|11-11-2007, 12:59 PM||#1|
RCC Supreme Contributor
I am: Brian Belanger
Join Date: Nov 2004
Location: Thornhill Ontario
Total Props: 1
Li-Po Care - A to Z
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Ok so theres a bunch of us who know NOTHING about Li-Po's (like me) and what the rules are for charging and discharging and overall care, so I figured I'd get the ball rolling.
Post links and or give advise on charging, discharging, temperature, storage, info about 'balancing' and anything else important to the overall care and performance of your Li-Po battery.
Which ones are good - are there manufacturers that make higher quality batteries than others - are there some that are junk or unsuitable for our applications.
|11-11-2007, 01:45 PM||#3|
LiPo - Lithium Polymers.
Each cell is 3.7 Volts nominal and 4.2 Volts fully charged
(never charge higher than 4.2V per cell)
(never discharge less than 3.0V per cell *to be safe*)
3S - Means 3 Cells in Series (3.6V + 3.6V + 3.6V) = 11.1 Volts
1P - Means parallel
so if each cells is 2200 mAh.. a 3S1P would be
so if each cell is 2200mAh.. a 3S2P would be
3S2P 4400mAh = meaning you have 2 sets of (3.6V + 3.6V + 3.6V)
When Charging or Discharging never let the cells get hotter than 60 Degrees Celcius.
Each Lipo cells manufacturer have different quality and density of cells.
sometimes you see 10C, 15C, 20C, 25C, 30C, 35C
the number is the multiplier & the "C" is for Capacity
eg. a 4S1P 5000mAh 10C pack means..
4S = 14.8 Volts (3.6 * 4)
1P = 1 set of cells
5000mAh = capacity (5Ah)
10C = means that you can only discharge 10 times the capacity continuously (10 * 5 = 50Amps)
- they usually have a maximum burst discharge also, but this means that this battery pack cannot be discharged @ more than 50 Amps continuously and should no be discharged to less than 12 Volts (3.0V * 4)
eg#2. a 4S1P 5000mAh 20C pack means...
Same as above but.
20C = means that you can discharge 20 times the capacity continuously (20 * 5 = 100 Amps)
5000 mAh battery has the same capacity as a 5 Ah battery *it's the same thing*
Most lipos can only be charged @ 1C (meaning 1 times the capacity)
eg. 5000mAh can only be charged @ 5 Amps
But now with newer Lipos, you can charge up to 2C (meaning 2 times the capacity)
eg#2. 5000mAh can be charged @ 10 Amps instead of 5.
PUFFING ! when lipos puff, becareful. This means the cell is damaged. And should "NOT BE USED". It may explode and could cause serious injuries.
Either by: 1) Overheated 2) Discharged exceeded rating 3) Defective cell(s) 4) Charged over 4.2V per cell 5) Cells are unbalanced
BALANCING - Lipos "HAVE" to be balanced mostly when using more than 3S (3 Cells in series). A standalone balancer would work, but newer chargers comes with smart balancing technologies and does this automatically.
If a cell is more than 0.05V difference from other cells, it's considered off balanced and should be balanced.
Best quality Lipos are made in Korea. Enerland & Duralites are top quality cell makers.
This is all I can think of right now... I think there's more stuff..
Hope this Helps..
Store it in a cheap cr*ppy tire steel tool box.. and make metal seperators for them.. just incase if one decides to blow... look up lipo explosions and you'll see why .. You really don't want to lose all those expensive Lipos..
If you're not weight concious, you could always get higher capacity and lower "C" ratings... for example 8000mAh 10C can discharge @ 80 Amps..
Most people buy Maxamps packs.. they're pretty good www.maxamps.com
Money wise packs would be bought from www.truerc.com
|11-11-2007, 02:31 PM||#4|
RCC Pro Contributor
I am: John Summach
Join Date: Aug 2006
Total Props: 0
- Charge them at 1C (eg 4800maH @ 4.8 amps)
- Use a voltage cutoff system on your ESC to prevent over discharging
- You don't need to discharge them after use, just re-peak.
- Store them fully charged
- IMO the Kokam cells that Orion uses are the best (and the hard case is nice too).
Team Orion's LiPo info: http://cms.teamorion.com/orion/instr...in_li_inst.pdf
|11-11-2007, 02:54 PM||#5|
RCC Master Contributor
I am: Bill N.
Join Date: Apr 2006
Location: Purgatory (Ontario)
Total Props: 0
Awesome info guys!!! Keep it coming!! This might have to be a sticky.
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|11-11-2007, 03:00 PM||#6|
Dude, you're absolutely right... Kokam cells are awesome... I think they're enerland cells... Enerland cells are used in Polyquest, Hyperion, Flight Power, Thunder Power, Apex... etc...
|11-11-2007, 05:42 PM||#9|
There are so many links out there with care info...
|11-11-2007, 07:19 PM||#10|
RCC Expert Contributor
I am: Andrew
Join Date: Jan 2006
Total Props: 0
Thank you sooo much guys! I recently got into lipo and was going to ask A LOT of these questions.
Great Idea!!!! Sticky this 4 life!!!!....Or until a new Battery technology comes out.
What are you thoughts on Apogee Lipos? I know they use Lithium Magnesium (Li-Mag) combos and i have heard that they are a lot safer to use and store than your traditional Lipo.
Should I go for these? Are they worth it?, who has expierience with em'?
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