Charging of Lipos

[Ed]

Just got an email showing a fried transmitter from a lipo transmitter battery that exploded when charging. The guys garage was severely damaged. While I don't use a lipo transmitter battery, I do use 5S4P 8000mah TP packs with my Ion and a lipo receiver battery. I presently charge in large metal baking pans with a pot holder underneath on a formica counter top. I am considering going to some kind of enclosed container, either cast iron or ceramic. I would like to know how others are charging, i.e. containers or not. I know not to leave the chargers alone while charging and I have a fire extinguisher ready. Let's hear from you!
Thanks
Ed

[misskimo]

rear , but it happens , but mostly a good name brand lipo will make the chances less to happen , never heard of a thunderpower going off ,
I charge mine without like I have always charged them , like nicds , in the heli , on my table, but I dont leave them either ,

[Laurens]

I wouldn't charge in a metal baking pan. Its far easier to short them.

[ChrisS]

The best/most convienient way I have found is to use a fire safe, available at Home Depot type stores and charge the packs at C/2. I have never had a cell rupture on me, puff yes but never rupture. I think this phenomenon actually takes a pretty major lapse of judgement...like walking away from a charging battery for hours hooked up to a charger or source that is set to put too high a voltage across the cells.

Of those that I know of (there have been 2 or 3) who have had actual fires, the schenario was always the same...flew the packs out hard, left them in the model, hooked them back up to a charger, set it for full tilt and walked away. At some point later on, someone taps them on the shoulder asking if that is his machine over in the distance with all the billowing smoke coming out.

Camplacency with these things is a sure way to loose your model or worse. Pay attention, develop simple and consistant habits and all will be well.

If you are relying on a fire extinguisher, it better be a class D (I think, check me on that). Burning lithium is somewhat similar to burning magnesium in that it burns very hot and liberates oxygen well (do not pour water on a lithium fire). You need the kind of extinguisher that smothers the fire by completely depriving it of oxygen...a bucketfull of sand is better than most Home Depot (ABC?) type extinguishers.

Chris

[mhn]

I have been using an oval pyrex dish, and then cover it with a slightly smaller but similar one.
Do you guys think this is good enough or should I look at another setup for the 5S4Ps?

Michel-Henri

[WayneBrown]

They are HARD to get to burst into flames...
Either denting the packs will short them internally, and cause smoke.. most times only smoke, or overcharging for extended periods at the wrong settings will ruin them.
I intentionally wasted a 3s 1500 pack that had a swelled cell to see just what it would take to make it burn, and almost fell asleep waiting.
To make a long story short, I removed the swollen cell, leaving the other two and resoldered as a 2s pack. Grabbed my ancient charger set to 14v and waited, and waited... about 1/2 hour later it burst into flames. To be fair it swelled within 15 minutes, resulting in a destroyed pack, but it took another 15 minutes to get it lit.

[Hotshot Charlie]

Anyone using the Triton to charge their TP 2100 3s Prolite packs? What's your charge settings?

[chilipepper]

I've been charging the TP2100's 3s Prolite packs with a Triton. I also use the TP cell balancer and have had very good results. I really like the ability to see how much the pack takes. I've been charging at 1.6A for normal use and have gone up to a full 1C for 'quick' charging. I did notice that the cell balancer detects a peak charge a little ahead of the Triton but within a minute or two. I also have the thermal sensor attached and have the cutoff on the low end (not sure right off the top of my head).

So far I've been pleased with my results... however, I would be very curious to hear if I'm doing anything out of the ordinary or dangerous. These are my first LiPo packs and have been a little apprehensive.... but so far so good!

[Hotshot Charlie]

I've been charging at 1.3a, probably too slow....

So, you are quick charging at 2.1a's?

Just wondering what the rest of the gang is charging at????

[chilipepper]

I have been putting 2.1A at it when needed. Both the balancer and the Triton do not seem to mind. The temp on the battery itself has not set off the temp cutoff on the Triton either. Like I said though that is what i'm doing based on the Triton manual and other ramblings around the internet. I would also very much like someone to set us straight or at least give a definitive guideline.

[Hotshot Charlie]

I've always heard a 1C (in this case, 2.1a) is the way to charge Nicad's NiMh, etc. But is it the case with LiPo's?

I have a Hobbico MKII Field Charger that is a dandy little charger for LiPo's at a cheap price, but it won't charge a LiPo or LiIon over a 1.0a charge rate. A friend and myself have put hundreds of charges on the little TP1320 packs and other Apogee 1570 packs, with no problems using the MkII at 1.0a charge rate.

Just a lot that I don't know about this stuff.....

[Laurens]

Rob, a friend is charging his kokam packs on 2C now for a few months, without problems.

[Hotshot Charlie]

Thanks Laurens, that is a hot charge !!! Keep us informed on his pack performance and longevity!

[chilipepper]

Good information: I was just looking at the TP website and re-read the information that came with the packs: http://www.thunderpower-batteries.com/images/THPSafetyWarnings.pdf

They basically say "You must select the charge rate current that does not exceed 1C". It also says that it should be roughly 12.48V to 12.66V after charge which is consistent to what I'm getting out of the Triton Charger. So I would say that it would be pretty safe charging at 1C or below as long as you adhear to the warnings. I guess we'll just have to see what happens over the life of the batteries and compare notes later on to see how people are doing. :^)

[WayneBrown]

I've charged all my lipos at 1C regardless of using the triton or the mkII.
The only battery I've swelled was moments before the night foamie video where I charged at 5C for a few minutes to get a pack up to shoot the video..later this battery was used for the experiment described above.

[WillJames]

I never charger higher than about 1/2C. I have seen numerous people who charge at 1C + puff their packs. If you are not rushing to get your pack charged, why stress it?

[Hotshot Charlie]

why stress it?

Good point, Will !!!!

I do think I will move mine up to 1.5 amp charge. 1.3 may be somewhat conservative...... then again, why change it if it works????

[Laurens]

Why stress it? The problem is that the 1C charging part isn't really its stress point. Its possible without problems to charge faster. Its just like nicd and nimh, you can charge faster then the manufacturer recommends.

[WayneBrown]

Why stress it? The problem is that the 1C charging part isn't really its stress point. Its possible without problems to charge faster. Its just like nicd and nimh, you can charge faster then the manufacturer recommends.
got proof?

I do it on occasion, but I know and accept the risks and am willing to accept the loss of a pack, but not my house.

[Laurens]

That mate that charges them at 2C is enough proof for me. I'm thinking about starting a thread where I will do it with my own pack, updating how much goes in every time.

[WayneBrown]

It would be an intereseting read for sure.
Let us know the draw of your pack on discharge too to a real life comparison.

[Laurens]

Ok Wayne I'm about to start 2 threads in the HF review forum but first I had to ask will permission.