Lipo charging and amps

[Rustydiver]

Just starting to charge up my lipos what amps do I charge them at I';ve got an overland ear balanced charger.
Lipos are a 4 cell 14.8v 5000mah one am I right in thinking upto 5amps on this one
And a 3 cell 4000mah and up to 4amp on this one.
I';ve got the 3 cell one on 2 at the moment.

And I understand for about the first 5 charges drain it down to about 50% so what voltage or amps will it be at when it';s there. All this amps volts watts confuses me and I';m easily confused.

Now I';m going to a right plank if 50% is realy 1/2 of 14.8v but knowing battery';s there is a special formula to it.

[Hands0n]

No need to get too deep into the technicalities of battery charging save to say that you should try not to charge at greater than 1C - that is, no greater Amps into the battery than its Amperage rating.  You';ve already got that from what you said; 4amps into a 4000mAh, 5amps into a 5000mAh, 2.2amps into a 2200mAh etc...

LiPo batteries tend to self-condition themselves after several charge/use/discharge cycles.  They start to reach their rated capacity, give or take a few mAh. 

Overall care of a LiPo involves not over-charging the cells, or deep discharging them below 3v per cell.  If you do then you need to get them topped up over 3v as early as you can to minimise any chemical damage to their internals.  And damaged LiPo tend to show it by developing a puffiness to them - a little isn';t dreadful, but if they become bloated then its time to dispose of them carefully and diligently.

The modern day LiPo is quite robust otherwise. 

[Rustydiver]

Thanks for that I now understand about c';s and amps.

So all ok to charge at 2amp for a 4000mah battery it will just take longer.

Is it best to charge under rather than on 1c.

[Hands0n]

Thanks for that I now understand about c';s and amps.

So all ok to charge at 2amp for a 4000mah battery it will just take longer.

Is it best to charge under rather than on 1c.

For general purposes, if you say it takes one hour to charge a 4000mAh battery at 4amps then it is reasonable to expect it to take two hours to charge at 2amps.

To your "best to" question ... It really makes no particular difference to the battery.  As you accumulate a larger collection of LiPo you will start to want to charge as quickly as possible.  That is where you should resist the temptation to charge at greater than 1C. Even if it says on the packet that you can ... Conventional wisdom says to not do so.

[guest325]

Quite often I work out the time to charge several batteries in parallel (on a parallel board from HK) and charge them overnight in a safe place, it usually works out around 0.2/0.25C - charging at this rate is kind to them!
Golden rules don';t charge or discharge too quickly,  don';t use them if they are damaged, try to store them at room temperature.  If you';re going to store them for a long time store at storage voltage at low temperature (in a fridge preferably).
I have some batteries 3 years old now that are still doing what I want them to!

[GdLookinMingeR]

LiPo fire

[guest325]

Thing is nobody told them the fumes were toxic, Lithium burning = Lithium oxide which is similar to Sodium oxide both of which have a great affinity for water, then = sodium (or lithium) Hydroxide (caustic) which doesn';t do your respiratory tract a lot of good!!!

[dp106]

One other thing to consider is the power rating for your charger, ie the max watts.  Not normally something to worry about but charging a 4s 5000mah battery at 5amps will require 84 watts.

16.8 (full voltage of 4s) X 5a = 84 watts.

My charger is rated for 80 watts max so I charge my 4s 5000mah batteries at 4.7a to be on the safe side.

[Friskle]

Thing is nobody told them the fumes were toxic, Lithium burning = Lithium oxide which is similar to Sodium oxide both of which have a great affinity for water, then = sodium (or lithium) Hydroxide (caustic) which doesn';t do your respiratory tract a lot of good!!!

Thats why Lipo bags are also pretty much useless, yes they stop Fire, but sadly your house will still get full of fumes lol

people forget that the fumes are quite toxic.

[teslahed]

What exactly are the fumes? A chemistry expert should be able to tell us pretty easily but i';ve never been able to work it out. I know they smell / taste pretty acrid and horrible but i';ve breathed in small amounts without adverse effects before.

[Friskle]

What exactly are the fumes? A chemistry expert should be able to tell us pretty easily but i';ve never been able to work it out. I know they smell / taste pretty acrid and horrible but i';ve breathed in small amounts without adverse effects before.

Its a carcinogen, where inhalation can casue damage to the tissue in the throat and lungs.

[cosmorogers]

See I just get comfortable charging my growing number of lipos in my room at uni, then someone goes and spoils it by posting something like this!!!!! 

[teslahed]

If you encounter carcinogenic smoke; breath out slowly whilst walking away quickly. Unless you are trapped (as in a house fire) in which case it really is the smoke that kills most people you shouldn';t run into serious problems if you can vacate the area fast.

[Rustydiver]

Thanks guys I wanted to know aboutncharging rates. You';ve given me the Willeies now.

I';m going to find sone off those hollow breeze blocks the type with two holes in the middle small slab top and bottom and store them in the garage. Does it matter how cold they get when being stores. Outside under cover in the dry?

[Friskle]

Thanks guys I wanted to know aboutncharging rates. You';ve given me the Willeies now.

I';m going to find sone off those hollow breeze blocks the type with two holes in the middle small slab top and bottom and store them in the garage. Does it matter how cold they get when being stores. Outside under cover in the dry?

Somewhere cool and dry, being honest, mine are all under the stairs, on a shelf, now many will say thats dodgy, maybe it is, but in quite a good few years i have never had one pop on thier own, unless i have done it on purpose outside.

and no matter what the makers say, i only charge all my batts at 2A.

[guest325]

Its a carcinogen, where inhalation can casue damage to the tissue in the throat and lungs.

Not quite:
http://www.espimetals.com/index.php/msds/650-lithium-oxide

[Friskle]

yes true,, even getting the compound on your skin is just as dangerous, you have all these videos knocking around, yet none of them really mention the fumes can seriously injure or kill you if to much inhaled, all they bother about is the fire they make...

i punctured a 14.8v dodgy battery a while back, fully charged of course :) but ended up breathing a lot in, i had what felt like toncillitis for about three days, really bad head aches and felt terrible, mind you, still not put me off "disposing" of them in that manner lol