Bob Axtell wrote:
> Rolf wrote:
>   
>> Hi all. I am hoping to tap in to the collective experience on the list...
>>
>> I have a project ("advanced" shutter-release system for a camera - 
>>     
>
[snip]
> Just be very careful when charging Li-Ion cells. Use a quality 
> self-contained chip to do it with; DON'T
> use a PIC to charge the battery. Proper charging requires a thermistor 
> to measure battery temperature.
>
> My personal preference is to NOT use Li-Ion, but to use NiMH cells, 
> which are quite safe and are being
> constantly improved. (The inherent instability of Li-Ion cells and the 
> problem with Chinese manufacture of
> defective cells cause me not to use them.)
>
> In any case:  Good luck.
>
> --Bob 
>   

Thanks, Bob.

Yes, I have studied the Li-Ion process carefully before selecting them. 
Even obtaining the cells is a challenge... ;-)

In my case I have chosen the LTC1733 to manage the charging process. The 
PIC simply monitors the LTC1733 which is purpose-built for the task and 
has a number of safety concepts built in. My larger safety issue is just 
having the cell plugged in to a bread-board where the danger of shorting 
one is not unreasonable (I have already).

I initially built a prototype charging circuit, created a charging PCB 
module, and then tested it thoroughly. I have included that module in 
the breadboard.... (The LTC1733 is only available as SMT).

I have charged and discharged a number of different cells using my 
prototype in a safe environment.

Rolf

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