[Beerwiser]

Posts not relevant to this subject will be removed after a few days to keep the thread on topic.

Lipo Battery basics

Unlike conventional NiCad or NiMH battery cells that have a voltage of 1.2 volts per cell, LiPo battery cells are rated at 3.7 volts per cell. A fully charged cell is 4.21V and a dead cell is 3.0V which you never want to go below.

So if you got a battery such as a Flight Power that I have in my hand which has these numbers on it, this is what each of the numbers mean:

1200 mAh 3s 11.1V Li-Po
30C 36 Amp continuous 60C 72 Amp max bursts

First mAh= milliamp hours: how many milliamps you can draw for one hour before the battery is completely dead. This particular battery has a rating of 1200mAh so you can draw 1200ma for 1 hour before the battery is dead. Or you can draw 600mA for 2 hours or 2400mA for 30 minutes etc.

3s= 3 cells hooked in series. Like I said earlier each cell has a rating of 3.7V/cell so this battery has a voltage of 11.1V (3X3.7=11.1) When this battery is fully charged it will be at 12.63V (4.21X3) and when it is fully discharged it would be at 9V(3X3v). Some batteries will have a 3S2P. The 2P part means that there are cells hooked up in parallel, therefore doubling the capacity. If it were a 3S3P the capacity would be tripled and so on. When you hook cells up in parallel you don't increase voltage you just increase the amperage of the battery just like boosting a car battery.

30C means the capacity draw of the battery. On this battery 1C=1.2Amps (1200mAH/1000=1.2C). So under normal flying this battery can safely deliver 30C or 36 Amps continuously. This battery will also able to provide you with 60C or 72Amps of power in short burst.

Hopefully this help some people out.

Thanks To Michel Gravelle for posting this link, full of info on all your lipo question
http://sites.google.com/site/tjinguy...arging-how-tos

[canadianf1pilot]

thanx Beerwiser... I spent a day surfing the web for info just like that....I am sure it will help out us old time slimers break our glow habit...LOL

Bill

[Beerwiser]

Lol, I like my glow personally; it just seems everything use batteries even if there is gas involved

[michel gravelle]

Hi

Will this help , ( or add to youre thread )
http://sites.google.com/site/tjinguy...arging-how-tos


Michel

[canadianf1pilot]

Lots of good info there Michel, I missed that one on my search for info.

Bill

[Beerwiser]

I have to agree with Bill, I never seen that site either when I was looking. Very nice site, thanks for posting it.

[Rimripper]

Also when running lipo's I use a 80% rule,so if the lipo is good for 1200 mah I would only use 960 mah out of it.I find that this gives alot longer life to the lipo and helps it hold the voltage load over time.

Ive also been breaking my lipo's in with constant amp draw when I first get them,starting with low amps,discharging out 1/3 of the pack recharge then reapeat.Ill do this all the way up to 65-70 amps using the constant amp draw,then I will fly with moderate throttle pulling slightly higher amps that will flucuate.

I say the 65-70 amp draw as this was an example I used to break in 180amp lipo's.

Now when I fly and push my lipo's hard,then download the data from the flight,it seems the lipo's hold very well under high amp loads.

[michel gravelle]

Originally Posted by Rimripper

Also when running lipo's I use a 80% rule,so if the lipo is good for 1200 mah I would only use 960 mah out of it.I find that this gives a lot longer life to the lipo and helps it hold the voltage load over time.

Ive also been breaking my lipo's in with constant amp draw when I first get them,starting with low amps,discharging out 1/3 of the pack recharge then repeat.Ill do this all the way up to 65-70 amps using the constant amp draw,then I will fly with moderate throttle pulling slightly higher amps that will fluctuate.

I say the 65-70 amp draw as this was an example I used to break in 180amp lipo's.

Now when I fly and push my lipo's hard,then download the data from the flight,it seems the lipo's hold very well under high amp loads.

Hi

You are right ,....... of course ,................. but these days things change ,........... awfully fast . And ,... I think the 80% rule is a keeper . A123,s don,t have this rule , " I think " .

Michel

[Helno]

Steps to dispose of a lipo battery.

1) Discharge the lipo slowly with a lightbulb
2) Verify no volts with a multimeter
3) Twist the discharge leads together to ensure any residual voltage is bled off
4) Throw away in municipal garbage (no heavy metals in these batteries)

Do not immerse it in saltwater
This will only corrode away the tabs and will not actually discharge the cells leaving you will a battery that still contains energy and poses a fire risk.

[SARPLT]

RCHELICOPTERFUN.COM has one of the most informative articles on Lipo batteries that I have come across. It is located at the following website and is called "Understanding RC Lipo Batteries". Happy reading.
http://www.rchelicopterfun.com/rc-lipo-batteries.html