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Hi, and welcome to RCExplorer youtube-videoshow
Today we are going to blow up a LiPo battery and talk about the basics of LiPo's, so stick around
I had planned to talk a little, among the mosquitos and other animals, about LiPo batteries
This is a LiPo battery, a 2s1p, 1000 milli-amp-hour 12 to 18 C battery
And I have planned to explain about all the markings and abbreviations, and there are a lot when it comes to LiPo's
I'm going to start with explaining what f.ex 2s3p means
What this gives is the cell-configuration
The first number gives the number of cells in series 2s - 2 cells in series
After that comes the 3p and that gives the number of cells in parallel
The more cells you have in series, the higher voltage the pack will be, but with the same capacity
The higher number of cells you have in parallel...
Are you bored?
You might be bored also so lets jump to the next thing and that is the C rating...
-But what was the results if you had cells in parallel I don't think you mentioned that, the dog interrupted you
Right, more cells in parallel gives you higher capacity but with the voltage
Now, let me tell you what these 1000 milli amp hours means
It's how many amp hours that is stored in the battery when it's fully charged
This battery holds 1000 milli amp hours
which means that you can load it with 1000 mA and it will last for one hour before it runs out
That is what 1000 mAH means
It's a unit for the amount of charge the battery contains in hours
-So i could draw 500 mA for 2 hours? Exactly
-Or 2000 mA for 1/2 hour? Yes, that is precisely how it works
And that leads us into C ratings and that is how many ampere...
-That's that 12 to 18 that's written on the battery? Yeah, precisely
That's how many amps this battery can supply
The first number, 12, is what it can supply constantly All day long, or at least until it runs flat
-12... How long would the battery last then? -5 minutes
This 18C is what it can deliver in burst I won't have any blood left!
-Mosquito invasion That is how much it can deliver for 30 seconds
Before it gets overheated, after that it needs to cool down for a period of time before it can be used again
A high C rating battery will be physically larger than a low C rating battery
Here I have another 2s 1000 mAH battery - That is nearly the same as the other?
It's precisely the same except, this one is a 12 - 18 C and this one is a 25 - 35 C battery
- That's nearly twice as thick Yeah, and it weighs almost twice
This one got some cell spacings to get better airflow
A higher rating C battery got thicker metal plates inside, and that is all that differs
That leads to lower internal resistance but the price will be higher
A higher C rating battery will hold its voltage better under load than a low C rated battery
So if you would load this battery with 10C the voltage will drop down to, lets say 6 V
And if you draw the same from this battery the voltage will only drop to about 7 volts
Which means that this battery will deliver more watts because it can hold its voltage better
-Why don't you always use a higher C rating battery then? There more expensive, weigh more and it's not always practical
The more C you draw out of a battery with the same capacity, the shorter your flight-time will be
-Yeah, you maybe want more flight time than 5 minutes -and then the other battery will suffice
Precisely, but you should always have more than is needed
Speaking of mAh... It's very important with LiPo's not to discharge them completely
If you would do so, the plates inside the LiPo will oxidize which leads to lowered capacity
And it can't gather energy when charging which leads to a swollen pack that can potentially explode
So, if you discharge a LiPo to much it will become usless
I recommend only using 80% of the rated mAh's -So on that one, 800 mAh's?
Yes. Use a timer when flying, if your not flying an airplane that has very different flight styles
And when you get home, put it on the charger check that you haven't used more that 80% of the capacity
Keep track of this and your battery will last for many more cycles and perform better
because the they hold their C rating better also -Is the C rating reduced by over discharging?
Yes, since the metal plates oxidize it's like having smaller plates which leads to a higher inner resistance
Which leads to the battery producing more heat -So the battery can more easily break even thou
-you didn't go above the 12 C, because there were only 8 "left" Precisely
I recommend balancing the battery when charging This is done by hooking up the battery to a balancer
Because every cell in a battery pack are a little different and every cell is supplying current
It's important that all the cells have the same voltage because when a LiPo cell is discharged bellow 3 V
It starts to oxidize -So one can start oxidize without the rest doing it?
Yes, and when they start getting out of balance one cell might bee at 0,1 V lower than the other cells
So when you charge the pack next time the other cells might be at 4.3 V and one cell at 4.1 V
And next time the battery is discharged that cell is has an even lover voltage then the rest
-It just gets worse It get worse and worse with time
So balance your batteries at least every 10th cycle I balance my packs every time I charge them
Do not use more than 80% of the rated capacity Balance
And fly a lot -Maybe we don't need to say that
Shall we go and check how the explosion of the LiPo is coming? -Yeah, sure.
It should start puffing now...
-I'm scared It will happen any time now
-There you see why you should not leave a LiPo unattended while charging
Look at that
That was all for this time, Subscribe to my videos to be sure not to miss the next strange episode