At 08:17 AM 11/22/2016, you wrote:
Since the original battery for the 817 was I think a 1400 mAh battery I
would choose the 10 hour
charge time for the first charge cycle, then depending on how deeply it
is discharged maybe the
8 hour after that. Now you didn't say what the battery is, CD, NiMa or
what those I think are the only
two you can charge on the internal charger.
Marty kd8bj
Some battery basics....
Charging NiCd or NiMh cells is pretty straighforward. For a standard "slow charge" of all cells in series without any end of charge detection (ie., the way the FT817 does it), apply a current of between 1/10 and 1/20 of the pack capacity. 1/10 capacity is the standard NiCd charge and can be used with NiMh but 1/20 is a better idea for NiMh. Ignoring inefficiency, the duration will be the pack capacity divided by the charge current. Note that at this low charge rate, it is NOT necessary to detect end of charge for short durations.... simply charge longer than the pack capacity divided by the charge current and call it good.
The FT817 charges at (as I recall) 160mA, which is (give or take) appropriate for both NiCd and NiMh.
So for example, consider a pack consisting of AA NiMh cells. Probably in the 2000mAH capacity range. Not considering inefficiency, the required charge time for completely dead would be 2000/160=12.5 hours. More is OK.... even preferred because it ensures that all cells are fully charged. Less is also OK, but you just won't be fully charged and the individual cells may be at different states of charge.
When I charge (I use NiMh cells), I set 10 hours and do it twice ;) Again, at this current level, taking the pack into overcharge is good unless it is left that way for many days.
Paul
WA9PUL
Paul Goelz
Rochester Hills, MI
pgoelz@...
www.pgoelz.com
