Re: Roundshot charger?

[Alan & Shari Kafton <shmooze@xxxxxxxxx>]

Dforth617@xxxxxxx wrote:
> 
> I just received a new charging unit for my 35s Roundshot, I dropped the
> original one and it ceased to function.  I have a question to anyone out
> there that knows  something about electricity.  The original charging unit (
> the dropped one) was a 9V  DC at 500ma output and the new one is 6VDC at
> 300ma.  Why the difference in voltage output from one unit to the next?
> Natural assumption would be that all 35/35s charging units would all be the
> same ??
> 
> Don


Don,

My Roundshot 35 charger, made by Calrad, is also rated at 6 volts @
300mA.

I should add, however, I doubt your old charger would make much
difference!  

While my charger is labled 6 volts, the actual OPEN CIRCUIT voltage is
9.6 volts, and when it is plugged into the camera for charging, the
terminal voltage drops down to about 3.9 volts.  Basically the battery
becomes a current sink on the dc charger, loading it down until it's
output voltage equals the battery's terminal voltage.

Primitive, but given the substantially overdesigned battery source built
into the Roundshot (i.e. 100 roll charge capacity), who cares if
capacity is degraded somewhat by so-so battery management.

By the way, the best thing you can do to extend the life of your
batteries it NOT TO OVERCHARGE THEM!  The manual says nominal charging
time is 12 hours, but I measured the charging current on my camera, did
some rule-of-thumb calculations, and for my camera believe a full charge
from a completely discharged state is 8-9 hours!

I also don't charge it everytime I go out and shoot....I've had the
camera more than 2 years, never replaced the batteries, and haven't been
caught short on charge yet....

Good luck & happy shooting,

--Alan Kafton