Re: 1502 TDR project

Tom Gardner
 

On 11/12/19 15:38, John Griessen wrote:
On 12/11/19 8:59 AM, Chuck Harris wrote:
Everything you say is absolutely true, as long as
you never, ever, ever allow a cell to reverse charge.
So, just stopping the pack discharge is not enough.
The cells need to be managed separately as in today's
lithium ion battery manager IC's and no cells in series...
A cell cannot reverse charge itself. The weakest cell in a battery can be reverse charged as the other cells continue to discharge themselves through the load.

If there is no complete circuit (e.g. battery pack not connected to a 1502), then a cell can only self-discharge.

A NiCd cell should be capable of being continuously trickle charged at the C /10 rate or lower, independently of whether or not it is in a battery. If you want to "trickle" charge a NiCd battery at >C/10, then it would be prudent to manage each cell individually.

It is not entirely clear to me whether the C/10 rate is peak or mean. In the 1502 the peak current each 20ms (or 16ms in the US) is noticeably more than the mean current. In the 1502, R6131 sets the mean current to be around C/10.

Other chemistries, especially Li, cannot tolerate continuous trickle charge and each cell has to be managed individually.

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