nifty battery voltage tester above you'll see some cells have a slightly higher voltage than others. What the balanced charge option does is make sure all three cells (in the case of an S3 battery) have the same charge. It does this by a series of charges and discharges of the cells until they are all equal. A balanced charge takes longer to charge because of the cycles of charging and discharging until they get to equal levels. If you charge your batteries the night before things should be fine. My rule of thumb is, whenever possible, do a balanced charge.
You've charged your cellphone overnight. You've left your laptop charging for days, often leaving the house for many hours. So, what's the big deal with leaving your LiPo batteries unattended when being charged? You're probably charging batteries with either 7 or 11 volts, not a lot of voltage, right?
Though I didn't want to bore you with numbers, in this case, please allow me to show you something. Look at the battery above. It's 2200 Milamp hours. In other words it's 2.2 amps. In theory it can output 11 volts at 2.2 amps for one hour. So, somewhere around 24 watts for an hour. Not impressive? The 50C means something. Multiply it times 2.2 amps. All at once it can discharge 110 Amps. That's one hell of a lot of electricity. The yellow XT60 discharge plug on this battery is hooked up to either 10 or 12 gauge AWG wiring. This is the same gauge range most of the electrical wiring in your home. These battteries are designed to output high amounts of electricy all at once. That's why you need to watch these batteries. They are storing a lot more electricity than what is in your cellphone. You don't need to hover over your batteries, but just the same, you need to be around.
Old/puffy or damaged batteries.
Batteries left charged for long periods of time are around the same as batteries that are left for dead for long periods of time. They soon get puffy. This means that it's time to take the to the e-recycling drive and let them dispose of them for you. The good news is that now these batteries are so cheap you can always get anohter for not a lot of money. If the cell gets damaged, especailly nicked, get rid of it. The potential for fire is too great.
The clay flower pot
One person has suggested getting a $3 clay flower pot from Home Depot and putting your batteries inside when they charge. He claims that any heat, fire or explosion could be contained inside the pot. It may not be a bad place to store batteries as well. Just make sure that nothing flamable is near stored batteries.
LiPo batteries of the future-
I don't believe that the RC hobby has enough momentum behind it to drive great changes in battery technology. But the one thing that does change the dynamic is the miniaturization of the computer technology. Within the next ten years the number of connected technology things in your life will increase dramatically. The one thing they will all have in common is that they will need to be powered by something. Smaller, thinner and even cheaper batteries will be needed.
As demand for batteries grows new ideas will come along I can see the batteries as pre-formed pieces of plastic that clip onto the wings of a plane that would have a simple power connect as a definite possibility in the next few years. It can be a clip on leading edge with a deck for mounting FPV gear.
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