Cheap consumer devices that overcharge their own cells

[zipplet]

Hi,

I have a MadCatz wireless nunchuk for Nintendo Wii, the same as this one on amazon:

http://www.amazon.co.uk/dp/B002ECE8XM/

It has always taken a while to charge up, and today it did not ever seem to finish charging (red LED goes out when it finishes). So I disassembled it. It uses a Lithium Ion battery, and I measured it at 4.29V, that is after resting about 30 minutes. Very dangerous!!!

I wonder how many other cheap consumer devices with li-ion cells do this... maybe cheap devices should stick with NiMH cells.

I will be disposing of the device.

 

[aimxplode]

How are explosions not happening more frequently from these poor quality, poorly designed products?

 

[zipplet]

How are explosions not happening more frequently from these poor quality, poorly designed products?

This is what worries me. Perhaps, a mild overcharge combined with a low current application has a lower risk of venting (but it would still damage the cell). BTW, the meter I used to measure the cell is a calibrated one I also use when testing li-ion cells for lights, so I know the reading is fairly accurate.

 

[Shadowww]

Also such electronics, unlike flashlights, are not waterproof, therefore there won't be any high pressure build-up inside them.

 

[bshanahan14rulz]

Phew, that's a relief! I can handle a controller venting flames, that's no big deal.

 

[Shadowww]

Phew, that's a relief! I can handle a controller venting flames, that's no big deal.

It's hard to get cell to vent flames either. I tried to (in controlled conditions, of course) overcharge a Panasonic NCR18650A to 4.5V, and, apart from it heating up, nothing of explosive/flaming kind has happened.

 

[jasonck08]

Hi,

I have a MadCatz wireless nunchuk for Nintendo Wii, the same as this one on amazon:

http://www.amazon.co.uk/dp/B002ECE8XM/

It has always taken a while to charge up, and today it did not ever seem to finish charging (red LED goes out when it finishes). So I disassembled it. It uses a Lithium Ion battery, and I measured it at 4.29V, that is after resting about 30 minutes. Very dangerous!!!

I wonder how many other cheap consumer devices with li-ion cells do this... maybe cheap devices should stick with NiMH cells.

I will be disposing of the device.

Are you sure it is overcharging the cell? There are more and more cells that use 4.3 and 4.35v charge voltages including cylindrical and prismatic / pouch cells. Some of the modern cell phones out use 4.3v Li-ion cells.

 

[bshanahan14rulz]

Is it a pouch cell or an 18650? After Shadowww's comment, I may have to eat my own words if it is an 18650, which would fit in that controller very nicely. I would guess that if it were a name-brand pouch cell, it would be fairly obvious, and quite possible that it is a newer chemistry as well.

 

[zipplet]

I did consider the possibility of it being a higher voltage cell. However, since the controller would not terminate even when left charging for over 12 hours (I forgot!) when it used to charge after 3 hours or so, it was overcharging.

It was a weird cell - a prismatic with a hard case. No branding evident on the packing. The cell was pretty small - the kind of size of those used in the iPod shuffle, but a bit fatter.