A complete Newb to LIPOS

[Bun]

:twisted: No matter where i go, i can't find good information on how to exactly charge a LIPO, all i read is don't do this, don't do that, or it'll blow up :twisted: I know LIPOS are dangerous, but at least show me how to charge one :roll:

I've got this a prolux 3 cell charger link if u wanna see: http://www.rcgroups.com/forums/showthread.php?t=272662

My question is, what do i have to do and look for, when i want to charge a LIPO say, 11.1v, 3 cells, 1000 mah. What is the C rating that everone talks about, 15C or whatever.

I tried charging a lipo, by makng my own wires from an electrical main. That was a joke by the way :lol:

Kind Regards,
Chetan

[MicroMan]

I did a little searching and found this ]PDF document on LIPO saftey and how to charge them. I hope this is what youre looking for. Dont forget your Ammo can lol.

http://www.thunderpower-batteries.com/images/THPSafetyWarnings.pdf#search=%22lithium%20polymer% 20battery%20safety%22

[kgfly]

Unfortunately your first mistake was buying a cheap charger without a decent user interface, instructions or the ability to monitor the health of your batteries. If possible, return it and get a SwallowAdvance, Cellpro4S, Hyperion or similar.

"C" represents the nominal 1hr discharge rate. For a 1000mAh battery, 1C=1000mA=1A, 15C=15A. The battery has 3 key ratings: No. of cells/voltage, capacity (mAh) and maximum continuous and burst discharge rates. For example,
3S 2200 15C/20C means: 3 cells = 3 x 3.7 = 11.1V, 2200 mAh, 15C (=33A) continuous/44A burst discharge rate.

Most lipo cells should never be charged above 1C. For a 1000mAh battery that means never charge above 1A.

The charging process is:

1) Check all settings on your charger match the battery (no. of cells, max charging rate)
2) Connect power to the charger
3) Connect the battery
4) Start charging

Never leave a lipo charging unattended. Ideally charge in a fire-safe location or container (eg if indoors, in a pyrex bowl).

[Bun]

Oh ok now i get it :D

Don't worry i cancelled my order on that charger. Will it take longer and be safer if i charge at a slower rate? (just be 100% sure). Also no matter what rate i charge it at, how will i know when it's charged, do i just have to trust the charger when it says finito? Also do i need a balancer? Is having a balancer really important, or not that nessessary..not sure.

LIPO scare me, is it possble instead to use a NiMh battery on a trex? I love the feeling that my house is not gonna go on fire that easy. I'm just gonna be doing basic hovers, and sport flying, not 3d

Kind Regards,
Chet

[kgfly]

All chargers have some way of indicating that they are finished. The better ones have an LCD display which reports the final voltage on each cell and the total charge returned to the battery. When fully charged the cells should be at (or close to) 4.2V each (12.6V total for a 3S battery).

Have a look at this thread: http://www.helifreak.com/viewtopic.php?p=177410#177410

and at this charger which is a nice integrated charger/balancer and is getting good reviews: http://www.rcaccessory.com/index.asp?PageAction=VIEWPROD&ProdID=123

A balancer ensures that all cells in a battery pack are charged to the same voltage. This is important on two counts. Firstly, a charger that only monitors the overall battery voltage is at risk of overcharging some cells. Consider a 3S battery with one low cell at 4.1V and 2 others at 4.2V. The charger will see 12.5V and keep pumping current into the battery. This could push the two high cells into a dangerous over-charge state. Secondly, on discharge out of balance cells can be drained differentially which will accentuate the imbalance. This can cause the low cell(s) to go into an over-discharge state.

So IMO, balancing is a good thing for reducing risk and ensuring maximum lifetime and performance from your batteries. You can get a charger and a separate balancer but an integrated balance charger is more convenient and the BC5 looks like an excellent choice. If I was buying a charger today, that would be the one.

[kgfly]

is it possble instead to use a NiMh battery on a trex

I doubt it. I think you would need a 9S battery (9 * 1.2 = 10.8V nominal) and I doubt you could get one with enough capacity (mAh) that would still fit. I doubt that AA size NiMH cells could provide the current (say 10A cont, 20A burst) and I don't think 9 x sub-C would fit. At a similar capacity I think they are about twice the weight of LiPo so that would be a problem too.

[Bun]

How does this charger look :lol:

http://cgi.ebay.com/RC-R-c-helicopter-smart-lipoly-battery-balance-charger_W0QQitemZ250020165747QQihZ015QQcategoryZ25 63QQtcZphotoQQcmdZViewItem

Thats just a link of the features, my mate has one of those which he is willing to sell me, iis this a good charger? It balances, has good protection and shows the voltages of each cell :lol: