|Apr 30, 2004, 12:25 PM|
Walled Lake, MI, USA
Joined Feb 2000
Yes, it says that 4.3V is the "maximum allowed" voltage per cell. So if you charge a series pack to an average of 4.3V per cell, and if the cells in the pack are slightly out of balance, that means that some of the cells will exceed the absolute maximum of 4.3V. There is also the problem of variation in meters that could lead, for instance, to something measuring 4.3V on a meter when it is actually 4.35V.
Leaving a margin for cell imbalance and meter error is why every single Li-ion cell manufacturer in the world recommends a maximum charger setting of 4.2V per cell. It is dangerous and irresponsible to suggest otherwise. Given the serious risk of explosion and fire with metal-jacketed Li-ion cells, it is simply not worth the potential of personal injury or property damage to exceed the maximum charger setting recommended by all Li-ion cell manufacturers.
|Apr 30, 2004, 02:56 PM|
Photo from sometime back ... iirc the charger was a voltage-limited type (LM317 based I think) setup, pack was left on the charger for a couple of hours before it blew. Battery and Charger was mfg'd for 1/18 scale R/C cars by Novak, they had to issue a recall notice and paid for several damages, so I was told (this fire damaged the car and onboard electronics, and burnt a portion of carpeting, fortunately owner was home at the time of the incident - Novak paid for damages). Novak stop carrying the Li-Ion options and hasn't even bothered to try again.
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