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-   -   overcharger lipo battery grrrrr (https://www.rc-monster.com/forum/showthread.php?t=13467)

Arct1k 07.11.2008 04:16 PM

I have a 606i at home and will test the theory on this tonight - The bigger issue is really that the charger won't have swapped between CC/CV mode when it hit the cutover point.

This may have caused more damage - Time will tell if you have trashed the pack - Hopefully it was not too expensive.

Best of luck

What's_nitro? 07.11.2008 04:23 PM

That is what all LiIon cordless drills have. Protection circuitry built into the pack. I can't imagine how many accidents there would be if the general public had to balance their batteries manually. I think that's also why we don't see LiPo batteries in drills. The risks outweigh the performance gains. It would cost a lot more to have the circuitry, but it would be pretty nice just to be able to put it on the charger and come back in an hour.

Arct1k 07.11.2008 04:27 PM

How do you think your cellphone or laptop battery works - They all have this protection circuitry built in and in the case of a laptop a balancer...

Just open your cell phone up and chances are the battery will be rated at 3.7v i.e. 1s...

Lipo packs are everywhere!

What's_nitro? 07.11.2008 04:35 PM

Yeah even the little stuff has protection built-in. With smaller cells, IE phones, PDAs, etc. they usually don't charge anywhere near a 1C rate. Most of them are 1s so they don't even require balancing, just over-voltage protection. The larger ones like laptop batteries charge more quickly and are multicellular. In fact there have been several instances with laptops going "poof". Most recently a batch of Sony batteries.

Also, these are all Lithium-Ion batteries. Not Lithium-Polymer.

Arct1k 07.11.2008 04:39 PM

Sony failure was due to small metal particles that had contaminated Lithium-Ion battery cells. In a few cases this caused batteries to fail and, in some cases, overheat.

Sony then made changes to its manufacturing process to minimize the presence and size of the particles in its batteries.

The recall was for batteries made during the impacted time.

Arct1k 07.11.2008 04:43 PM

FYI:

Lithium-Ion batteries are constructed with coated anode and cathode foils separated by thin layers of polymer material.

It looks like a jelly roll. You get a high surface area with thin layers. The thinner they go with the separators, the more room there is for the active material.

The coated layers are wound up on machines to create the individual Li-ion cell, and it’s at that stage that contaminants, such as metallic particles, can get embedded in the battery cell. The metallic particles such as happened to Sony may have been cast off by those commercial machines.

Generally, the polymer separator is very thin — less than 25 micron (one millionth of a meter) thick. If that is punctured by an electrically conductive material, like a metal particle, the battery cell’s anode and cathode short circuit.

There is nothing you can do to control this. In contrast, manufacturers have a variety of measures to guard the battery contents from external threats, like ambient heat.

Sony strengthened and reinforced the protective barriers and lining of their battery cells to address the danger of metal particles piercing the lining of the cell.

BrianG 07.11.2008 04:44 PM

One of my former step-kids had a portable DVD player that use actual lipos. And the power/charge jack was directly connected to the battery, the actual charger was in the PS brick (I know this because I checked). Good thing the ex (and her hell spawn) aren't there anymore - I can just imagine what's gonna happen when they can't find the real charger and just plug in whatever will fit...

bl-is-future 07.11.2008 04:51 PM

wow that would not be good for the portable player. Could cause a major problem, but again that comes down to OE. (use the charger made for it) We take for granted what we know on this stuff. something that simple could cause the uninformed some problems with the safety of themselves or others. It all just comes down to paying attention. Doesn't matter what the issue is. Could be charging lipos, or driving to the store. i don't know how many accidents so to speak i have seen where the person involved was not paying attention. There are poor designs but if you pay attention you can catch it. Now i am even guilty of this. I do not pay attention sometimes and it will come back to bite me.

BrianG 07.11.2008 04:53 PM

And no matter how "idiot-proof" you make something, a bigger idiot will come along... :sarcastic:

bl-is-future 07.11.2008 04:57 PM

Now isn't that the truth. I believe it is vintage that has a sig of taking all the warning labels off everything and lets see what happens.
Quote:

Originally Posted by BrianG (Post 190595)
And no matter how "idiot-proof" you make something, a bigger idiot will come along... :sarcastic:


What's_nitro? 07.11.2008 04:58 PM

They're constructed in the same manner as electrolytic/PIO/film capacitors. With capacitors, the rated voltage depends mainly on the thickness of the electrolyte-separating layers. I'm sure if a piece of metal found it's way into a capacitor of sufficient size it could do some real damage as well.

BrianG: Do you know what brand of DVD player it was? Do they still make them with the LiPo cells? That's definitely an accident waiting to happen with all of the charging/protection circuitry in the PS. Was there even a proprietary connector on the charging port?

Arct1k 07.11.2008 05:02 PM

Tell me about it! Do not turn off the traction control on BMW Z3's on wet bendy mountain roads!

Oh to be young and foolish!

What's_nitro? 07.11.2008 05:05 PM

Oh no, was it totalled? Poor thing...

jhautz 07.11.2008 05:17 PM

Quote:

Originally Posted by BrianG (Post 190595)
And no matter how "idiot-proof" you make something, a bigger idiot will come along... :sarcastic:


I'm living proof. :tongue:

Arct1k 07.11.2008 05:23 PM

Quote:

Originally Posted by What's_nitro? (Post 190600)
Oh no, was it totalled? Poor thing...

I slid perfectly sideways into a dry stone wall but didn't roll into the field - wheels were half on and half of the wall.

Two new wheels and tires
New front and rear bumper
New panels down one side
Bent a rear suspension component

No air bags or anything dramatic and no sheep escaped... Car was 6 months old so repaired like new...

But I've never touched that button again on any of my cars even on my 4wd TT...

PS Caution : Bags of Planters Peanuts might contain traces of nuts!


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